Boost page navigation with htmx

Links and GET forms to wiki pages swap the next page into .shell instead
of loading a new document: the server answers boosted requests and
history restores with a partial (title, page actions out-of-band, shell
content). The header stays, browsers without cross-document view
transitions (Firefox) no longer flash between pages, and the swap runs
as a same-document view transition. Files, the editor, internal
endpoints and POST forms still navigate normally.

Back/Forward refetch pages (no snapshots that could predate a move or
delete); the tree rail keeps its scroll position and the content column
returns to where it was. Mutation redirects swap their result in the
same way. Page scripts that assumed a fresh document now also run after
a swap (toc, contents, companion, scroll-sync, search actions) or
register once (fitness).

The e2e suite now also runs in Firefox.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Makefile

@@ -11,7 +11,7 @@ RELEASE_FLAGS := -trimpath -ldflags="-s -w"
 EDITOR_BUNDLE := assets/editor/vendor/codemirror.bundle.js
 EDITOR_SRCS := $(wildcard editor-build/*.js) editor-build/package.json editor-build/package-lock.json
 
-.PHONY: deploy companion companion-windows companion-linux companion-release editor
+.PHONY: deploy companion companion-windows companion-linux companion-release editor e2e
 
 # Cross-compiled companion artifacts the wiki binary embeds. Both must exist
 # before `go build .` so embed.FS picks them up.
@@ -46,3 +46,8 @@ deploy: companion-release
 	scp datascape-arm $(NAS):/share/homes/luxick/.local/bin/datascape
 	ssh $(NAS) /share/homes/luxick/.local/bin/datascape-start.sh
 	rm datascape-arm
+
+# Browser end-to-end tests (Playwright driving the system Chrome). Builds the
+# wiki binary and runs it against a throwaway wiki in e2e/.tmp.
+e2e:
+	cd e2e && npm install --no-audit --no-fund && npx playwright test

assets/companion.js

@@ -200,13 +200,20 @@
         // leaves the status icon and reveal buttons invisible on mobile.
         if (isMobileDevice()) return;
         probeStatus().then(function () {
-            updateFooterIcon();
-            wireFileLinks();
-            wireRevealButton();
-            wireFileRevealButtons();
+            wireFileLinks(); // delegated to document: once
+            applyToPage();
+            // Boosted navigation swaps in a new page without reloading this
+            // script: re-apply to its footer icon and reveal buttons.
+            document.addEventListener('page:swapped', applyToPage);
         });
     }
 
+    function applyToPage() {
+        updateFooterIcon();
+        wireRevealButton();
+        wireFileRevealButtons();
+    }
+
     if (document.readyState === 'loading') {
         document.addEventListener('DOMContentLoaded', init);
     } else {

assets/fitness/fitness.js

@@ -2,6 +2,11 @@
 // reloads the page with that chart's query parameter updated. Plain GET
 // navigation — each view is distinct and bookmarkable, so no
 // postReplace/history handling is needed.
+// Boosted navigation re-runs this script on every visit; the listeners
+// are delegated to document, so register them once.
+if (!window.fitnessWired) {
+window.fitnessWired = true;
+
 document.addEventListener('change', function (e) {
     var url = new URL(window.location.href);
     var sel = e.target.closest('[data-fitness-range]');
@@ -72,3 +77,4 @@ document.addEventListener('pointermove', function (e) {
     tip.style.left = left + 'px';
     tip.style.top = top + 'px';
 });
+}

assets/hx.js

@@ -0,0 +1,140 @@
+// Site-wide htmx policy. Loaded right after htmx itself.
+(function () {
+    // htmx wires up swapped-in content (e.g. a dialog's hx-post form) in its
+    // settle step, by default 20ms after the swap: a click or Enter in that
+    // window would submit the form natively. No settle transitions are used,
+    // so settle in the same tick.
+    htmx.config.defaultSettleDelay = 0;
+
+    function boosting() {
+        return document.body.getAttribute('hx-boost') === 'true';
+    }
+
+    // A server-sent HX-Redirect follows a mutation (move, delete, …): load the
+    // target into the current history entry rather than pushing a new one, so
+    // Back skips the stale pre-mutation page. Boosted pages swap it in like a
+    // navigation; elsewhere replaceState + reload (not location.replace: a
+    // target differing only by #fragment would otherwise not re-fetch).
+    htmx.location = {
+        set href(target) {
+            if (boosting()) {
+                if (window.closeModal) closeModal();
+                htmx.ajax('GET', target, {
+                    target: '.shell',
+                    swap: 'innerHTML transition:true',
+                    headers: { 'HX-Boosted': 'true' },
+                    replace: target
+                });
+                return;
+            }
+            window.history.replaceState(null, '', target);
+            window.location.reload();
+        },
+        reload: function () { window.location.reload(); }
+    };
+
+    // Failed requests answer with a plain-text reason; show it. A failed
+    // boosted navigation falls back to loading the page normally instead.
+    function fallBack(e) {
+        if (!e.detail.boosted) return false;
+        window.location.href = e.detail.pathInfo.finalRequestPath || e.detail.pathInfo.requestPath;
+        return true;
+    }
+    document.addEventListener('htmx:responseError', function (e) {
+        if (fallBack(e)) return;
+        var xhr = e.detail.xhr;
+        alert(xhr.responseText || ('Request failed (' + xhr.status + ')'));
+    });
+    document.addEventListener('htmx:sendError', function (e) {
+        if (fallBack(e)) return;
+        alert('Network error');
+    });
+
+    // --- Boosted navigation ---------------------------------------------
+    // Outside the editor, links and GET forms to wiki pages load the next page
+    // into .shell instead of replacing the document: the server answers with
+    // the "partial" (title, page actions out-of-band, shell content). The
+    // header stays put, nothing flashes in browsers without cross-document
+    // view transitions, and the swap runs as a same-document view transition.
+    // Back/Forward refetch the partial (hx-history="false" on .shell: no
+    // snapshots that could show a page from before a move or delete).
+    htmx.config.scrollIntoViewOnBoost = false;
+
+    // Only wiki pages are boosted: same origin, a slash-terminated path, no
+    // query except a search (?q=). Files, the editor (?edit), internal
+    // endpoints (/_…) and POST forms navigate normally.
+    function isPageURL(url) {
+        if (url.origin !== location.origin) return false;
+        if (!url.pathname.endsWith('/') || url.pathname.indexOf('/_') === 0) return false;
+        var ok = true;
+        url.searchParams.forEach(function (v, key) { if (key !== 'q') ok = false; });
+        return ok;
+    }
+
+    // htmx decides per element whether it is boosted, right after this event.
+    document.addEventListener('htmx:beforeProcessNode', function (e) {
+        var elt = e.target;
+        if (elt.hasAttribute('hx-boost')) return;
+        var page = false;
+        if (elt.tagName === 'A') {
+            page = elt.hasAttribute('href') && !elt.hasAttribute('download') && isPageURL(new URL(elt.href));
+        } else if (elt.tagName === 'FORM') {
+            page = (elt.getAttribute('method') || 'get').toLowerCase() === 'get' && isPageURL(new URL(elt.action));
+        } else {
+            return;
+        }
+        if (!page) elt.setAttribute('hx-boost', 'false');
+    });
+
+    function isShell(elt) {
+        return elt && elt.classList && elt.classList.contains('shell');
+    }
+
+    // Scroll positions: the tree rail keeps its position across navigation;
+    // the content column (.center) starts at the top, or where it was when
+    // coming back via Back/Forward.
+    var treeTop = 0;
+    var restoring = false;
+    var centerTops = {};
+    function pageKey() {
+        return location.pathname + location.search;
+    }
+    function rememberTree() {
+        var tree = document.querySelector('.tree-scroll');
+        treeTop = tree ? tree.scrollTop : 0;
+    }
+    document.addEventListener('scroll', function (e) {
+        var t = e.target;
+        if (t.classList && t.classList.contains('center')) centerTops[pageKey()] = t.scrollTop;
+    }, { capture: true, passive: true });
+
+    document.addEventListener('htmx:beforeSwap', function (e) {
+        if (e.detail.boosted) {
+            e.detail.target = document.querySelector('.shell');
+            e.detail.swapOverride = 'innerHTML transition:true';
+        }
+        if (isShell(e.detail.target)) rememberTree();
+    });
+    document.addEventListener('htmx:historyCacheMissLoad', function () {
+        restoring = true;
+        rememberTree();
+    });
+
+    // After a new page is in .shell: restore scroll positions, then tell page
+    // scripts (companion.js, …) to apply themselves to the new content.
+    document.addEventListener('htmx:afterSettle', function (e) {
+        if (!isShell(e.target)) return;
+        var tree = document.querySelector('.tree-scroll');
+        if (tree) {
+            tree.scrollTop = treeTop;
+            var active = tree.querySelector('.tree-row.is-active');
+            if (active) active.scrollIntoView({ block: 'nearest' });
+        }
+        if (restoring) {
+            restoring = false;
+            var center = document.querySelector('.center');
+            if (center) center.scrollTop = centerTops[pageKey()] || 0;
+        }
+        document.dispatchEvent(new CustomEvent('page:swapped'));
+    });
+})();

assets/layout.html

@@ -8,6 +8,8 @@
         <link rel="preload" href="/_/fonts/IosevkaEtoile.woff2" as="font" type="font/woff2" crossorigin />
         <link rel="preload" href="/_/fonts/IosevkaSlab.woff2" as="font" type="font/woff2" crossorigin />
         <link rel="stylesheet" href="{{asset "style.css"}}" />
+        <script src="{{asset "vendor/htmx.min.js"}}" defer></script>
+        <script src="{{asset "hx.js"}}" defer></script>
         <script src="{{asset "modal.js"}}"></script>
         <script src="{{asset "global-shortcuts.js"}}"></script>
         <script src="{{asset "history-nav.js"}}"></script>
@@ -16,10 +18,13 @@
         <script src="{{asset "tree-picker.js"}}"></script>
         <script src="{{asset "companion.js"}}" defer></script>
         {{if not .EditMode}}<script src="{{asset "overlay.js"}}" defer></script>
-        <script src="{{asset "tree-sidebar.js"}}" defer></script>{{end}}
-        {{block "headScripts" .}}{{end}}
+        <script src="{{asset "page/actions.js"}}"></script>
+        <script src="{{asset "search/actions.js"}}"></script>{{end}}
     </head>
-    <body>
+    {{/* Outside the editor, links to pages are boosted: htmx swaps .shell
+    (plus title and page actions, see "partial") instead of loading a new
+    document. hx.js decides which links count as pages. */}}
+    <body{{if not .EditMode}} hx-boost="true"{{end}}>
         <header>
             <nav class="breadcrumb row">
                 <a href="/" tabindex="-1" title="Home"><svg class="logo" viewBox="0 0 26.052269 26.052269" xmlns="http://www.w3.org/2000/svg"><g fill="none" stroke="currentColor" stroke-linejoin="miter" transform="matrix(0.05463483,8.1519706e-6,-8.1519706e-6,0.05463483,-64.560546,-24.6949)"><rect x="1188.537" y="457.92056" width="461.87488" height="462.15189" stroke-width="20.2288"/><path d="m1348.9955 456.59572.046 309.36839" stroke-width="19.6849"/><path d="m1200.3996 765.80237 441.8362-.0659" stroke-width="19.6849"/><path d="m1648.2897 620.244-299.2012.0446" stroke-width="20.5676"/><path d="m1491.6148 909.24806-.021-136.93117" stroke-width="19.6849"/><rect x="1191.6504" y="461.66092" width="457.09634" height="457.09634" stroke-width="19.6761"/></g></svg><span class="app-name"> datascape</span></a>
@@ -35,48 +40,67 @@
                 <span class="dropdown actions">
                     <button type="button" class="btn actions-toggle" data-action="actions-menu" aria-haspopup="true" aria-expanded="false" title="Actions">ACTIONS</button>
                     <div class="dropdown-menu align-right actions-menu">
-                        <div class="actions-special"></div>
-                        {{template "headerActions" . }}
+                        {{template "page-actions" .}}
                     </div>
                 </span>
                 {{end}}
             </div>
         </header>
-        <div class="shell">
-            {{if not .EditMode}}<aside class="tree-sidebar col">
-                <div class="tree-scroll"></div>
-                <script>
-                    // Paint the previous page's tree before first render so the rail
-                    // doesn't flash empty; tree-sidebar.js swaps in the live tree.
-                    (function () {
-                        try {
-                            var s = JSON.parse(sessionStorage.getItem("tree-snapshot"));
-                            if (!s) return;
-                            var el = document.currentScript.previousElementSibling;
-                            el.innerHTML = s.html;
-                            var a = el.querySelector('a.tree-name[href="' + CSS.escape(location.pathname.replace(/\/*$/, "/")) + '"]');
-                            if (a) a.parentNode.classList.add("is-active");
-                            el.scrollTop = s.top;
-                        } catch (e) {}
-                    })();
-                </script>
-            </aside>{{end}}
-            <div class="center">
-                <main>
-                    {{block "content" .}}{{end}}
-                </main>
-                <footer>
-                    <span class="muted">Request: {{.RenderMS}} ms</span>
-                    {{block "footerExtras" .}}{{end}}
-                    <span class="dropdown companion-status" data-companion-status hidden>
-                        <button type="button" class="btn btn-small companion-icon" data-action="companion-toggle" title="Companion status" aria-label="Companion status">○</button>
-                        <div class="dropdown-menu align-right open-up companion-flyout"></div>
-                    </span>
-                </footer>
-            </div>
-            {{if not .EditMode}}{{block "aside" .}}{{end}}{{end}}
-        </div>
+        <div class="shell" hx-history-elt hx-history="false">{{template "shell" .}}</div>
         {{block "extras" .}}{{end}}
+        <div id="modal-host"></div>
     </body>
 </html>
 {{end}}
+
+{{/* The page-specific header actions; the partial swaps them out-of-band
+(the attribute is inert in a full page). */}}
+{{define "page-actions"}}<div id="page-actions" class="page-actions" hx-swap-oob="true">
+    <div class="actions-special">
+        <button type="button" class="btn btn-block" title="Folders" onclick="openOverlay(document.querySelector('.tree-scroll'))">FOLDERS</button>
+    </div>
+    {{template "headerActions" .}}
+</div>{{end}}
+
+{{define "shell"}}
+{{if not .EditMode}}<aside class="tree-sidebar col">
+    <nav class="tree-scroll" aria-label="Folders">{{.Tree}}</nav>
+    <script>
+        // Full page loads: keep the rail's scroll position (before first
+        // paint, so it doesn't jump), then reveal the active row. Boosted
+        // navigation keeps it itself (hx.js); this script re-runs then and
+        // bails out.
+        (function () {
+            if (document.readyState !== "loading") return;
+            var el = document.currentScript.previousElementSibling;
+            try { el.scrollTop = +sessionStorage.getItem("tree-scroll") || 0; } catch (e) {}
+            var active = el.querySelector(".tree-row.is-active");
+            if (active) active.scrollIntoView({ block: "nearest" });
+            addEventListener("pagehide", function () {
+                var cur = document.querySelector(".tree-scroll");
+                try { sessionStorage.setItem("tree-scroll", cur ? cur.scrollTop : 0); } catch (e) {}
+            });
+        })();
+    </script>
+</aside>{{end}}
+<div class="center">
+    <main>
+        {{block "content" .}}{{end}}
+    </main>
+    <footer>
+        <span class="muted">Request: {{.RenderMS}} ms</span>
+        {{block "footerExtras" .}}{{end}}
+        <span class="dropdown companion-status" data-companion-status hidden>
+            <button type="button" class="btn btn-small companion-icon" data-action="companion-toggle" title="Companion status" aria-label="Companion status">○</button>
+            <div class="dropdown-menu align-right open-up companion-flyout"></div>
+        </span>
+    </footer>
+</div>
+{{if not .EditMode}}{{block "aside" .}}{{end}}{{end}}
+{{end}}
+
+{{/* Response to boosted navigation and history restores (hx.js swaps it into
+.shell): the title, the page actions out-of-band, and the shell's content. */}}
+{{define "partial"}}<title>{{.Title}}</title>
+{{template "page-actions" .}}
+{{template "shell" .}}{{end}}

assets/modal.js

@@ -1,120 +1,111 @@
+// One modal at a time, from either of two sources sharing the same chrome
+// (backdrop click, Escape, drag by the header, focus restore):
+//   - openModal(opts) builds a modal from JS;
+//   - server-rendered dialogs (assets/page/dialogs.html) that htmx swaps into
+//     #modal-host. Their forms post themselves; a [data-modal-close] element
+//     closes them.
 (function () {
-    var backdrop = null;
-    var modal = null;
-    var titleEl = null;
-    var bodyEl = null;
-    var cancelBtn = null;
-    var confirmBtn = null;
-    var footerEl = null;
-    var prevFocus = null;
-    var currentOpts = null;
-    var onKeydown = null;
+    var current = null; // { backdrop, prevFocus, onKeydown }
+    var drag = null;    // { modal, startX, startY, originX, originY }
 
-    function build() {
-        backdrop = document.createElement('div');
+    // show mounts backdrop (whose child is the .modal) into parent and makes
+    // it the current modal. onKeydown handles keys beyond Escape.
+    function show(backdrop, parent, prevFocus, onKeydown) {
+        var modal = backdrop.querySelector('.modal');
+        var header = modal.querySelector('.panel-header');
+        function onDown(e) { startDrag(e, modal); }
+        header.addEventListener('mousedown', onDown);
+        header.addEventListener('touchstart', onDown, { passive: false });
+        backdrop.addEventListener('mousedown', function (e) {
+            if (e.target === backdrop) close();
+        });
+        backdrop.addEventListener('click', function (e) {
+            if (e.target.closest('[data-modal-close]')) close();
+        });
+
+        var keydown = function (e) {
+            if (e.key === 'Escape') {
+                e.preventDefault();
+                close();
+                return;
+            }
+            if (onKeydown) onKeydown(e);
+        };
+        document.addEventListener('keydown', keydown);
+        current = { backdrop: backdrop, prevFocus: prevFocus, onKeydown: keydown };
+        if (backdrop.parentNode !== parent) parent.appendChild(backdrop);
+    }
+
+    // Dragging switches the modal to fixed positioning so flexbox alignment
+    // doesn't fight us.
+    function startDrag(e, modal) {
+        if (e.button !== undefined && e.button !== 0) return;
+        var pt = e.touches ? e.touches[0] : e;
+        var rect = modal.getBoundingClientRect();
+        modal.classList.add('is-dragged');
+        modal.style.position = 'fixed';
+        modal.style.left = rect.left + 'px';
+        modal.style.top = rect.top + 'px';
+        drag = { modal: modal, startX: pt.clientX, startY: pt.clientY, originX: rect.left, originY: rect.top };
+        e.preventDefault();
+    }
+
+    function onMove(e) {
+        if (!drag) return;
+        var pt = e.touches ? e.touches[0] : e;
+        var m = drag.modal;
+        var maxX = window.innerWidth - m.offsetWidth;
+        var maxY = window.innerHeight - m.offsetHeight;
+        m.style.left = Math.max(0, Math.min(maxX, drag.originX + pt.clientX - drag.startX)) + 'px';
+        m.style.top = Math.max(0, Math.min(maxY, drag.originY + pt.clientY - drag.startY)) + 'px';
+    }
+
+    function onUp() { drag = null; }
+
+    document.addEventListener('mousemove', onMove);
+    document.addEventListener('touchmove', onMove, { passive: false });
+    document.addEventListener('mouseup', onUp);
+    document.addEventListener('touchend', onUp);
+
+    // detach tears down the current modal and returns the element that had
+    // focus before it opened. keepDOM leaves the backdrop in place for a swap
+    // about to replace it: htmx must still find the element that issued the
+    // request in the document.
+    function detach(keepDOM) {
+        if (!current) return null;
+        var c = current;
+        current = null;
+        drag = null;
+        document.removeEventListener('keydown', c.onKeydown);
+        if (!keepDOM && c.backdrop.parentNode) c.backdrop.parentNode.removeChild(c.backdrop);
+        return c.prevFocus;
+    }
+
+    function close() {
+        var toRestore = detach();
+        if (toRestore && toRestore.focus) {
+            try { toRestore.focus(); } catch (e) {}
+        }
+    }
+
+    function open(opts) {
+        var prevFocus = current ? detach() : document.activeElement;
+
+        var backdrop = document.createElement('div');
         backdrop.className = 'modal-backdrop';
-
-        modal = document.createElement('div');
+        var modal = document.createElement('div');
         modal.className = 'modal panel panel-floating';
         modal.setAttribute('role', 'dialog');
         modal.setAttribute('aria-modal', 'true');
 
         var header = document.createElement('div');
         header.className = 'panel-header';
-        titleEl = document.createElement('span');
+        var titleEl = document.createElement('span');
+        titleEl.textContent = opts.title || '';
         header.appendChild(titleEl);
 
-        bodyEl = document.createElement('div');
+        var bodyEl = document.createElement('div');
         bodyEl.className = 'panel-body';
-
-        footerEl = document.createElement('div');
-        footerEl.className = 'panel-footer';
-
-        cancelBtn = document.createElement('button');
-        cancelBtn.type = 'button';
-        confirmBtn = document.createElement('button');
-        confirmBtn.type = 'button';
-
-        modal.appendChild(header);
-        modal.appendChild(bodyEl);
-        modal.appendChild(footerEl);
-        backdrop.appendChild(modal);
-
-        backdrop.addEventListener('mousedown', function (e) {
-            if (e.target === backdrop) close();
-        });
-        wireDrag(header);
-        cancelBtn.addEventListener('click', close);
-        confirmBtn.addEventListener('click', function () {
-            if (confirmBtn.disabled) return;
-            if (currentOpts && currentOpts.confirm && currentOpts.confirm.onConfirm) {
-                currentOpts.confirm.onConfirm();
-            }
-        });
-    }
-
-    // wireDrag makes the modal draggable by `handle`. Dragging switches the
-    // modal to fixed positioning so flexbox alignment doesn't fight us.
-    function wireDrag(handle) {
-        var dragging = false;
-        var startX, startY, originX, originY;
-
-        function onDown(e) {
-            if (e.button !== undefined && e.button !== 0) return;
-            var pt = e.touches ? e.touches[0] : e;
-            var rect = modal.getBoundingClientRect();
-            modal.classList.add('is-dragged');
-            modal.style.position = 'fixed';
-            modal.style.left = rect.left + 'px';
-            modal.style.top = rect.top + 'px';
-            dragging = true;
-            startX = pt.clientX;
-            startY = pt.clientY;
-            originX = rect.left;
-            originY = rect.top;
-            e.preventDefault();
-        }
-
-        function onMove(e) {
-            if (!dragging) return;
-            var pt = e.touches ? e.touches[0] : e;
-            var dx = pt.clientX - startX;
-            var dy = pt.clientY - startY;
-            var w = modal.offsetWidth;
-            var h = modal.offsetHeight;
-            var maxX = window.innerWidth - w;
-            var maxY = window.innerHeight - h;
-            var x = Math.max(0, Math.min(maxX, originX + dx));
-            var y = Math.max(0, Math.min(maxY, originY + dy));
-            modal.style.left = x + 'px';
-            modal.style.top = y + 'px';
-        }
-
-        function onUp() { dragging = false; }
-
-        handle.addEventListener('mousedown', onDown);
-        handle.addEventListener('touchstart', onDown, { passive: false });
-        document.addEventListener('mousemove', onMove);
-        document.addEventListener('touchmove', onMove, { passive: false });
-        document.addEventListener('mouseup', onUp);
-        document.addEventListener('touchend', onUp);
-    }
-
-    function open(opts) {
-        if (backdrop && backdrop.parentNode) close();
-        if (!backdrop) build();
-
-        currentOpts = opts;
-        prevFocus = document.activeElement;
-
-        modal.classList.remove('is-dragged');
-        modal.style.position = '';
-        modal.style.left = '';
-        modal.style.top = '';
-
-        titleEl.textContent = opts.title || '';
-
-        bodyEl.textContent = '';
         if (opts.body instanceof Node) {
             bodyEl.appendChild(opts.body);
         } else if (typeof opts.body === 'string') {
@@ -124,14 +115,24 @@
         var confirmOpts = opts.confirm || {};
         var cancelOpts = opts.cancel || {};
 
+        var confirmBtn = document.createElement('button');
+        confirmBtn.type = 'button';
         confirmBtn.textContent = confirmOpts.label || 'OK';
         confirmBtn.className = 'btn' + (confirmOpts.danger ? ' danger' : '');
         confirmBtn.disabled = !!confirmOpts.initiallyDisabled;
+        confirmBtn.addEventListener('click', function () {
+            if (confirmBtn.disabled) return;
+            if (confirmOpts.onConfirm) confirmOpts.onConfirm();
+        });
 
+        var cancelBtn = document.createElement('button');
+        cancelBtn.type = 'button';
         cancelBtn.textContent = cancelOpts.label || 'CANCEL';
         cancelBtn.className = 'btn';
+        cancelBtn.setAttribute('data-modal-close', '');
 
-        footerEl.textContent = '';
+        var footerEl = document.createElement('div');
+        footerEl.className = 'panel-footer';
         if (opts.swapButtons) {
             footerEl.appendChild(confirmBtn);
             footerEl.appendChild(cancelBtn);
@@ -140,7 +141,20 @@
             footerEl.appendChild(confirmBtn);
         }
 
-        document.body.appendChild(backdrop);
+        modal.appendChild(header);
+        modal.appendChild(bodyEl);
+        modal.appendChild(footerEl);
+        backdrop.appendChild(modal);
+
+        var enterConfirms = confirmOpts.enterConfirms !== false;
+        show(backdrop, document.body, prevFocus, function (e) {
+            if (e.key === 'Enter' && enterConfirms) {
+                var tag = (e.target && e.target.tagName) || '';
+                if (tag === 'TEXTAREA') return;
+                e.preventDefault();
+                if (!confirmBtn.disabled) confirmBtn.click();
+            }
+        });
 
         setTimeout(function () {
             if (cancelOpts.autofocus) {
@@ -156,22 +170,6 @@
             }
         }, 0);
 
-        var enterConfirms = confirmOpts.enterConfirms !== false;
-        onKeydown = function (e) {
-            if (e.key === 'Escape') {
-                e.preventDefault();
-                close();
-                return;
-            }
-            if (e.key === 'Enter' && enterConfirms) {
-                var tag = (e.target && e.target.tagName) || '';
-                if (tag === 'TEXTAREA') return;
-                e.preventDefault();
-                if (!confirmBtn.disabled) confirmBtn.click();
-            }
-        };
-        document.addEventListener('keydown', onKeydown);
-
         return {
             close: close,
             setConfirmDisabled: function (d) { confirmBtn.disabled = !!d; },
@@ -179,20 +177,30 @@
         };
     }
 
-    function close() {
-        if (!backdrop || !backdrop.parentNode) return;
-        if (onKeydown) {
-            document.removeEventListener('keydown', onKeydown);
-            onKeydown = null;
-        }
-        backdrop.parentNode.removeChild(backdrop);
-        currentOpts = null;
-        var toRestore = prevFocus;
-        prevFocus = null;
-        if (toRestore && toRestore.focus) {
-            try { toRestore.focus(); } catch (e) {}
-        }
+    // Server-rendered dialogs. A swap into #modal-host replaces whatever modal
+    // is open (e.g. the merge step replacing the move dialog); focus returns
+    // to where it was before the first one opened.
+    var hostPrevFocus = null;
+    // History restores swap without event details; they never target the host.
+    function isHost(e) {
+        return !!(e.detail && e.detail.target && e.detail.target.id === 'modal-host');
     }
+    document.addEventListener('htmx:beforeSwap', function (e) {
+        if (!isHost(e)) return;
+        hostPrevFocus = current ? detach(true) : document.activeElement;
+    });
+    document.addEventListener('htmx:afterSwap', function (e) {
+        if (!isHost(e)) return;
+        var host = e.detail.target;
+        var backdrop = host.querySelector('.modal-backdrop');
+        if (!backdrop) return;
+        show(backdrop, host, hostPrevFocus);
+        var f = backdrop.querySelector('[autofocus]') || backdrop.querySelector('input:not([type=hidden])');
+        if (f) {
+            f.focus();
+            if (f.select) f.select();
+        }
+    });
 
     window.openModal = open;
     window.closeModal = close;

assets/page/actions.js

@@ -3,40 +3,6 @@ function encodePickedPath(p) {
     return '/' + p.replace(/^\/+/, '').split('/').map(encodeURIComponent).join('/');
 }
 
-// postReplace POSTs to action with the optional form body, then loads target
-// into the current history entry — so the action and its result occupy one
-// entry instead of two, and back-navigation skips past the stale pre-mutation
-// snapshot in bfcache. body may be null for empty POSTs.
-//
-// We can't just call window.location.replace(target): when target differs from
-// the current URL only by fragment, the browser updates the URL bar without
-// re-fetching, so a server-side mutation wouldn't be reflected. Instead,
-// rewrite the current entry's URL via history.replaceState, then reload — the
-// reload always re-fetches and preserves the (new) URL including its fragment.
-function navigateReplace(target) {
-    window.history.replaceState(null, '', target);
-    window.location.reload();
-}
-
-function postReplace(action, body, target) {
-    var init = { method: 'POST', redirect: 'manual' };
-    if (body) {
-        init.headers = { 'Content-Type': 'application/x-www-form-urlencoded' };
-        init.body = body;
-    }
-    fetch(action, init).then(function (res) {
-        if (res.type === 'opaqueredirect' || res.ok) {
-            navigateReplace(target);
-            return;
-        }
-        return res.text().then(function (msg) {
-            alert(msg || ('Request failed (' + res.status + ')'));
-        });
-    }).catch(function () {
-        alert('Network error');
-    });
-}
-
 function promptPageName(title, initial, confirmLabel, onName) {
     var input = document.createElement('input');
     input.type = 'text';
@@ -75,45 +41,10 @@ function newPage() {
     });
 }
 
-// submitMove POSTs a move and navigates on success. When the server reports
-// the destination folder already exists but can be merged (the source carries
-// a page and the destination has none), it asks the user to confirm and
-// retries the same move with &merge=1.
-function submitMove(action, target) {
-    fetch(action, { method: 'POST', redirect: 'manual' }).then(function (res) {
-        if (res.type === 'opaqueredirect' || res.ok) {
-            navigateReplace(target);
-            return;
-        }
-        if (res.status === 409 && res.headers.get('X-Merge-Available') === '1') {
-            openModal({
-                title: 'Merge folders?',
-                body: 'The destination folder already exists but has no page of its own. Merge this page and its contents into it?',
-                confirm: {
-                    label: 'MERGE',
-                    onConfirm: function () {
-                        closeModal();
-                        submitMove(action + '&merge=1', target);
-                    }
-                }
-            });
-            return;
-        }
-        return res.text().then(function (msg) {
-            alert(msg || ('Request failed (' + res.status + ')'));
-        });
-    }).catch(function () {
-        alert('Network error');
-    });
-}
-
 function movePage() {
     var current = decodeURIComponent(window.location.pathname).replace(/\/+$/, '');
     if (!current) return;
-    var segs = current.split('/').filter(Boolean);
-    var currentName = segs[segs.length - 1] || '';
-    var parent = '/' + segs.slice(0, -1).join('/');
-    if (parent === '/') parent = '/';
+    var parent = '/' + current.split('/').filter(Boolean).slice(0, -1).join('/');
 
     openTreePicker({
         title: 'Move — new parent?',
@@ -123,53 +54,13 @@ function movePage() {
         hideFiles: true,
         confirmLabel: 'NEXT',
         onSelect: function (newParent) {
-            var input = document.createElement('input');
-            input.type = 'text';
-            input.className = 'input';
-            input.placeholder = 'Page name';
-            input.value = currentName;
-
-            openModal({
-                title: 'Move — new name?',
-                body: input,
-                confirm: {
-                    label: 'MOVE',
-                    onConfirm: function () {
-                        var name = input.value.trim();
-                        if (!name) return;
-                        var dest = (newParent === '/' ? '' : newParent) + '/' + name;
-                        var action = window.location.pathname + '?move=' +
-                            encodeURIComponent(dest);
-                        var target = encodePickedPath(dest) + '/';
-                        closeModal();
-                        submitMove(action, target);
-                    }
-                }
+            // The server renders the name step and handles what follows
+            // (merge confirmation, errors, redirect).
+            closeModal();
+            htmx.ajax('GET', window.location.pathname + '?dialog=move', {
+                target: '#modal-host',
+                values: { parent: newParent }
             });
         }
     });
 }
-
-function deletePage() {
-    var decodedPath = decodeURIComponent(window.location.pathname);
-
-    openModal({
-        title: 'Delete page',
-        body: 'Delete ' + decodedPath + ' and everything inside it?',
-        confirm: {
-            label: 'DELETE',
-            danger: true,
-            enterConfirms: false,
-            onConfirm: function () {
-                var p = window.location.pathname.replace(/\/+$/, '');
-                var idx = p.lastIndexOf('/');
-                var parent = idx > 0 ? p.substring(0, idx + 1) : '/';
-                closeModal();
-                postReplace(window.location.pathname + '?delete=1', null, parent);
-            }
-        },
-        cancel: { autofocus: true },
-        swapButtons: true
-    });
-}
-

assets/page/contents.js

@@ -1,15 +1,21 @@
-document.addEventListener("DOMContentLoaded", function () {
-  var aside = document.querySelector("aside.sidebar");
-  var specials = document.querySelector(".actions-special");
-  if (!aside || !aside.children.length || !specials) return;
+// Runs on DOMContentLoaded for a full page load, and right away when this
+// script arrives with a boosted navigation (the document is loaded then).
+(function () {
+  function run() {
+    var aside = document.querySelector("aside.sidebar");
+    var specials = document.querySelector(".actions-special");
+    if (!aside || !aside.children.length || !specials) return;
 
-  var item = document.createElement("button");
-  item.type = "button";
-  item.className = "btn btn-block";
-  item.title = "Contents";
-  item.textContent = "CONTENTS";
-  item.addEventListener("click", function () {
-    if (typeof openOverlay === "function") openOverlay(aside);
-  });
-  specials.appendChild(item);
-});
+    var item = document.createElement("button");
+    item.type = "button";
+    item.className = "btn btn-block";
+    item.title = "Contents";
+    item.textContent = "CONTENTS";
+    item.addEventListener("click", function () {
+      if (typeof openOverlay === "function") openOverlay(aside);
+    });
+    specials.appendChild(item);
+  }
+  if (document.readyState === "loading") document.addEventListener("DOMContentLoaded", run);
+  else run();
+})();

assets/page/dialogs.html

@@ -0,0 +1,80 @@
+{{/* Server-rendered dialogs, fetched with ?dialog=<name> and swapped into
+#modal-host by htmx; modal.js supplies the chrome (backdrop, Escape, drag,
+focus). Each dialog is a form that posts the action it offers, so the client
+never builds action URLs itself. Responses to those posts either redirect
+(HX-Redirect), replace the dialog with the next step (e.g. the merge
+confirmation), or fail with a plain-text error. */}}
+
+{{define "delete"}}<div class="modal-backdrop">
+<form class="modal panel panel-floating" role="dialog" aria-modal="true" aria-labelledby="modal-title" hx-post="?delete=1" hx-target="#modal-host">
+<div class="panel-header"><span id="modal-title">Delete page</span></div>
+<div class="panel-body">Delete {{.Path}} and everything inside it?</div>
+<div class="panel-footer">
+<button class="btn danger" type="submit">DELETE</button>
+<button class="btn" type="button" data-modal-close autofocus>CANCEL</button>
+</div>
+</form>
+</div>{{end}}
+
+{{define "move"}}<div class="modal-backdrop">
+<form class="modal panel panel-floating" role="dialog" aria-modal="true" aria-labelledby="modal-title" hx-post="?move" hx-target="#modal-host">
+<div class="panel-header"><span id="modal-title">Move — new name?</span></div>
+<div class="panel-body">
+<input type="hidden" name="parent" value="{{.Parent}}" />
+<input class="input" type="text" name="name" value="{{.Name}}" placeholder="Page name" required autofocus />
+</div>
+<div class="panel-footer">
+<button class="btn" type="button" data-modal-close>CANCEL</button>
+<button class="btn" type="submit">MOVE</button>
+</div>
+</form>
+</div>{{end}}
+
+{{define "merge"}}<div class="modal-backdrop">
+<form class="modal panel panel-floating" role="dialog" aria-modal="true" aria-labelledby="modal-title" hx-post="?move" hx-target="#modal-host">
+<div class="panel-header"><span id="modal-title">Merge folders?</span></div>
+<div class="panel-body">
+The destination folder already exists but has no page of its own. Merge this page and its contents into it?
+<input type="hidden" name="move" value="{{.Dest}}" />
+<input type="hidden" name="merge" value="1" />
+</div>
+<div class="panel-footer">
+<button class="btn" type="button" data-modal-close>CANCEL</button>
+<button class="btn" type="submit" autofocus>MERGE</button>
+</div>
+</form>
+</div>{{end}}
+
+{{define "view"}}<div class="modal-backdrop">
+<form class="modal panel panel-floating" role="dialog" aria-modal="true" aria-labelledby="modal-title" hx-post="?settings" hx-target="#modal-host">
+<div class="panel-header"><span id="modal-title">View settings</span></div>
+<div class="panel-body col">
+<fieldset class="col gap-1">
+<legend class="caption">View style</legend>
+<div class="row gap-1 segmented">
+<label class="btn"><input type="radio" name="view" value="list"{{if eq .View "list"}} checked{{end}} />List</label>
+<label class="btn"><input type="radio" name="view" value="thumbnail"{{if eq .View "thumbnail"}} checked{{end}} />Thumbnail</label>
+</div>
+</fieldset>
+<label class="col gap-1">
+<span class="caption">Sort by</span>
+<select class="input" name="sort">
+<option value="name"{{if eq .Sort "name"}} selected{{end}}>Name</option>
+<option value="modified"{{if eq .Sort "modified"}} selected{{end}}>Modified</option>
+<option value="size"{{if eq .Sort "size"}} selected{{end}}>Size</option>
+</select>
+</label>
+<fieldset class="col gap-1">
+<legend class="caption">Order</legend>
+<div class="row gap-1 segmented">
+<label class="btn"><input type="radio" name="order" value="asc"{{if eq .Order "asc"}} checked{{end}} />Asc</label>
+<label class="btn"><input type="radio" name="order" value="desc"{{if eq .Order "desc"}} checked{{end}} />Desc</label>
+</div>
+</fieldset>
+</div>
+<div class="panel-footer">
+<button class="btn" type="button" data-modal-close>CANCEL</button>
+<button class="btn" type="submit" autofocus>SAVE</button>
+</div>
+</form>
+</div>{{end}}

assets/page/main.html

@@ -1,11 +1,9 @@
-{{define "headScripts"}}<script src="{{asset "page/actions.js"}}"></script>{{end}}
-
 {{define "headerActions"}}{{if .CanEdit}}
 <button class="btn btn-block" onclick="newPage()" title="New page (N)"><span class="btn-icon">{{icon "new"}}</span><span class="btn-label">NEW</span></button>
 <button class="btn btn-block" data-companion-reveal hidden title="Reveal in file manager"><span class="btn-icon">{{icon "reveal"}}</span><span class="btn-label">REVEAL</span></button>
 {{if not .IsRoot}}
 <button class="btn btn-block" onclick="movePage()" title="Move page (M)"><span class="btn-icon">{{icon "move"}}</span><span class="btn-label">MOVE</span></button>
-<button class="btn btn-block danger" onclick="deletePage()" title="Delete page"><span class="btn-icon">{{icon "delete"}}</span><span class="btn-label">DELETE</span></button>
+<button class="btn btn-block danger" hx-get="?dialog=delete" hx-target="#modal-host" title="Delete page"><span class="btn-icon">{{icon "delete"}}</span><span class="btn-label">DELETE</span></button>
 {{end}}
 <a class="btn btn-block" href="?edit" title="Edit page (E)"><span class="btn-icon">{{icon "edit"}}</span><span class="btn-label">EDIT</span></a>
 {{end}}{{end}}
@@ -21,7 +19,7 @@
 <p class="empty">{{if .Entries}}No page{{else}}Empty folder{{end}} — <a href="?edit">[CREATE]</a></p>
 {{end}}
 {{if .Entries}}
-<h2 id="files">Files <button class="btn btn-small" data-companion-reveal hidden title="Open folder in file manager">open</button>{{if .CanEdit}} <button class="btn btn-small" id="view-settings-btn" onclick="openViewSettings()" title="View &amp; sorting" data-view="{{.View}}" data-sort="{{.Sort}}" data-order="{{.Order}}">view</button>{{end}}</h2>
+<h2 id="files">Files <button class="btn btn-small" data-companion-reveal hidden title="Open folder in file manager">open</button>{{if .CanEdit}} <button class="btn btn-small" hx-get="?dialog=view" hx-target="#modal-host" title="View &amp; sorting">view</button>{{end}}</h2>
 {{if eq .View "thumbnail"}}
 <div class="thumb-grid">
     {{range .Entries}}
@@ -44,12 +42,10 @@
     </tbody>
 </table>
 {{end}}
-{{if .CanEdit}}<script src="{{asset "page/view-settings.js"}}"></script>{{end}}
 {{end}}
 {{if or .Content .SpecialContent}}
 <script src="{{asset "page/content.js"}}"></script>
 {{if not .SuppressTOC}}<script src="{{asset "page/toc.js"}}"></script>{{end}}
-<script src="{{asset "page/tasks.js"}}"></script>
 {{end}}
 {{if .Content}}
 <script src="{{asset "page/sections.js"}}"></script>

assets/page/tasks.js

@@ -1,24 +0,0 @@
-(function () {
-    document.querySelectorAll('input.task-checkbox[data-task-index]').forEach(function (cb) {
-        cb.addEventListener('change', function () {
-            var idx = cb.dataset.taskIndex;
-            var checked = cb.checked;
-            cb.disabled = true;
-            fetch(window.location.pathname + '?toggle=' + idx, {
-                method: 'POST',
-                headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
-                body: 'checked=' + checked
-            }).then(function (res) {
-                if (!res.ok) {
-                    cb.checked = !checked;
-                    alert('Failed to save task state (' + res.status + ')');
-                }
-            }).catch(function () {
-                cb.checked = !checked;
-                alert('Failed to save task state');
-            }).finally(function () {
-                cb.disabled = false;
-            });
-        });
-    });
-})();

assets/page/toc.js

@@ -1,32 +1,38 @@
-document.addEventListener("DOMContentLoaded", function () {
-  var content = document.querySelector("main");
-  if (!content) return;
+// Runs on DOMContentLoaded for a full page load, and right away when this
+// script arrives with a boosted navigation (the document is loaded then).
+(function () {
+  function run() {
+    var content = document.querySelector("main");
+    if (!content) return;
 
-  var headings = content.querySelectorAll("h2, h3, h4");
-  if (headings.length < 2) return;
+    var headings = content.querySelectorAll("h2, h3, h4");
+    if (headings.length < 2) return;
 
-  var nav = document.createElement("nav");
-  nav.className = "toc panel";
+    var nav = document.createElement("nav");
+    nav.className = "toc panel";
 
-  var header = document.createElement("div");
-  header.className = "panel-header";
-  header.textContent = "Contents";
-  nav.appendChild(header);
+    var header = document.createElement("div");
+    header.className = "panel-header";
+    header.textContent = "Contents";
+    nav.appendChild(header);
 
-  var list = document.createElement("ul");
-  headings.forEach(function (h) {
-    if (!h.id) return;
-    var li = document.createElement("li");
-    li.className = "toc-" + h.tagName.toLowerCase();
-    var a = document.createElement("a");
-    a.href = "#" + h.id;
-    var clone = h.cloneNode(true);
-    clone.querySelectorAll(".btn, .muted, .dropdown").forEach(function (el) { el.remove(); });
-    a.textContent = clone.textContent.trim();
-    li.appendChild(a);
-    list.appendChild(li);
-  });
-  nav.appendChild(list);
+    var list = document.createElement("ul");
+    headings.forEach(function (h) {
+      if (!h.id) return;
+      var li = document.createElement("li");
+      li.className = "toc-" + h.tagName.toLowerCase();
+      var a = document.createElement("a");
+      a.href = "#" + h.id;
+      var clone = h.cloneNode(true);
+      clone.querySelectorAll(".btn, .muted, .dropdown").forEach(function (el) { el.remove(); });
+      a.textContent = clone.textContent.trim();
+      li.appendChild(a);
+      list.appendChild(li);
+    });
+    nav.appendChild(list);
 
-  content.insertBefore(nav, content.firstChild);
-});
+    content.insertBefore(nav, content.firstChild);
+  }
+  if (document.readyState === "loading") document.addEventListener("DOMContentLoaded", run);
+  else run();
+})();

assets/page/view-settings.js

@@ -1,85 +0,0 @@
-// View-settings modal: lets the user pick the folder listing's view style,
-// sort key, and order, then persists them by POSTing to the folder with
-// ?settings. Reuses openModal/closeModal and postReplace from page/actions.js.
-function openViewSettings() {
-    var btn = document.getElementById('view-settings-btn');
-    var state = {
-        view: (btn && btn.dataset.view) || 'list',
-        sort: (btn && btn.dataset.sort) || 'name',
-        order: (btn && btn.dataset.order) || 'asc'
-    };
-
-    // segmented builds a row of mutually-exclusive .btn toggles bound to a
-    // single state key, marking the current choice with .is-active.
-    function segmented(key, options) {
-        var wrap = document.createElement('div');
-        wrap.className = 'row gap-1';
-        options.forEach(function (opt) {
-            var b = document.createElement('button');
-            b.type = 'button';
-            b.className = 'btn';
-            b.textContent = opt.label;
-            if (state[key] === opt.value) b.classList.add('is-active');
-            b.addEventListener('click', function () {
-                state[key] = opt.value;
-                wrap.querySelectorAll('button').forEach(function (x) {
-                    x.classList.remove('is-active');
-                });
-                b.classList.add('is-active');
-            });
-            wrap.appendChild(b);
-        });
-        return wrap;
-    }
-
-    function field(labelText, control) {
-        var row = document.createElement('div');
-        row.className = 'col gap-1';
-        var label = document.createElement('span');
-        label.className = 'caption';
-        label.textContent = labelText;
-        row.appendChild(label);
-        row.appendChild(control);
-        return row;
-    }
-
-    var sortSelect = document.createElement('select');
-    sortSelect.className = 'input';
-    [['name', 'Name'], ['modified', 'Modified'], ['size', 'Size']].forEach(function (o) {
-        var opt = document.createElement('option');
-        opt.value = o[0];
-        opt.textContent = o[1];
-        if (state.sort === o[0]) opt.selected = true;
-        sortSelect.appendChild(opt);
-    });
-    sortSelect.addEventListener('change', function () { state.sort = sortSelect.value; });
-
-    var body = document.createElement('div');
-    body.className = 'col';
-    body.appendChild(field('View style', segmented('view', [
-        { value: 'list', label: 'List' },
-        { value: 'thumbnail', label: 'Thumbnail' }
-    ])));
-    body.appendChild(field('Sort by', sortSelect));
-    body.appendChild(field('Order', segmented('order', [
-        { value: 'asc', label: 'Asc' },
-        { value: 'desc', label: 'Desc' }
-    ])));
-
-    openModal({
-        title: 'View settings',
-        body: body,
-        confirm: {
-            label: 'SAVE',
-            onConfirm: function () {
-                var action = window.location.pathname + '?settings';
-                var formBody = 'view=' + encodeURIComponent(state.view) +
-                    '&sort=' + encodeURIComponent(state.sort) +
-                    '&order=' + encodeURIComponent(state.order);
-                var target = window.location.pathname;
-                closeModal();
-                postReplace(action, formBody, target);
-            }
-        }
-    });
-}

assets/scroll-sync.js

@@ -45,17 +45,22 @@
     }
 
     // Reading mode: keep the latest scroll fraction recorded (throttled to one
-    // write per frame) so it is ready the moment the editor opens.
+    // write per frame) so it is ready the moment the editor opens. Boosted
+    // navigation replaces .center and changes the page without a reload, so
+    // listen on document and resolve both when writing.
     var pending = false;
-    center.addEventListener('scroll', function () {
-        if (pending) return;
+    document.addEventListener('scroll', function (e) {
+        if (pending || !e.target.classList || !e.target.classList.contains('center')) return;
         pending = true;
         requestAnimationFrame(function () {
             pending = false;
+            center = document.querySelector('.center');
+            if (!center) return;
             var m = maxScroll();
             try {
-                sessionStorage.setItem(key, JSON.stringify({ f: m > 0 ? center.scrollTop / m : 0, t: Date.now() }));
+                sessionStorage.setItem('scrollsync:' + location.pathname,
+                    JSON.stringify({ f: m > 0 ? center.scrollTop / m : 0, t: Date.now() }));
             } catch (e) {}
         });
-    }, { passive: true });
+    }, { capture: true, passive: true });
 })();

assets/search-suggest.js

@@ -1,63 +1,18 @@
 // search-suggest.js — instant typeahead dropdown.
 //
 // Exposes window.attachSuggestions(inputEl, opts) used by both the header
-// search box and the editor's "Insert link" modal. Owns: debounced fetching,
-// request ordering, DOM creation, keyboard handling, open/close lifecycle.
+// search box and the editor's "Insert link" modal. Fetching is htmx: the input
+// requests /_search as you type (debounced; a newer request replaces an
+// in-flight one) and the server renders the rows (assets/search/suggest.html).
+// This file owns the dropdown's open/close lifecycle and keyboard handling.
 //
 // opts:
-//   onPick(result)        — called when the user selects a row
-//   onShowAll(query)      — optional; called when the footer row activates
+//   onPick({name})        — optional; called when the user selects a row.
+//                           Without it rows are plain links and navigate.
 //   showFooter (bool)     — show the "Show all N matches" footer row
 //   container (Element)   — optional parent (defaults to inputEl.parentNode)
 (function () {
-    var DEBOUNCE_MS = 100;
-    var MIN_QUERY_LEN = 2;
-
-    function escapeHTML(s) {
-        return String(s)
-            .replace(/&/g, '&')
-            .replace(/</g, '&lt;')
-            .replace(/>/g, '&gt;')
-            .replace(/"/g, '&quot;');
-    }
-
-    function tokenize(s) {
-        return s.toLowerCase().split(/[^\p{L}\p{N}]+/u).filter(Boolean);
-    }
-
-    // highlight bolds the substring spans in `name` that match any of the
-    // query tokens (case-insensitive). Overlapping/adjacent spans merge.
-    // Returns a safe HTML string.
-    function highlight(name, tokens) {
-        if (!tokens.length) return escapeHTML(name);
-        var lower = name.toLowerCase();
-        var spans = [];
-        tokens.forEach(function (t) {
-            if (!t) return;
-            var idx = lower.indexOf(t);
-            if (idx >= 0) spans.push([idx, idx + t.length]);
-        });
-        if (!spans.length) return escapeHTML(name);
-        spans.sort(function (a, b) { return a[0] - b[0]; });
-        var merged = [spans[0].slice()];
-        for (var i = 1; i < spans.length; i++) {
-            var last = merged[merged.length - 1];
-            if (spans[i][0] <= last[1]) {
-                last[1] = Math.max(last[1], spans[i][1]);
-            } else {
-                merged.push(spans[i].slice());
-            }
-        }
-        var out = '';
-        var cursor = 0;
-        merged.forEach(function (sp) {
-            out += escapeHTML(name.slice(cursor, sp[0]));
-            out += '<strong>' + escapeHTML(name.slice(sp[0], sp[1])) + '</strong>';
-            cursor = sp[1];
-        });
-        out += escapeHTML(name.slice(cursor));
-        return out;
-    }
+    var seq = 0;
 
     function attachSuggestions(inputEl, opts) {
         if (!inputEl) return;
@@ -68,237 +23,116 @@
 
         var dropdown = document.createElement('div');
         dropdown.className = 'suggest-dropdown';
+        dropdown.id = 'suggest-' + (++seq);
         host.appendChild(dropdown);
 
-        function makeRow(cls, tabbable) {
-            var tr = document.createElement('tr');
-            tr.className = cls;
-            if (tabbable) tr.setAttribute('tabindex', '0');
-            var td = document.createElement('td');
-            tr.appendChild(td);
-            return { tr: tr, td: td };
+        // htmx sends the input's value under its name.
+        if (!inputEl.name) inputEl.name = 'q';
+        inputEl.setAttribute('hx-get', '/_search' + (opts.showFooter ? '?footer' : ''));
+        inputEl.setAttribute('hx-trigger', 'input changed delay:100ms');
+        inputEl.setAttribute('hx-sync', 'this:replace');
+        inputEl.setAttribute('hx-target', '#' + dropdown.id);
+        htmx.process(inputEl);
+
+        var activeIdx = -1;
+
+        function rows() {
+            return dropdown.querySelectorAll('.suggest-row');
         }
 
-        var state = {
-            results: [],
-            total: 0,
-            query: '',
-            activeIdx: -1,
-            open: false,
-            reqSeq: 0,
-            debounceTimer: null,
-            blurTimer: null,
-        };
-
-        function rowCount() {
-            var n = state.results.length;
-            if (state.results.length === 0 && state.query.length >= MIN_QUERY_LEN) {
-                return 0; // "no matches" row is non-interactive
-            }
-            if (opts.showFooter && state.total > state.results.length) n += 1;
-            return n;
-        }
-
-        function isFooterIdx(idx) {
-            return opts.showFooter
-                && state.total > state.results.length
-                && idx === state.results.length;
-        }
-
-        function render() {
-            dropdown.textContent = '';
-            if (!state.open) {
-                dropdown.classList.remove('is-open');
-                return;
-            }
-            var table = document.createElement('table');
-            table.className = 'data-table';
-            var tbody = document.createElement('tbody');
-            table.appendChild(tbody);
-
-            var tokens = tokenize(state.query);
-            if (state.results.length === 0) {
-                var empty = makeRow('is-empty', false);
-                empty.td.textContent = 'No matches';
-                tbody.appendChild(empty.tr);
-            } else {
-                state.results.forEach(function (r, i) {
-                    var row = makeRow('suggest-row', true);
-                    row.tr.setAttribute('data-idx', String(i));
-                    var nameEl = document.createElement('span');
-                    nameEl.className = 'suggest-name';
-                    nameEl.innerHTML = highlight(r.name, tokens);
-                    var pathEl = document.createElement('span');
-                    pathEl.className = 'suggest-path';
-                    pathEl.textContent = '/' + r.path;
-                    row.td.appendChild(nameEl);
-                    row.td.appendChild(pathEl);
-                    if (i === state.activeIdx) row.tr.classList.add('is-active');
-                    row.tr.addEventListener('mousedown', function (e) {
-                        // mousedown (not click) so the input doesn't blur-close
-                        // the dropdown before the pick handler fires.
-                        e.preventDefault();
-                        pick(i);
-                    });
-                    tbody.appendChild(row.tr);
-                });
-                if (opts.showFooter && state.total > state.results.length) {
-                    var footer = makeRow('suggest-row suggest-footer', true);
-                    footer.td.textContent = 'Show all ' + state.total + ' matches';
-                    var footerIdx = state.results.length;
-                    if (state.activeIdx === footerIdx) footer.tr.classList.add('is-active');
-                    footer.tr.addEventListener('mousedown', function (e) {
-                        e.preventDefault();
-                        pickFooter();
-                    });
-                    tbody.appendChild(footer.tr);
-                }
-            }
-            dropdown.appendChild(table);
-            dropdown.classList.add('is-open');
-        }
-
-        function pick(idx) {
-            var r = state.results[idx];
-            if (!r) return;
-            close();
-            if (opts.onPick) opts.onPick(r);
-        }
-
-        function pickFooter() {
-            close();
-            if (opts.onShowAll) {
-                opts.onShowAll(state.query);
-            } else if (inputEl.form) {
-                inputEl.form.submit();
-            } else {
-                window.location.href = '/?q=' + encodeURIComponent(state.query);
-            }
+        function isOpen() {
+            return dropdown.classList.contains('is-open');
         }
 
         function open() {
-            state.open = true;
-            render();
+            if (dropdown.firstElementChild) dropdown.classList.add('is-open');
         }
 
         function close() {
-            state.open = false;
-            state.activeIdx = -1;
-            render();
+            dropdown.classList.remove('is-open');
+            setActive(-1);
         }
 
-        function fetchResults(query) {
-            var seq = ++state.reqSeq;
-            fetch('/_search?q=' + encodeURIComponent(query), {
-                credentials: 'same-origin',
-                headers: { 'Accept': 'application/json' },
-            }).then(function (r) {
-                if (!r.ok) throw new Error('HTTP ' + r.status);
-                return r.json();
-            }).then(function (resp) {
-                if (seq !== state.reqSeq) return; // stale
-                state.results = resp.results || [];
-                state.total = resp.total || 0;
-                state.query = resp.query || query;
-                state.activeIdx = -1;
-                open();
-            }).catch(function () {
-                if (seq !== state.reqSeq) return;
-                state.results = [];
-                state.total = 0;
-                close();
-            });
-        }
-
-        function onInput() {
-            var q = inputEl.value.trim();
-            state.query = q;
-            if (state.debounceTimer) clearTimeout(state.debounceTimer);
-            if (q.length < MIN_QUERY_LEN) {
-                state.reqSeq++; // invalidate any in-flight response
-                state.results = [];
-                state.total = 0;
-                close();
-                return;
+        function setActive(idx) {
+            var rs = rows();
+            if (rs[activeIdx]) rs[activeIdx].classList.remove('is-active');
+            activeIdx = idx;
+            if (rs[idx]) {
+                rs[idx].classList.add('is-active');
+                try { rs[idx].scrollIntoView({ block: 'nearest' }); } catch (e) {}
             }
-            state.debounceTimer = setTimeout(function () {
-                fetchResults(q);
-            }, DEBOUNCE_MS);
         }
 
         function moveActive(delta) {
-            var n = rowCount();
+            var n = rows().length;
             if (n === 0) return;
-            var next = state.activeIdx + delta;
+            var next = activeIdx + delta;
             if (next < 0) next = n - 1;
             if (next >= n) next = 0;
-            state.activeIdx = next;
-            render();
-            // Keep the active row in view.
-            var active = dropdown.querySelector('tr.is-active');
-            if (active && active.scrollIntoView) {
-                try { active.scrollIntoView({ block: 'nearest' }); } catch (e) {}
+            setActive(next);
+        }
+
+        // pick activates a row: onPick for data rows when given, otherwise
+        // (and always for the footer) the row's link.
+        function pick(row) {
+            close();
+            if (opts.onPick && !row.classList.contains('suggest-footer')) {
+                opts.onPick({ name: row.dataset.name });
+            } else {
+                row.querySelector('a').click();
             }
         }
 
-        function activateCurrent() {
-            if (state.activeIdx < 0) return false;
-            if (isFooterIdx(state.activeIdx)) {
-                pickFooter();
-                return true;
-            }
-            pick(state.activeIdx);
-            return true;
-        }
-
-        inputEl.addEventListener('input', onInput);
-        inputEl.addEventListener('focus', function () {
-            if (state.blurTimer) {
-                clearTimeout(state.blurTimer);
-                state.blurTimer = null;
-            }
-            if (inputEl.value.trim().length >= MIN_QUERY_LEN
-                    && (state.results.length || state.query)) {
+        dropdown.addEventListener('htmx:afterSwap', function () {
+            activeIdx = -1;
+            if (document.activeElement === inputEl && dropdown.firstElementChild) {
                 open();
+            } else {
+                close();
             }
         });
-        inputEl.addEventListener('blur', function () {
-            // Delay so click/mousedown on a row still resolves.
-            state.blurTimer = setTimeout(close, 150);
+
+        // mousedown keeps focus in the input so blur doesn't close the
+        // dropdown before the click lands.
+        dropdown.addEventListener('mousedown', function (e) { e.preventDefault(); });
+        dropdown.addEventListener('click', function (e) {
+            var row = e.target.closest('.suggest-row');
+            if (!row) return;
+            if (opts.onPick && !row.classList.contains('suggest-footer')) {
+                e.preventDefault();
+                pick(row);
+            } else {
+                close(); // the link navigates
+            }
         });
+
+        inputEl.addEventListener('focus', open);
+        inputEl.addEventListener('blur', close);
         inputEl.addEventListener('keydown', function (e) {
+            if (!isOpen()) return;
             if (e.key === 'ArrowDown') {
-                if (!state.open) return;
                 e.preventDefault();
                 moveActive(1);
             } else if (e.key === 'ArrowUp') {
-                if (!state.open) return;
                 e.preventDefault();
                 moveActive(-1);
             } else if (e.key === 'Escape') {
-                if (!state.open) return;
                 e.preventDefault();
                 close();
             } else if (e.key === 'Enter') {
-                if (state.open && state.activeIdx >= 0) {
+                // Without an active row: native submit (full results page).
+                var row = rows()[activeIdx];
+                if (row) {
                     e.preventDefault();
-                    activateCurrent();
+                    pick(row);
                 }
-                // else: native form submit behaviour (full results page)
             } else if (e.key === 'Tab') {
-                if (!state.open || rowCount() === 0) return;
+                if (rows().length === 0) return;
                 e.preventDefault();
                 moveActive(e.shiftKey ? -1 : 1);
             }
         });
 
-        // Click outside the host closes the dropdown.
-        document.addEventListener('mousedown', function (e) {
-            if (!state.open) return;
-            if (host.contains(e.target)) return;
-            close();
-        });
-
         return {
             close: close,
             destroy: function () {
@@ -310,14 +144,7 @@
 
     window.attachSuggestions = attachSuggestions;
 
-    // Auto-bind to the header search input. Header search submits the form
-    // for the "show all" action; we route to a navigate-on-pick handler.
     document.addEventListener('DOMContentLoaded', function () {
-        var input = document.querySelector('header .search-input');
-        if (!input) return;
-        attachSuggestions(input, {
-            showFooter: true,
-            onPick: function (r) { window.location.href = r.url; },
-        });
+        attachSuggestions(document.querySelector('header .search-input'), { showFooter: true });
     });
 })();

assets/search/actions.js

@@ -52,19 +52,19 @@ function createSearchPage(name) {
     });
 }
 
+// The "create page" link on results pages; delegated, since boosted
+// navigation swaps the results in without a new DOMContentLoaded.
+document.addEventListener('click', function (e) {
+    var createLink = e.target.closest && e.target.closest('[data-create-page]');
+    if (!createLink) return;
+    e.preventDefault();
+    createSearchPage(createLink.getAttribute('data-create-page'));
+});
+
+// Focus the search input on results pages so Tab steps directly into the
+// first match — the input sits immediately before the results in DOM order,
+// so the natural tab sequence is input → first result → next, …
 document.addEventListener('DOMContentLoaded', function () {
-
-    var createLink = document.querySelector('[data-create-page]');
-    if (createLink) {
-        createLink.addEventListener('click', function (e) {
-            e.preventDefault();
-            createSearchPage(createLink.getAttribute('data-create-page'));
-        });
-    }
-
-    // Focus the search input on results pages so Tab steps directly into the
-    // first match — the input sits immediately before the results in DOM
-    // order, so the natural tab sequence is input → first result → next, …
     var input = document.querySelector('.search-input');
     if (input && input.value) {
         input.focus();
@@ -72,3 +72,12 @@ document.addEventListener('DOMContentLoaded', function () {
         try { input.setSelectionRange(end, end); } catch (e) {}
     }
 });
+
+// The header (and its search box) survives boosted navigation: show the
+// current page's query, as a full load would.
+document.addEventListener('page:swapped', function () {
+    var input = document.querySelector('.search-input');
+    if (input && document.activeElement !== input) {
+        input.value = new URLSearchParams(location.search).get('q') || '';
+    }
+});

assets/search/main.html

@@ -1,5 +1,3 @@
-{{define "headScripts"}}<script src="{{asset "search/actions.js"}}"></script>{{end}}
-
 {{define "searchQuery"}}{{.Query}}{{end}}
 
 {{define "content"}}

assets/search/suggest.html

@@ -0,0 +1,8 @@
+{{/* Search typeahead dropdown (/_search, htmx requests). Rows are links, so a
+pick in the header is plain navigation; the editor's link dialog intercepts
+the click and reads data-name. Empty output closes the dropdown. */}}
+{{define "suggest"}}{{if .Show}}<table class="data-table"><tbody>
+{{range .Results}}<tr class="suggest-row" data-name="{{.Name}}"><td><a class="suggest-link" href="{{.URL}}" tabindex="-1"><span class="suggest-name">{{.Highlighted}}</span><span class="suggest-path">/{{.Path}}</span></a></td></tr>
+{{else}}<tr class="is-empty"><td>No matches</td></tr>
+{{end}}{{if .AllURL}}<tr class="suggest-row suggest-footer"><td><a class="suggest-link" href="{{.AllURL}}" tabindex="-1">Show all {{.Total}} matches</a></td></tr>
+{{end}}</tbody></table>{{end}}{{end}}

assets/style.css

@@ -241,6 +241,20 @@ footer {
 .danger { color: var(--danger); }
 .danger:hover { color: var(--danger-hover); }
 .btn.is-active { color: var(--primary-hover); }
+/* Segmented choice: radios styled as .btn toggles. The label is the button;
+   the input stays in the accessibility tree and keyboard order. */
+.segmented input {
+    position: absolute;
+    opacity: 0;
+    width: 1px;
+    height: 1px;
+    margin: 0;
+}
+.segmented .btn { position: relative; }
+.segmented .btn:has(input:checked) { color: var(--primary-hover); }
+.segmented .btn:has(input:focus-visible) { outline: 1px solid var(--secondary); }
+fieldset { border: 0; margin: 0; padding: 0; min-width: 0; }
+legend { padding: 0; margin-bottom: var(--space-1); } /* not a flex item: .gap-* skips it */
 
 /* === Form controls ===
    .input baseline is shared by search-input, modal inputs, and the editor
@@ -411,6 +425,8 @@ main > h2 {
 .dropdown-menu.scrollable { max-height: 23rem; overflow-y: auto; }
 
 .actions-special > .btn {text-align: left;}
+/* Wrapper for the out-of-band swapped page actions; lays out as if absent. */
+.page-actions { display: contents; }
 /* Header actions carry an icon and a label: the mobile dropdown shows the
    label, the inline desktop bar (see responsive block) the icon. */
 .btn-icon { display: none; }
@@ -433,11 +449,13 @@ main > h2 {
 }
 .suggest-dropdown.is-open { display: block; }
 .suggest-row { cursor: pointer; }
-.suggest-row > td { padding: 0.4rem 0.6rem; }
+.suggest-row > td { padding: 0; }
+/* The link fills the row, so every part of it is the click target. */
+.suggest-link { display: block; padding: 0.4rem 0.6rem; color: inherit; text-decoration: none; }
 .suggest-name, .suggest-path { display: block; }
 .suggest-name { color: var(--text); }
 .suggest-path { color: var(--text-muted); font-size: 0.8rem; margin-top: 0.1rem; }
-.suggest-footer > td { color: var(--link); font-size: var(--font-sm); }
+.suggest-footer .suggest-link { color: var(--link); font-size: var(--font-sm); }
 
 /* === Editor toolbar ===
    Single non-wrapping row that scrolls horizontally (swipe on mobile) rather
@@ -733,17 +751,33 @@ aside.sidebar:empty { display: none; }
     padding: 0.25rem var(--space-1);
     cursor: pointer;
 }
-.tree-row:hover, .tree-row.is-selected { background: var(--bg-panel-hover); }
-.tree-row.is-selected {
-    border-left: 3px solid var(--primary);
-    padding-left: calc(var(--space-2) - 3px);
-}
+.tree-row:hover { background: var(--bg-panel-hover); }
 .tree-row.is-active > .tree-name { color: var(--secondary); }
 .tree-row.is-disabled { color: var(--text-muted); cursor: default; }
 .tree-row.is-disabled:hover { background: none; }
 .tree-chevron { text-align: center; flex-shrink: 0; }
 .tree-chevron { width: 1.25rem; color: var(--secondary); }
 .tree-chevron.is-leaf { visibility: hidden; }
+/* Expandable folders are <details>; the chevron follows its open state. */
+.tree-node > summary { list-style: none; }
+.tree-node > summary::-webkit-details-marker { display: none; }
+.tree-node > summary > .tree-chevron::before { content: "\25b8"; }
+.tree-node[open] > summary > .tree-chevron::before { content: "\25be"; }
+/* Picker rows select through a visually hidden radio in the name label. */
+.tree-name input[type="radio"] {
+    position: absolute;
+    opacity: 0;
+    width: 1px;
+    height: 1px;
+    margin: 0;
+}
+.tree-row:has(input:checked) {
+    background: var(--bg-panel-hover);
+    border-left: 3px solid var(--primary);
+    padding-left: calc(var(--space-2) - 3px);
+}
+.tree-row:has(input:focus-visible) { outline: 1px solid var(--secondary); }
+label.tree-name { flex: 1; cursor: pointer; position: relative; }
 .tree-name { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 .tree-children {
     margin-left: var(--space-2);

assets/tree-picker.js

@@ -1,43 +1,29 @@
+// openTreePicker shows a modal to pick a wiki path. The tree is server-rendered
+// (?tree&pick=…, see tree.go and tree.html): each selectable row carries a
+// radio named "pick", folders expand natively and lazy-load via htmx. This
+// file only hosts the tree in a modal and reports the checked row.
+//
+// opts: title, confirmLabel, mode ('folder' | 'file' | 'any'), initialPath
+// (expanded on open), preselect (checked on open), hideFiles, allowRoot
+// (default true: offer "/" in folder modes), onSelect(path, kind).
 (function () {
-    function joinPath(parent, name) {
-        if (parent === '/' || parent === '') return '/' + name;
-        return parent.replace(/\/+$/, '') + '/' + name;
-    }
-
-    function encodePath(p) {
-        if (p === '/' || p === '') return '/';
-        return '/' + p.replace(/^\/+/, '').split('/').map(encodeURIComponent).join('/') + '/';
-    }
-
-    function fetchFolder(path) {
-        return fetch(encodePath(path) + '?tree=1', { credentials: 'same-origin' })
-            .then(function (r) {
-                if (!r.ok) throw new Error('HTTP ' + r.status);
-                return r.json();
-            });
-    }
-
     function openTreePicker(opts) {
         opts = opts || {};
         var mode = opts.mode || 'folder';
-        var initialPath = opts.initialPath || '/';
-        var allowRoot = opts.allowRoot !== false;
-        var hideFiles = !!opts.hideFiles;
-        var preselect = opts.preselect || null;
 
         var container = document.createElement('div');
-
         var treeEl = document.createElement('div');
         treeEl.className = 'tree-picker panel';
-
+        treeEl.textContent = '…';
         var selectedPathEl = document.createElement('div');
         selectedPathEl.className = 'tree-selected-path muted';
-        selectedPathEl.textContent = '\u00a0';
-
+        selectedPathEl.textContent = ' ';
         container.appendChild(treeEl);
         container.appendChild(selectedPathEl);
 
-        var selected = null; // { path, kind, rowEl }
+        function checked() {
+            return treeEl.querySelector('input[name="pick"]:checked');
+        }
 
         var handle = openModal({
             title: opts.title || 'Pick',
@@ -46,236 +32,34 @@
                 label: opts.confirmLabel || 'SELECT',
                 initiallyDisabled: true,
                 onConfirm: function () {
-                    if (!selected) return;
+                    var pick = checked();
+                    if (!pick) return;
                     handle.close();
-                    if (opts.onSelect) opts.onSelect(selected.path, selected.kind);
+                    if (opts.onSelect) opts.onSelect(pick.value, pick.dataset.kind);
                 }
             }
         });
 
-        function setSelected(path, kind, rowEl) {
-            if (selected && selected.rowEl) selected.rowEl.classList.remove('is-selected');
-            selected = { path: path, kind: kind, rowEl: rowEl };
-            rowEl.classList.add('is-selected');
-            selectedPathEl.textContent = path;
-            handle.setConfirmDisabled(false);
+        function sync() {
+            var pick = checked();
+            selectedPathEl.textContent = pick ? pick.value : ' ';
+            handle.setConfirmDisabled(!pick);
         }
+        treeEl.addEventListener('change', sync);
 
-        function isSelectable(kind) {
-            if (mode === 'any') return true;
-            if (mode === 'folder') return kind === 'folder';
-            if (mode === 'file') return kind === 'file';
-            return false;
-        }
-
-        // buildRow returns { rowEl, expand(): Promise }. `expand` is a no-op
-        // for files and idempotent for folders (resolves with the already-
-        // loaded children on repeat calls).
-        function buildRow(parentPath, name, kind) {
-            var row = document.createElement('div');
-            row.className = 'tree-row';
-            if (!isSelectable(kind)) row.classList.add('is-disabled');
-
-            var chevron = document.createElement('span');
-            chevron.className = 'tree-chevron';
-            if (kind === 'folder') {
-                chevron.textContent = '\u25b8'; // ▸
-            } else {
-                chevron.classList.add('is-leaf');
+        var url = '/?tree&pick=' + mode +
+            (opts.hideFiles ? '' : '&files=1') +
+            (opts.allowRoot !== false ? '&root=1' : '') +
+            '&expandTo=' + encodeURIComponent(opts.initialPath || '/') +
+            (opts.preselect ? '&select=' + encodeURIComponent(opts.preselect) : '');
+        htmx.ajax('GET', url, { target: treeEl, swap: 'innerHTML' }).then(function () {
+            sync();
+            var pick = checked();
+            if (pick) {
+                try { pick.closest('.tree-row').scrollIntoView({ block: 'nearest' }); } catch (e) {}
             }
-            row.appendChild(chevron);
-
-            var label = document.createElement('span');
-            label.className = 'tree-name';
-            label.textContent = name;
-            row.appendChild(label);
-
-            var fullPath = joinPath(parentPath, name);
-            var childrenEl = null;
-            var loadPromise = null;
-            var isOpen = false;
-
-            function expand() {
-                if (kind !== 'folder') return Promise.resolve(null);
-                if (isOpen) return loadPromise || Promise.resolve(childrenEl);
-                if (!childrenEl) {
-                    childrenEl = document.createElement('div');
-                    childrenEl.className = 'tree-children';
-                }
-                row.parentNode.insertBefore(childrenEl, row.nextSibling);
-                chevron.textContent = '\u25be'; // ▾
-                isOpen = true;
-                if (!loadPromise) {
-                    loadPromise = loadInto(fullPath, childrenEl);
-                }
-                return loadPromise;
-            }
-
-            function collapse() {
-                if (kind !== 'folder' || !isOpen) return;
-                if (childrenEl && childrenEl.parentNode) {
-                    childrenEl.parentNode.removeChild(childrenEl);
-                }
-                chevron.textContent = '\u25b8';
-                isOpen = false;
-            }
-
-            chevron.addEventListener('click', function (e) {
-                e.stopPropagation();
-                if (isOpen) collapse(); else expand();
-            });
-
-            row.addEventListener('click', function () {
-                if (isSelectable(kind)) {
-                    setSelected(fullPath, kind, row);
-                } else if (kind === 'folder') {
-                    if (isOpen) collapse(); else expand();
-                }
-            });
-
-            if (kind === 'folder') {
-                row.addEventListener('dblclick', function (e) {
-                    e.preventDefault();
-                    if (isOpen) collapse(); else expand();
-                });
-            }
-
-            return {
-                rowEl: row,
-                name: name,
-                kind: kind,
-                childrenEl: function () { return childrenEl; },
-                expand: expand
-            };
-        }
-
-        // loadInto fetches folderPath and populates `target` with rows. Returns
-        // an array of the row objects on success, or [] on failure.
-        function loadInto(folderPath, target) {
-            target.textContent = '';
-            var loading = document.createElement('div');
-            loading.className = 'tree-row is-disabled';
-            loading.textContent = '\u2026';
-            target.appendChild(loading);
-
-            return fetchFolder(folderPath).then(function (resp) {
-                target.textContent = '';
-                var rows = [];
-                (resp.entries || []).forEach(function (e) {
-                    if (hideFiles && e.kind !== 'folder') return;
-                    var r = buildRow(resp.path, e.name, e.kind);
-                    target.appendChild(r.rowEl);
-                    rows.push(r);
-                });
-                if (rows.length === 0) {
-                    var empty = document.createElement('div');
-                    empty.className = 'tree-row is-disabled';
-                    empty.textContent = '(empty)';
-                    target.appendChild(empty);
-                }
-                return rows;
-            }).catch(function () {
-                target.textContent = '';
-                var err = document.createElement('div');
-                err.className = 'tree-row';
-                err.textContent = '(failed — tap to retry)';
-                err.addEventListener('click', function () {
-                    loadInto(folderPath, target);
-                });
-                target.appendChild(err);
-                return [];
-            });
-        }
-
-        // Root selection row — visible when allowRoot and mode accepts folders.
-        if (allowRoot && isSelectable('folder')) {
-            var rootRow = document.createElement('div');
-            rootRow.className = 'tree-row';
-            var rootChev = document.createElement('span');
-            rootChev.className = 'tree-chevron is-leaf';
-            rootRow.appendChild(rootChev);
-            var rootLabel = document.createElement('span');
-            rootLabel.className = 'tree-name';
-            rootLabel.textContent = '/';
-            rootRow.appendChild(rootLabel);
-            rootRow.addEventListener('click', function () {
-                setSelected('/', 'folder', rootRow);
-            });
-            treeEl.appendChild(rootRow);
-        }
-
-        var rootChildren = document.createElement('div');
-        treeEl.appendChild(rootChildren);
-
-        // Expand the ancestor chain of initialPath so the user lands in
-        // context. For root, just load root children.
-        var segs = (initialPath || '/').split('/').filter(Boolean);
-        var preselectSegs = preselect
-            ? preselect.split('/').filter(Boolean)
-            : null;
-
-        loadInto('/', rootChildren).then(function (rows) {
-            return expandChain(rows, segs, '/');
-        }).then(function () {
-            if (preselectSegs === null) return;
-            if (preselectSegs.length === 0) {
-                // Preselect root itself (if allowed).
-                if (allowRoot && isSelectable('folder')) {
-                    var root = treeEl.querySelector('.tree-row');
-                    if (root) setSelected('/', 'folder', root);
-                }
-                return;
-            }
-            selectByPath(preselectSegs);
         });
 
-        // expandChain walks `segments`, looking up each by name in the current
-        // row list, expanding it, and recursing into its children.
-        function expandChain(rows, segments, basePath) {
-            if (segments.length === 0) return Promise.resolve();
-            var seg = segments[0];
-            var match = null;
-            for (var i = 0; i < rows.length; i++) {
-                if (rows[i].kind === 'folder' && rows[i].name === seg) {
-                    match = rows[i];
-                    break;
-                }
-            }
-            if (!match) return Promise.resolve();
-            return match.expand().then(function (childRows) {
-                return expandChain(childRows || [], segments.slice(1), joinPath(basePath, seg));
-            });
-        }
-
-        // selectByPath walks the visible tree rows to locate the row matching
-        // `segments` and marks it selected. Assumes its ancestors are already
-        // expanded (expandChain ran first).
-        function selectByPath(segments) {
-            var container = rootChildren;
-            var path = '/';
-            for (var i = 0; i < segments.length; i++) {
-                var seg = segments[i];
-                var kids = container.children;
-                var found = null;
-                for (var j = 0; j < kids.length; j++) {
-                    var row = kids[j];
-                    if (!row.classList || !row.classList.contains('tree-row')) continue;
-                    var nm = row.querySelector('.tree-name');
-                    if (nm && nm.textContent === seg) { found = row; break; }
-                }
-                if (!found) return;
-                path = joinPath(path, seg);
-                if (i === segments.length - 1) {
-                    if (isSelectable('folder')) setSelected(path, 'folder', found);
-                    try { found.scrollIntoView({ block: 'nearest' }); } catch (e) {}
-                    return;
-                }
-                var next = found.nextSibling;
-                if (!next || !next.classList || !next.classList.contains('tree-children')) return;
-                container = next;
-            }
-        }
-
         return handle;
     }
 

assets/tree-sidebar.js

@@ -1,245 +0,0 @@
-;(function () {
-  // This script owns the .tree-scroll child of the aside, not the aside itself.
-  var container = document.querySelector("aside.tree-sidebar .tree-scroll")
-  if (!container) return
-
-  function joinPath(parent, name) {
-    if (parent === "/" || parent === "") return "/" + name
-    return parent.replace(/\/+$/, "") + "/" + name
-  }
-
-  function encodeSegments(p) {
-    return p.replace(/^\/+/, "").split("/").map(encodeURIComponent).join("/")
-  }
-
-  function folderHref(p) {
-    if (p === "/" || p === "") return "/"
-    return "/" + encodeSegments(p) + "/"
-  }
-
-  function fetchFolder(path, expandTo) {
-    var url = folderHref(path) + "?tree=1&foldersOnly=1"
-    if (expandTo) url += "&expandTo=" + encodeURIComponent(expandTo)
-    return fetch(url, { credentials: "same-origin" }).then(function (r) {
-      if (!r.ok) throw new Error("HTTP " + r.status)
-      return r.json()
-    })
-  }
-
-  // Current page as a canonical, DECODED wiki path ("/" for root, no trailing
-  // slash otherwise). pathname is percent-encoded; the tree's entry names (and
-  // thus fullPath) are decoded, so we must decode here too or paths containing
-  // spaces / non-ASCII never match a row and the chain never expands.
-  var activePath = (function () {
-    var p = window.location.pathname.replace(/\/+$/, "")
-    if (p === "") return "/"
-    try {
-      return decodeURIComponent(p)
-    } catch (e) {
-      return p
-    }
-  })()
-  var activeRow = null
-  var live = false // set once the fetched tree is on screen
-
-  function disabledRow(text) {
-    var row = document.createElement("div")
-    row.className = "tree-row is-disabled"
-    row.textContent = text
-    return row
-  }
-
-  // renderInto fills containerEl with rows for `entries` (children of
-  // parentPath). Folders carrying a `children` array (the pre-expanded
-  // ancestor chain from ?expandTo) are opened immediately and recurse.
-  function renderInto(containerEl, parentPath, entries) {
-    entries.forEach(function (entry) {
-      var built = buildRow(parentPath, entry)
-      containerEl.appendChild(built.row)
-      if (built.preExpand) built.open()
-    })
-  }
-
-  function buildRow(parentPath, entry) {
-    var fullPath = joinPath(parentPath, entry.name)
-    var row = document.createElement("div")
-    row.className = "tree-row"
-
-    var chevron = document.createElement("span")
-    chevron.className = "tree-chevron"
-    chevron.textContent = "▸"
-    row.appendChild(chevron)
-
-    var link = document.createElement("a")
-    link.className = "tree-name tree-folder"
-    link.textContent = entry.name
-    link.href = folderHref(fullPath)
-    row.appendChild(link)
-
-    if (fullPath === activePath) {
-      row.classList.add("is-active")
-      activeRow = row
-    }
-
-    var preChildren = entry.children ? entry.children : null
-    var childrenEl = null
-    var loaded = false
-    var isOpen = false
-    var isLeaf = !entry.hasChildren
-    if (isLeaf) chevron.classList.add("is-leaf")
-
-    function ensureChildrenEl() {
-      if (!childrenEl) {
-        childrenEl = document.createElement("div")
-        childrenEl.className = "tree-children"
-      }
-      return childrenEl
-    }
-
-    function markLeaf() {
-      isLeaf = true
-      isOpen = false
-      chevron.textContent = "▸"
-      chevron.classList.add("is-leaf")
-      if (childrenEl && childrenEl.parentNode) {
-        childrenEl.parentNode.removeChild(childrenEl)
-      }
-    }
-
-    function loadChildren() {
-      var el = ensureChildrenEl()
-      el.textContent = ""
-      el.appendChild(disabledRow("…"))
-      fetchFolder(fullPath)
-        .then(function (resp) {
-          el.textContent = ""
-          loaded = true
-          if (!resp.entries || resp.entries.length === 0) {
-            markLeaf()
-            return
-          }
-          renderInto(el, fullPath, resp.entries)
-        })
-        .catch(function () {
-          el.textContent = ""
-          var err = document.createElement("div")
-          err.className = "tree-row"
-          err.textContent = "(failed — tap to retry)"
-          err.addEventListener("click", function (e) {
-            e.stopPropagation()
-            loadChildren()
-          })
-          el.appendChild(err)
-        })
-    }
-
-    function open() {
-      if (isOpen || isLeaf) return
-      var el = ensureChildrenEl()
-      row.parentNode.insertBefore(el, row.nextSibling)
-      chevron.textContent = "▾" // ▾
-      isOpen = true
-      if (!loaded) {
-        if (preChildren) {
-          renderInto(el, fullPath, preChildren)
-          loaded = true
-        } else {
-          loadChildren()
-        }
-      }
-    }
-
-    function close() {
-      if (!isOpen) return
-      if (childrenEl && childrenEl.parentNode) {
-        childrenEl.parentNode.removeChild(childrenEl)
-      }
-      chevron.textContent = "▸"
-      isOpen = false
-    }
-
-    // Clicking the name link navigates (folder) or opens the file; clicking
-    // anywhere else on the row toggles expansion for folders.
-    row.addEventListener("click", function (e) {
-      if (e.target.closest("a.tree-name")) return
-      if (isOpen) close()
-      else open()
-    })
-
-    return { row: row, open: open, preExpand: !!preChildren }
-  }
-
-  function render() {
-    // If the layout pre-painted a snapshot of the previous page's tree, keep it
-    // on screen and build the live tree off-DOM, swapping it in once ready —
-    // no "…" placeholder, no scroll jump.
-    var listing = document.createElement("div")
-    var hasSnapshot = container.firstChild !== null
-    if (!hasSnapshot) {
-      container.appendChild(listing)
-      listing.appendChild(disabledRow("…"))
-    }
-
-    fetchFolder("/", activePath === "/" ? "" : activePath)
-      .then(function (resp) {
-        listing.textContent = ""
-        renderInto(listing, "/", resp.entries)
-        if (hasSnapshot) {
-          var top = container.scrollTop
-          container.replaceChildren(listing)
-          container.scrollTop = top
-        }
-        live = true
-        if (activeRow) {
-          try {
-            activeRow.scrollIntoView({ block: "nearest" })
-          } catch (e) {}
-        }
-      })
-      .catch(function () {
-        live = false
-        container.replaceChildren(listing)
-        listing.textContent = ""
-        var err = document.createElement("div")
-        err.className = "tree-row"
-        err.textContent = "(failed — tap to retry)"
-        err.addEventListener("click", function () {
-          container.textContent = ""
-          render()
-        })
-        listing.appendChild(err)
-      })
-  }
-
-  // Snapshot the tree (markup + scroll) on the way out so the next page's
-  // layout can paint it immediately. Skipped until the live tree has rendered,
-  // so a placeholder or error row never becomes the snapshot. The active
-  // highlight is left out; the next page marks its own row.
-  window.addEventListener("pagehide", function () {
-    if (!live) return
-    if (activeRow) activeRow.classList.remove("is-active")
-    var html = container.innerHTML
-    if (activeRow) activeRow.classList.add("is-active") // bfcache may restore this page
-    try {
-      sessionStorage.setItem("tree-snapshot", JSON.stringify({ html: html, top: container.scrollTop }))
-    } catch (e) {}
-  })
-
-  function setupMenuItem() {
-    var specials = document.querySelector(".actions-special")
-    if (!specials) return
-
-    var item = document.createElement("button")
-    item.type = "button"
-    item.className = "btn btn-block"
-    item.title = "Folders"
-    item.textContent = "FOLDERS"
-    item.addEventListener("click", function () {
-      if (typeof openOverlay === "function") openOverlay(container)
-    })
-    specials.appendChild(item)
-  }
-
-  render()
-  setupMenuItem()
-})()

assets/tree.html

@@ -0,0 +1,18 @@
+{{/* Folder tree rows (tree.go), shared by the sidebar and the tree picker.
+Expandable folders are native <details>: open/close needs no script, and a
+folder's children load via htmx the first time it opens, unless the server
+pre-expanded them. A label inside <summary> selects its radio without
+toggling the folder; the rest of the row toggles. */}}
+
+{{define "rows"}}{{range .}}{{if .Expandable}}<details class="tree-node"{{if .Children}} open{{end}}>
+<summary class="{{template "row-class" .}}"><span class="tree-chevron" aria-hidden="true"></span>{{template "label" .}}</summary>
+<div class="tree-children"{{if not .Children}} hx-get="{{.ChildrenURL}}" hx-trigger="toggle once from:closest details"{{end}}>{{template "rows" .Children}}</div>
+</details>
+{{else}}<div class="{{template "row-class" .}}"><span class="tree-chevron is-leaf" aria-hidden="true"></span>{{template "label" .}}</div>
+{{end}}{{end}}{{end}}
+
+{{define "row-class"}}tree-row{{if .Active}} is-active{{end}}{{if and (not .Link) (not .Selectable)}} is-disabled{{end}}{{end}}
+
+{{define "label"}}{{if .Link}}<a class="tree-name tree-{{.Kind}}" href="{{.URL}}">{{.Name}}</a>
+{{- else if .Selectable}}<label class="tree-name"><input type="radio" name="pick" value="{{.Path}}" data-kind="{{.Kind}}"{{if .Checked}} checked{{end}} />{{.Name}}</label>
+{{- else}}<span class="tree-name">{{.Name}}</span>{{end}}{{end}}

dialogs.go

@@ -0,0 +1,84 @@
+package main
+
+import (
+	"html/template"
+	"log"
+	"net/http"
+	"path"
+	"strings"
+)
+
+var dialogTmpl = template.Must(template.New("dialogs").ParseFS(assets, "assets/page/dialogs.html"))
+
+// isHX reports whether r was issued by htmx.
+func isHX(r *http.Request) bool {
+	return r.Header.Get("HX-Request") == "true"
+}
+
+// layoutTemplate names the template that renders a layout page for r: the
+// whole document, or for boosted navigation and htmx history restores only
+// the "partial" that hx.js swaps into the open page. The editor is never
+// boosted.
+func layoutTemplate(w http.ResponseWriter, r *http.Request, editMode bool) string {
+	w.Header().Set("Vary", "HX-Boosted, HX-History-Restore-Request")
+	if !editMode && (r.Header.Get("HX-Boosted") == "true" || r.Header.Get("HX-History-Restore-Request") == "true") {
+		return "partial"
+	}
+	return "layout"
+}
+
+// redirectAfter sends the client to target once a mutation succeeded. htmx
+// requests get HX-Redirect (assets/hx.js turns it into a history replace, so
+// Back skips the pre-mutation page); plain form posts get a 303.
+func redirectAfter(w http.ResponseWriter, r *http.Request, target string) {
+	if isHX(r) {
+		w.Header().Set("HX-Redirect", target)
+		w.WriteHeader(http.StatusNoContent)
+		return
+	}
+	http.Redirect(w, r, target, http.StatusSeeOther)
+}
+
+// pageURL returns the escaped, slash-terminated browser URL of the page at
+// the wiki path p ("/" or "/a/b", trailing slash optional).
+func pageURL(p string) string {
+	p = strings.Trim(p, "/")
+	if p == "" {
+		return "/"
+	}
+	return fileURL(p) + "/"
+}
+
+// renderDialog writes the named dialog from dialogs.html.
+func renderDialog(w http.ResponseWriter, name string, data any) {
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	if err := dialogTmpl.ExecuteTemplate(w, name, data); err != nil {
+		log.Printf("dialog template error: %v", err)
+	}
+}
+
+// serveDialog handles GET ?dialog=<name> for the page at urlPath.
+func (h *handler) serveDialog(w http.ResponseWriter, r *http.Request, urlPath, fsPath string) {
+	page := normalizeMovePath(urlPath)
+	name := r.URL.Query().Get("dialog")
+	if page == "/" && (name == "delete" || name == "move") {
+		http.Error(w, "not available for the wiki root", http.StatusBadRequest)
+		return
+	}
+	switch name {
+	case "view":
+		view, sortKey, order := readPageSettings(fsPath).viewSettings()
+		renderDialog(w, "view", struct{ View, Sort, Order string }{view, sortKey, order})
+	case "delete":
+		renderDialog(w, "delete", struct{ Path string }{urlPath})
+	case "move":
+		// parent comes from the folder picker; default to the current one.
+		parent := r.URL.Query().Get("parent")
+		if parent == "" {
+			parent = path.Dir(page)
+		}
+		renderDialog(w, "move", struct{ Parent, Name string }{parent, path.Base(page)})
+	default:
+		http.NotFound(w, r)
+	}
+}

e2e/.gitignore

@@ -0,0 +1,4 @@
+node_modules/
+.tmp/
+test-results/
+playwright-report/

e2e/package-lock.json

@@ -0,0 +1,58 @@
+{
+  "name": "datascape-e2e",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "datascape-e2e",
+      "devDependencies": {
+        "@playwright/test": "^1"
+      }
+    },
+    "node_modules/@playwright/test": {
+      "version": "1.63.0",
+      "resolved": "https://registry.npmjs.org/@playwright/test/-/test-1.63.0.tgz",
+      "integrity": "sha512-oxMK4vllB9RK5NQ2l1pq1IfOf2AvnEuj/vYGDj0H2nMtmtZpKtCwt/l00GEO6xjGfpBNAvjovvYdCm50dRQkpQ==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright": "1.63.0"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    },
+    "node_modules/playwright": {
+      "version": "1.63.0",
+      "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.63.0.tgz",
+      "integrity": "sha512-+7ziBLidS4NaNCdt57SUDT+wYmmd5fmiQejUic/kb+YsYSCPyOOE9sebzMjNmQrsnNpDJqd4WHvV/8lfKfUDUg==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright-core": "1.63.0"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    },
+    "node_modules/playwright-core": {
+      "version": "1.63.0",
+      "resolved": "https://registry.npmjs.org/playwright-core/-/playwright-core-1.63.0.tgz",
+      "integrity": "sha512-rYCsBF/M5HjUch52bbtVONEFjv6Xu8sm8h72dNlR5bzIE1fvC/bxgspzkjSfU+MweEMmPM8KJebG6nnyxo5mCg==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "playwright-core": "cli.js"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    }
+  }
+}

e2e/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "datascape-e2e",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "test": "playwright test"
+  },
+  "devDependencies": {
+    "@playwright/test": "^1"
+  }
+}

e2e/playwright.config.js

@@ -0,0 +1,30 @@
+import { defineConfig, devices } from "@playwright/test";
+
+const port = process.env.E2E_PORT || "8765";
+
+export default defineConfig({
+  testDir: "tests",
+  // Tests share one server and wiki but each works in its own sandbox folder,
+  // so they can run in parallel.
+  workers: 4,
+  fullyParallel: true,
+  reporter: "list",
+  use: {
+    baseURL: `http://127.0.0.1:${port}`,
+    trace: "retain-on-failure",
+    screenshot: "only-on-failure",
+  },
+  projects: [
+    // The system Chrome; no browser download needed.
+    { name: "chrome", use: { channel: "chrome" } },
+    // Playwright's Firefox build: npx playwright install firefox
+    { name: "firefox", use: { ...devices["Desktop Firefox"] } },
+  ],
+  webServer: {
+    command: "node server.mjs",
+    url: `http://127.0.0.1:${port}/`,
+    timeout: 120_000,
+    reuseExistingServer: false,
+    stdout: "pipe",
+  },
+});

e2e/server.mjs

@@ -0,0 +1,27 @@
+// Builds datascape, seeds a throwaway wiki and runs the server in the
+// foreground. Playwright's webServer starts this and kills it after the run.
+import { execFileSync, spawn } from "node:child_process";
+import { mkdirSync, rmSync, writeFileSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const here = dirname(fileURLToPath(import.meta.url));
+const tmp = join(here, ".tmp");
+const wiki = join(tmp, "wiki");
+const bin = join(tmp, process.platform === "win32" ? "datascape.exe" : "datascape");
+const port = process.env.E2E_PORT || "8765";
+
+rmSync(tmp, { recursive: true, force: true });
+mkdirSync(wiki, { recursive: true });
+
+execFileSync("go", ["build", "-o", bin, "."], { cwd: join(here, ".."), stdio: "inherit" });
+
+// Tests create their own pages (see sandbox in tests/pages.spec.js); the seed
+// is only the home page.
+writeFileSync(join(wiki, "index.md"), "# Home\n\nWelcome.\n");
+
+const srv = spawn(bin, ["-dir", wiki, "-cache", join(tmp, "cache"), "-addr", "127.0.0.1:" + port, "-calendars", ""], {
+  stdio: "inherit",
+});
+srv.on("exit", (code) => process.exit(code ?? 0));
+for (const sig of ["SIGINT", "SIGTERM"]) process.on(sig, () => srv.kill());

e2e/tests/boost.spec.js

@@ -0,0 +1,155 @@
+// Boosted navigation: outside the editor, page links swap the next page into
+// the open document instead of loading a new one. A marker on window survives
+// a boosted navigation and disappears with a full page load.
+import { test, expect } from "@playwright/test";
+import { mkdirSync, readFileSync, writeFileSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const wiki = join(dirname(fileURLToPath(import.meta.url)), "..", ".tmp", "wiki");
+
+test.beforeEach(({ page }) => {
+  page.on("pageerror", (err) => {
+    // Chrome aborts the cross-document view transition (style.css) when the
+    // next document can't take part, e.g. a plain-text file, and reports it
+    // as an unhandled rejection that no page script can catch.
+    if (err.message.includes("ViewTransition opt-in disabled")) return;
+    throw err;
+  });
+});
+
+function randomWord(n) {
+  return Array.from({ length: n }, () => String.fromCharCode(97 + Math.floor(Math.random() * 26))).join("");
+}
+
+function sandbox(pages) {
+  const root = "t" + randomWord(7);
+  for (const [rel, body] of Object.entries(pages)) {
+    const dir = join(wiki, root, rel);
+    mkdirSync(dir, { recursive: true });
+    if (body !== null) writeFileSync(join(dir, "index.md"), body);
+  }
+  return root;
+}
+
+const sidebar = (page) => page.locator("aside.tree-sidebar");
+const link = (scope, name) => scope.getByRole("link", { name, exact: true });
+const mark = (page) => page.evaluate(() => (window.__marker = 1));
+const marked = (page) => page.evaluate(() => window.__marker === 1);
+const long = (title) => `# ${title}\n\n` + Array.from({ length: 40 }, (_, i) => `## Part ${i}\n\ntext\n`).join("\n");
+
+test("sidebar navigation swaps the page in without a reload", async ({ page }) => {
+  const root = sandbox({
+    "": "# Parent\n",
+    Child: "# Child\n\n## First\n\none\n\n## Second\n\n- [ ] boosted task\n",
+  });
+  await page.goto(`/${root}/`);
+  await mark(page);
+  await link(sidebar(page), "Child").click();
+  await expect(page).toHaveURL(new RegExp(`/${root}/Child/$`));
+  await expect(page.locator("main h1")).toContainText("Child");
+  await expect(page).toHaveTitle("Child");
+  expect(await marked(page)).toBe(true);
+  await expect(sidebar(page).locator(".tree-row.is-active")).toHaveText("Child");
+  // Page scripts ran for the new content: TOC and section edit links.
+  await expect(page.locator("nav.toc")).toContainText("Second");
+  await expect(page.locator("main h2", { hasText: "First" }).getByRole("link", { name: "[edit]" })).toBeVisible();
+  // htmx attributes in the new content work: the task toggles.
+  await page.locator("main input.task-checkbox").check();
+  await expect.poll(() => readFileSync(join(wiki, root, "Child", "index.md"), "utf8")).toContain("- [x] boosted task");
+});
+
+test("Back and Forward restore pages and scroll without a reload", async ({ page }) => {
+  const root = sandbox({ "": long("Parent"), Child: long("Child") });
+  await page.goto(`/${root}/`);
+  await mark(page);
+  const center = page.locator(".center");
+  await center.evaluate((el) => (el.scrollTop = 600));
+  await link(sidebar(page), "Child").click();
+  await expect(page.locator("main h1")).toContainText("Child");
+  // A new page starts at the top.
+  expect(await center.evaluate((el) => el.scrollTop)).toBe(0);
+  await page.goBack();
+  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
+  await expect(page.locator("main h1")).toContainText("Parent");
+  await expect(page).toHaveTitle("Parent");
+  await expect.poll(() => center.evaluate((el) => el.scrollTop)).toBeGreaterThan(500);
+  await page.goForward();
+  await expect(page.locator("main h1")).toContainText("Child");
+  expect(await marked(page)).toBe(true);
+});
+
+test("Back to the first, fully loaded page works", async ({ page }) => {
+  const root = sandbox({ "": "# Parent\n", Child: "# Child\n" });
+  await page.goto(`/${root}/Child/`);
+  await mark(page);
+  await link(sidebar(page), root).click();
+  await expect(page.locator("main h1")).toContainText("Parent");
+  await page.goBack();
+  await expect(page).toHaveURL(new RegExp(`/${root}/Child/$`));
+  await expect(page.locator("main h1")).toContainText("Child");
+  expect(await marked(page)).toBe(true);
+});
+
+test("files and the editor load as full pages", async ({ page }) => {
+  const root = sandbox({ "": "# Parent\n" });
+  writeFileSync(join(wiki, root, "note.txt"), "plain file");
+  await page.goto(`/${root}/`);
+  await mark(page);
+  await page.locator("main").getByRole("link", { name: "note.txt" }).click();
+  await expect(page).toHaveURL(new RegExp(`/${root}/note.txt$`));
+  await expect(page.locator("body")).toContainText("plain file");
+  expect(await marked(page)).toBe(false);
+
+  await page.goto(`/${root}/`);
+  await mark(page);
+  await page.locator("header").getByTitle("Edit page (E)").click();
+  await expect(page).toHaveURL(/\?edit/);
+  await expect(page.locator(".cm-content")).toBeVisible();
+  expect(await marked(page)).toBe(false);
+});
+
+test("header actions follow the page", async ({ page }) => {
+  const root = sandbox({ "": "# Parent\n" });
+  await page.goto("/");
+  await mark(page);
+  const move = page.locator("header").getByTitle("Move page (M)");
+  await expect(move).toHaveCount(0);
+  await link(sidebar(page), root).click();
+  await expect(page.locator("main h1")).toContainText("Parent");
+  await expect(move).toBeVisible();
+  await page.goBack();
+  await expect(page.locator("main h1")).toContainText("Home");
+  await expect(move).toHaveCount(0);
+  expect(await marked(page)).toBe(true);
+});
+
+test("search results and the search box follow boosted navigation", async ({ page }) => {
+  const root = sandbox({ "": "# Parent\n", Child: "# Child\n" });
+  expect((await page.request.post("/_reindex")).status()).toBe(204);
+  await page.goto(`/${root}/`);
+  await mark(page);
+  const input = page.locator("header .search-input");
+  await input.fill(root);
+  await input.press("Enter");
+  await expect(page).toHaveURL(new RegExp(`/\?q=${root}$`));
+  await expect(page).toHaveTitle(`Search: ${root}`);
+  await expect(page.locator("main .search-card").first()).toBeVisible();
+  await link(sidebar(page), root).click();
+  await expect(page.locator("main h1")).toContainText("Parent");
+  await expect(input).toHaveValue("");
+  expect(await marked(page)).toBe(true);
+});
+
+test("a mutation swaps in its result without a reload", async ({ page }) => {
+  const root = sandbox({ "": "# Parent\n", Gone: "# Gone\n" });
+  await page.goto(`/${root}/Gone/`);
+  await mark(page);
+  await page.locator("header").getByTitle("Delete page").click();
+  await page.locator(".modal").getByRole("button", { name: "DELETE" }).click();
+  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
+  await expect(page.locator("main h1")).toContainText("Parent");
+  await expect(page.locator(".modal")).toHaveCount(0);
+  await expect(link(sidebar(page), "Gone")).toHaveCount(0);
+  expect(await marked(page)).toBe(true);
+});

e2e/tests/pages.spec.js

@@ -0,0 +1,392 @@
+// End-to-end coverage of the page UI. Tests drive the app through visible
+// labels, not implementation details, so they survive changes to the
+// client-side mechanics.
+//
+// Every test builds the pages it needs under its own fresh top-level folder
+// (sandbox), so tests don't depend on each other's leftovers and can run alone
+// or in any order. Names are matched exactly: other tests' folders share the
+// sidebar and the search index.
+import { test, expect } from "@playwright/test";
+import { mkdirSync, readFileSync, writeFileSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const wiki = join(dirname(fileURLToPath(import.meta.url)), "..", ".tmp", "wiki");
+
+// Fail any test that logs a JS error.
+test.beforeEach(({ page }) => {
+  page.on("pageerror", (err) => {
+    throw err;
+  });
+});
+
+// randomWord returns n random lowercase letters.
+function randomWord(n) {
+  return Array.from({ length: n }, () => String.fromCharCode(97 + Math.floor(Math.random() * 26))).join("");
+}
+
+// sandbox creates a fresh top-level folder holding pages, keyed by path
+// relative to it ("" is the folder's own page); a null body makes an empty
+// folder. Returns the folder name.
+function sandbox(pages) {
+  const root = "t" + randomWord(7);
+  for (const [rel, body] of Object.entries(pages)) {
+    const dir = join(wiki, root, rel);
+    mkdirSync(dir, { recursive: true });
+    if (body !== null) writeFileSync(join(dir, "index.md"), body);
+  }
+  return root;
+}
+
+const readPage = (root, rel = "") => readFileSync(join(wiki, root, rel, "index.md"), "utf8");
+const exactly = (name) => new RegExp(`^${name}$`);
+const sidebar = (page) => page.locator("aside.tree-sidebar");
+const modal = (page) => page.locator(".modal");
+const treeRow = (scope, name) => scope.locator(".tree-row", { hasText: exactly(name) });
+const link = (scope, name) => scope.getByRole("link", { name, exact: true });
+
+// Page actions sit in a dropdown on narrow screens and inline (icon-only) on
+// wide ones; address them by title and open the dropdown only when present.
+async function pageAction(page, title) {
+  const toggle = page.getByRole("button", { name: "ACTIONS" });
+  if (await toggle.isVisible()) await toggle.click();
+  await page.locator("header").getByTitle(title).click();
+}
+
+// movePage runs the move flow from the current page: keep the preselected
+// parent, then enter name.
+async function movePage(page, name) {
+  await pageAction(page, "Move page (M)");
+  await modal(page).getByRole("button", { name: "NEXT" }).click();
+  await modal(page).getByPlaceholder("Page name").fill(name);
+  await modal(page).getByRole("button", { name: "MOVE" }).click();
+}
+
+test("renders a page and navigates via the sidebar", async ({ page }) => {
+  const root = sandbox({ "": "# Parent\n", Child: "# Child\n" });
+  await page.goto("/");
+  await expect(page.locator("main h1")).toContainText("Home");
+  await link(sidebar(page), root).click();
+  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
+  await expect(page.locator("main h1")).toContainText("Parent");
+  // The sidebar expands the active folder's children.
+  await expect(link(sidebar(page), "Child")).toBeVisible();
+});
+
+test("task checkbox toggle persists", async ({ page }) => {
+  const root = sandbox({ "": "# Tasks\n\n- [ ] first task\n- [x] second task\n" });
+  await page.goto(`/${root}/`);
+  const box = page.locator("main input.task-checkbox").first();
+  await expect(box).not.toBeChecked();
+  await box.check();
+  await expect(box).toBeEnabled();
+  await expect.poll(() => readPage(root)).toContain("- [x] first task");
+  await page.reload();
+  await expect(page.locator("main input.task-checkbox").first()).toBeChecked();
+});
+
+test("unchecking a task persists", async ({ page }) => {
+  const root = sandbox({ "": "# Tasks\n\n- [ ] first task\n- [x] second task\n" });
+  await page.goto(`/${root}/`);
+  const box = page.locator("main input.task-checkbox").nth(1);
+  await expect(box).toBeChecked();
+  await box.uncheck();
+  await expect(box).toBeEnabled();
+  await expect.poll(() => readPage(root)).toContain("- [ ] second task");
+});
+
+test("a failed task save reverts the checkbox", async ({ page }) => {
+  const root = sandbox({ "": "# Tasks\n\n- [x] done task\n" });
+  page.on("dialog", (d) => d.dismiss());
+  await page.route("**/?toggle=*", (route) => route.fulfill({ status: 500, body: "boom" }));
+  await page.goto(`/${root}/`);
+  const box = page.locator("main input.task-checkbox").first();
+  await box.click();
+  await expect(box).toBeEnabled();
+  await expect(box).toBeChecked();
+  expect(readPage(root)).toContain("- [x] done task");
+});
+
+test("view settings switch the listing to thumbnails", async ({ page }) => {
+  const root = sandbox({ "": "# Listing\n", Child: "# Child\n" });
+  await page.goto(`/${root}/`);
+  await expect(page.locator("main table.data-table")).toBeVisible();
+  await page.getByTitle("View & sorting").click();
+  await modal(page).getByText("Thumbnail").click();
+  await modal(page).getByLabel("Sort by").selectOption("size");
+  await modal(page).getByText("Desc").click();
+  await modal(page).getByRole("button", { name: "SAVE" }).click();
+  await expect(page.locator("main .thumb-grid")).toBeVisible();
+  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
+  // Reopening shows the saved state.
+  await page.getByTitle("View & sorting").click();
+  await expect(modal(page).getByLabel("Thumbnail")).toBeChecked();
+  await expect(modal(page).getByLabel("Sort by")).toHaveValue("size");
+  await expect(modal(page).getByLabel("Desc")).toBeChecked();
+});
+
+test("editor saves a page", async ({ page }) => {
+  const root = sandbox({ "": "# Editable\n" });
+  await page.goto(`/${root}/`);
+  await pageAction(page, "Edit page (E)");
+  await expect(page).toHaveURL(/\?edit/);
+  await page.locator(".cm-content").click();
+  await page.keyboard.press("Control+End");
+  await page.keyboard.type("\nAdded by e2e.\n");
+  await page.getByRole("button", { name: "SAVE" }).click();
+  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
+  await expect(page.locator("main")).toContainText("Added by e2e.");
+  expect(readPage(root)).toContain("Added by e2e.");
+  // Save replaces the editor's history entry: Back leaves the page entirely.
+  await page.goBack();
+  await expect(page).not.toHaveURL(/\?edit/);
+});
+
+test("move renames a page", async ({ page }) => {
+  const root = sandbox({ Beta: "# Beta\n" });
+  await page.goto(`/${root}/Beta/`);
+  await movePage(page, "Gamma");
+  await expect(page).toHaveURL(new RegExp(`/${root}/Gamma/$`));
+  await expect(page.locator("main h1")).toContainText("Beta");
+});
+
+test("move onto an empty folder offers a merge", async ({ page }) => {
+  const root = sandbox({ Alpha: "# Alpha\n", Empty: null });
+  await page.goto(`/${root}/Alpha/`);
+  await movePage(page, "Empty");
+  await expect(modal(page)).toContainText("Merge folders?");
+  await modal(page).getByRole("button", { name: "MERGE" }).click();
+  await expect(page).toHaveURL(new RegExp(`/${root}/Empty/$`));
+  await expect(page.locator("main h1")).toContainText("Alpha");
+});
+
+test("a failed move shows the server's reason and keeps the dialog", async ({ page }) => {
+  const root = sandbox({ Mover: "# Mover\n", Taken: "# Taken\n" });
+  await page.goto(`/${root}/Mover/`);
+  // Dismiss the alert from the handler: an open alert blocks the click.
+  const messages = [];
+  page.on("dialog", (d) => {
+    messages.push(d.message());
+    d.dismiss();
+  });
+  await movePage(page, "Taken");
+  await expect.poll(() => messages).toEqual([expect.stringContaining("destination already exists")]);
+  await expect(modal(page)).toBeVisible();
+  await expect(page).toHaveURL(new RegExp(`/${root}/Mover/$`));
+});
+
+test("delete removes a page and returns to the parent", async ({ page }) => {
+  const root = sandbox({ "": "# Parent\n", Notes: "# Notes\n" });
+  await page.goto(`/${root}/Notes/`);
+  await pageAction(page, "Delete page");
+  await expect(modal(page)).toContainText(`Delete /${root}/Notes/`);
+  await modal(page).getByRole("button", { name: "DELETE" }).click();
+  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
+  await expect(link(sidebar(page), "Notes")).toHaveCount(0);
+});
+
+test("delete replaces the history entry, so Back skips the deleted page", async ({ page }) => {
+  const root = sandbox({ "": "# Parent\n", Gone: "# Gone\n" });
+  await page.goto(`/${root}/`);
+  await page.goto(`/${root}/Gone/`);
+  await pageAction(page, "Delete page");
+  await modal(page).getByRole("button", { name: "DELETE" }).click();
+  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
+  await page.goBack();
+  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
+});
+
+test("a server dialog works from the first moment it is shown", async ({ page }) => {
+  // htmx wires up swapped-in forms only when it settles. Submit in the very
+  // next task after the dialog is inserted: if the form isn't wired yet, the
+  // browser submits it natively (a GET) and the page is not deleted.
+  const root = sandbox({ "": "# Parent\n", Gone: "# Gone\n" });
+  await page.goto(`/${root}/Gone/`);
+  await page.evaluate(() => {
+    document.addEventListener("htmx:afterSwap", (e) => {
+      if (e.detail.target.id !== "modal-host") return;
+      const submit = e.detail.target.querySelector('button[type="submit"]');
+      setTimeout(() => submit.click(), 0);
+    }, { once: true });
+  });
+  await pageAction(page, "Delete page");
+  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
+});
+
+test("server dialogs close with Escape and CANCEL", async ({ page }) => {
+  const root = sandbox({ "": "# Keep me\n" });
+  await page.goto(`/${root}/`);
+  await pageAction(page, "Delete page");
+  await expect(modal(page)).toBeVisible();
+  // CANCEL is focused, so Enter must not delete.
+  await expect(modal(page).getByRole("button", { name: "CANCEL" })).toBeFocused();
+  await page.keyboard.press("Escape");
+  await expect(modal(page)).toHaveCount(0);
+  await pageAction(page, "Delete page");
+  await modal(page).getByRole("button", { name: "CANCEL" }).click();
+  await expect(modal(page)).toHaveCount(0);
+  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
+  expect(readPage(root)).toContain("Keep me");
+});
+
+test("sidebar tree is in the page itself, no fetch on load", async ({ page }) => {
+  const root = sandbox({ "": "# Here\n" });
+  const treeRequests = [];
+  page.on("request", (r) => {
+    if (r.url().includes("?tree")) treeRequests.push(r.url());
+  });
+  const res = await page.request.get(`/${root}/`);
+  expect(await res.text()).toContain(`class="tree-name tree-folder" href="/${root}/"`);
+  await page.goto(`/${root}/`);
+  await expect(sidebar(page).locator(".tree-row.is-active")).toHaveText(root);
+  expect(treeRequests).toEqual([]);
+});
+
+test("sidebar folders expand lazily and collapse", async ({ page }) => {
+  const root = sandbox({ "One/Deep": "# Deep\n", Two: "# Two\n" });
+  await page.goto("/");
+  const chevron = treeRow(sidebar(page), root).locator(".tree-chevron");
+  const glyph = () => chevron.evaluate((el) => getComputedStyle(el, "::before").content);
+  await expect(link(sidebar(page), "One")).toHaveCount(0);
+  expect(await glyph()).toBe('"▸"');
+  await chevron.click();
+  await expect(link(sidebar(page), "One")).toBeVisible();
+  expect(await glyph()).toBe('"▾"');
+  // One has a subfolder, Two has none: only One gets a chevron.
+  await expect(sidebar(page).locator("summary.tree-row", { hasText: exactly("One") })).toHaveCount(1);
+  await expect(treeRow(sidebar(page), "Two").locator(".tree-chevron")).toHaveClass(/is-leaf/);
+  await chevron.click();
+  await expect(link(sidebar(page), "One")).toBeHidden();
+});
+
+test("tree picker selects inside a lazily expanded folder", async ({ page }) => {
+  const root = sandbox({ Mover: "# Mover\n", "Tree/One/Deep": "# Deep\n" });
+  await page.goto(`/${root}/Mover/`);
+  await pageAction(page, "Move page (M)");
+  // The picker opens with the current parent expanded; Tree is still closed.
+  const picker = modal(page).locator(".tree-picker");
+  await treeRow(picker, "Tree").locator(".tree-chevron").click();
+  await treeRow(picker, "One").locator(".tree-chevron").click();
+  await picker.getByText("Deep", { exact: true }).click();
+  await expect(modal(page).locator(".tree-selected-path")).toHaveText(`/${root}/Tree/One/Deep`);
+  await modal(page).getByRole("button", { name: "NEXT" }).click();
+  await modal(page).getByRole("button", { name: "MOVE" }).click();
+  await expect(page).toHaveURL(new RegExp(`/${root}/Tree/One/Deep/Mover/$`));
+});
+
+test("tree picker can pick the root", async ({ page }) => {
+  const root = sandbox({ Two: "# Two\n" });
+  await page.goto(`/${root}/Two/`);
+  await pageAction(page, "Move page (M)");
+  // The current parent is preselected and its chain expanded.
+  await expect(modal(page).locator(".tree-selected-path")).toHaveText(`/${root}`);
+  await modal(page).locator(".tree-picker").getByText("/", { exact: true }).click();
+  await modal(page).getByRole("button", { name: "NEXT" }).click();
+  await modal(page).getByPlaceholder("Page name").fill(`${root}-top`);
+  await modal(page).getByRole("button", { name: "MOVE" }).click();
+  await expect(page).toHaveURL(new RegExp(`127\\.0\\.0\\.1:\\d+/${root}-top/$`));
+});
+
+test("editor embed picker selects a file", async ({ page }) => {
+  const root = sandbox({ "": "# Embeds\n" });
+  writeFileSync(join(wiki, root, "photo.jpg"), "x");
+  await page.goto(`/${root}/?edit`);
+  await page.locator(".cm-content").click();
+  await page.keyboard.press("Alt+Shift+G");
+  const picker = modal(page).locator(".tree-picker");
+  // Folder rows aren't selectable in file mode; the file is.
+  await picker.getByText("photo.jpg").click();
+  await expect(modal(page).locator(".tree-selected-path")).toHaveText(`/${root}/photo.jpg`);
+  await modal(page).getByRole("button", { name: "NEXT" }).click();
+  await modal(page).getByRole("button", { name: "INSERT" }).click();
+  await expect(page.locator(".cm-content")).toContainText("photo.jpg");
+});
+
+test("mobile: FOLDERS opens the tree in an overlay", async ({ page }) => {
+  const root = sandbox({ "": "# Mobile\n" });
+  await page.setViewportSize({ width: 400, height: 800 });
+  await page.goto(`/${root}/`);
+  await expect(sidebar(page)).toBeHidden();
+  await page.getByRole("button", { name: "ACTIONS" }).click();
+  await page.getByTitle("Folders").click();
+  const overlay = page.locator(".overlay");
+  await expect(link(overlay, root)).toBeVisible();
+  await link(overlay, root).click();
+  await expect(overlay).toHaveCount(0);
+});
+
+// seedSearch creates pages whose names share a random word (so no other
+// test's pages match it) and reindexes. Returns the sandbox, the word and its
+// capitalized form used in the names.
+async function seedSearch(page) {
+  const word = randomWord(8);
+  const Word = word[0].toUpperCase() + word.slice(1);
+  const pages = { "": "# Search\n" };
+  for (const n of ["Zebra Crossing", "Zebra Finch", "1", "2", "3", "4", "5", "6"]) {
+    pages[`${Word} ${n}`] = `# ${Word} ${n}\n`;
+  }
+  const root = sandbox(pages);
+  expect((await page.request.post("/_reindex")).status()).toBe(204);
+  return { root, word, Word };
+}
+const suggest = (page) => page.locator("header .suggest-dropdown");
+
+test("header typeahead: highlight, keyboard pick", async ({ page }) => {
+  const { root, word, Word } = await seedSearch(page);
+  await page.goto("/");
+  const input = page.locator("header .search-input");
+  await input.fill(`${word} finch`);
+  const first = suggest(page).locator(".suggest-row").first();
+  await expect(first.locator(".suggest-name")).toHaveText(`${Word} Zebra Finch`);
+  await expect(first.locator("strong")).toHaveText([Word, "Finch"]);
+  await input.press("ArrowDown");
+  await expect(suggest(page).locator(".suggest-row.is-active")).toContainText(`${Word} Zebra Finch`);
+  await input.press("Enter");
+  await expect(page).toHaveURL(new RegExp(`/${root}/${Word}%20Zebra%20Finch/$`));
+});
+
+test("header typeahead: click, footer, escape, short query", async ({ page }) => {
+  const { root, word, Word } = await seedSearch(page);
+  await page.goto("/");
+  const input = page.locator("header .search-input");
+  await input.fill(word[0]);
+  await page.waitForTimeout(300);
+  await expect(suggest(page)).toBeHidden();
+  await input.fill(word);
+  const { total } = await (await page.request.get(`/_search?q=${word}`)).json();
+  expect(total).toBeGreaterThan(5);
+  await expect(suggest(page).locator(".suggest-footer")).toHaveText(`Show all ${total} matches`);
+  await expect(suggest(page).locator(".suggest-row:not(.suggest-footer)")).toHaveCount(5);
+  await input.press("Escape");
+  await expect(suggest(page)).toBeHidden();
+  await input.fill(`${word} crossing`);
+  await suggest(page).locator(".suggest-name", { hasText: `${Word} Zebra Crossing` }).click();
+  await expect(page).toHaveURL(new RegExp(`/${root}/${Word}%20Zebra%20Crossing/$`));
+  await page.goto("/");
+  await page.locator("header .search-input").fill(word);
+  await suggest(page).locator(".suggest-footer").click();
+  await expect(page).toHaveURL(new RegExp(`/\\?q=${word}$`));
+});
+
+test("editor link dialog fills the query from a suggestion", async ({ page }) => {
+  const { root, word, Word } = await seedSearch(page);
+  await page.goto(`/${root}/?edit`);
+  await page.locator(".cm-content").click();
+  await page.keyboard.press("Alt+Shift+P");
+  const query = modal(page).getByPlaceholder("Search query");
+  await query.fill(`${word} crossing`);
+  await modal(page).locator(".suggest-row", { hasText: `${Word} Zebra Crossing` }).click();
+  await expect(query).toHaveValue(`${Word} Zebra Crossing`);
+  await expect(modal(page).getByPlaceholder("Display text (optional)")).toBeFocused();
+  await modal(page).getByRole("button", { name: "INSERT" }).click();
+  await expect(page.locator(".cm-content")).toContainText(`[[${Word} Zebra Crossing]]`);
+});
+
+test("editor [[ autocomplete lists matching pages", async ({ page }) => {
+  const { root, word, Word } = await seedSearch(page);
+  await page.goto(`/${root}/?edit`);
+  await page.locator(".cm-content").click();
+  await page.keyboard.press("Control+End");
+  await page.keyboard.type(`\n[[${word} finc`);
+  await expect(page.locator(".cm-tooltip-autocomplete")).toContainText(`${Word} Zebra Finch`);
+});

main.go

@@ -301,6 +301,10 @@ func (h *handler) serveDir(w http.ResponseWriter, r *http.Request, urlPath, fsPa
 		h.handlePost(w, r, urlPath, fsPath)
 		return
 	}
+	if r.URL.Query().Has("dialog") {
+		h.serveDialog(w, r, urlPath, fsPath)
+		return
+	}
 
 	for _, ph := range pageTypeHandlers {
 		if target, ok := ph.redirect(h.root, fsPath, urlPath, r); ok {
@@ -402,12 +406,13 @@ func (h *handler) serveDir(w http.ResponseWriter, r *http.Request, urlPath, fsPa
 		Content:        rendered,
 		Entries:        entries,
 		View:           view,
-		Sort:           sortKey,
-		Order:          order,
 		SpecialContent: specialContent,
 		SidebarWidget:  sidebarWidget,
 		SuppressTOC:    suppressTOC,
 	}
+	if !editMode {
+		data.Tree = sidebarTree(h.root, urlPath)
+	}
 
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	t := pageTmpl
@@ -415,7 +420,7 @@ func (h *handler) serveDir(w http.ResponseWriter, r *http.Request, urlPath, fsPa
 		t = editTmpl
 	}
 	data.renderTimer = renderTimer{requestStart(r)}
-	if err := t.ExecuteTemplate(w, "layout", data); err != nil {
+	if err := t.ExecuteTemplate(w, layoutTemplate(w, r, editMode), data); err != nil {
 		log.Printf("template error: %v", err)
 	}
 }
@@ -427,7 +432,18 @@ func (h *handler) handlePost(w http.ResponseWriter, r *http.Request, urlPath, fs
 		return
 	}
 	if _, ok := query["move"]; ok {
-		h.handleMove(w, r, urlPath, fsPath, query.Get("move"), query.Has("merge"))
+		// The destination comes either whole (?move=/dst, or the merge
+		// dialog's move field) or as the move dialog's parent + name.
+		// Body fields take precedence over the bare ?move query key.
+		if err := r.ParseForm(); err != nil {
+			http.Error(w, "bad request", http.StatusBadRequest)
+			return
+		}
+		dst := r.FormValue("move")
+		if name := strings.TrimSpace(r.FormValue("name")); dst == "" && name != "" {
+			dst = strings.TrimRight(r.FormValue("parent"), "/") + "/" + name
+		}
+		h.handleMove(w, r, urlPath, fsPath, dst, r.FormValue("merge") != "")
 		return
 	}
 	if query.Has("toggle") {

moves.go

@@ -14,8 +14,7 @@ import (
 // The one exception is a merge: when the source carries a page (index.md) and
 // the destination folder has none, the source's contents can fill the empty
 // container without clobbering anything. That merge only proceeds when merge
-// is true; otherwise the client is told a merge is available so it can ask the
-// user to confirm.
+// is true; otherwise the client is asked to confirm it.
 func (h *handler) handleMove(w http.ResponseWriter, r *http.Request, srcURL, srcFsPath, dstURL string, merge bool) {
 	oldPath := normalizeMovePath(srcURL)
 	if oldPath == "/" {
@@ -51,9 +50,12 @@ func (h *handler) handleMove(w http.ResponseWriter, r *http.Request, srcURL, src
 			return
 		}
 		if !merge {
-			// Ask the client to confirm the merge. The header lets it tell
-			// this apart from an ordinary conflict.
-			w.Header().Set("X-Merge-Available", "1")
+			// Ask the user to confirm: htmx clients get the merge dialog as
+			// the next step; others a conflict they can retry with &merge=1.
+			if isHX(r) {
+				renderDialog(w, "merge", struct{ Dest string }{newPath})
+				return
+			}
 			http.Error(w, "destination already exists — merge folders?", http.StatusConflict)
 			return
 		}
@@ -94,7 +96,7 @@ func (h *handler) handleMove(w http.ResponseWriter, r *http.Request, srcURL, src
 		folderIndexRenameSubtree(strings.TrimPrefix(oldPath, "/"), strings.TrimPrefix(newPath, "/"))
 	}
 
-	http.Redirect(w, r, fileURL(strings.TrimPrefix(newPath, "/"))+"/", http.StatusSeeOther)
+	redirectAfter(w, r, pageURL(newPath))
 }
 
 // canMergeMove reports whether moving onto an existing destination should
@@ -169,7 +171,7 @@ func (h *handler) handleDelete(w http.ResponseWriter, r *http.Request, urlPath,
 		return
 	}
 	folderIndexRemoveSubtree(strings.TrimPrefix(normalizeMovePath(urlPath), "/"))
-	http.Redirect(w, r, parentURL(urlPath), http.StatusSeeOther)
+	redirectAfter(w, r, pageURL(parentURL(urlPath)))
 }
 
 // normalizeMovePath returns the absolute path with any trailing slash removed,

pagesettings.go

@@ -23,7 +23,7 @@ func (h *handler) handleSettings(w http.ResponseWriter, r *http.Request, urlPath
 		http.Error(w, "write failed: "+err.Error(), http.StatusInternalServerError)
 		return
 	}
-	http.Redirect(w, r, urlPath, http.StatusSeeOther)
+	redirectAfter(w, r, pageURL(urlPath))
 }
 
 // writePageSettings performs a read-modify-write of <dir>/.page-settings,

render.go

@@ -58,11 +58,10 @@ type pageData struct {
 	Content        template.HTML
 	Entries        []entry
 	View           string // listing view style: "list" or "thumbnail"
-	Sort           string // listing sort key: "name" / "modified" / "size"
-	Order          string // listing sort order: "asc" / "desc"
 	SpecialContent template.HTML
 	SidebarWidget  template.HTML
 	SuppressTOC    bool
+	Tree           template.HTML // sidebar folder tree; empty in edit mode
 	renderTimer
 }
 

search.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"html/template"
 	"io/fs"
 	"log"
 	"net/http"
@@ -47,6 +48,7 @@ type searchPageData struct {
 	PageTotal    int
 	FileTotal    int
 	IndexBuiltAt time.Time
+	Tree         template.HTML // sidebar folder tree
 	renderTimer
 }
 
@@ -131,10 +133,11 @@ func (h *handler) handleSearch(w http.ResponseWriter, r *http.Request) {
 		PageTotal:    len(pages),
 		FileTotal:    len(files),
 		IndexBuiltAt: builtAt,
+		Tree:         sidebarTree(h.root, "/"),
 	}
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	data.renderTimer = renderTimer{requestStart(r)}
-	if err := searchTmpl.ExecuteTemplate(w, "layout", data); err != nil {
+	if err := searchTmpl.ExecuteTemplate(w, layoutTemplate(w, r, false), data); err != nil {
 		log.Printf("search template error: %v", err)
 	}
 }
@@ -290,20 +293,23 @@ func scoreName(nameLower string, nameTokens []string, qLower string, qTokens []s
 	return score
 }
 
-// handleSearchSuggest serves the JSON typeahead for the header dropdown and
-// the editor's link picker. Caps results at 5; reports total so the UI can
-// surface a "show all" footer when more matches exist. Empty/whitespace query
-// is a no-op (200 with empty results), not a 400 — every keystroke fires this.
+type suggestResult struct {
+	Name string `json:"name"`
+	Path string `json:"path"`
+	URL  string `json:"url"`
+}
+
+// handleSearchSuggest serves the typeahead: rendered rows for the dropdown
+// (header search, editor link dialog; htmx requests) and JSON for the
+// editor's [[ autocomplete. Caps results at 5; reports total so the dropdown
+// can offer a "show all" footer (?footer) when more matches exist. An
+// empty/whitespace query is a no-op (200, no results), not a 400 — every
+// keystroke fires this.
 func (h *handler) handleSearchSuggest(w http.ResponseWriter, r *http.Request) {
 	if !h.checkAuth(w, r) {
 		return
 	}
 	query := strings.TrimSpace(r.URL.Query().Get("q"))
-	type suggestResult struct {
-		Name string `json:"name"`
-		Path string `json:"path"`
-		URL  string `json:"url"`
-	}
 	type suggestResp struct {
 		Query   string          `json:"query"`
 		Results []suggestResult `json:"results"`
@@ -325,12 +331,92 @@ func (h *handler) handleSearchSuggest(w http.ResponseWriter, r *http.Request) {
 			})
 		}
 	}
+	// htmx (the typeahead dropdown) gets rendered rows; other callers (the
+	// editor's [[ autocomplete) keep the JSON.
+	w.Header().Set("Vary", "HX-Request")
+	if isHX(r) {
+		renderSuggest(w, resp.Query, resp.Results, resp.Total, r.URL.Query().Has("footer"))
+		return
+	}
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	if err := json.NewEncoder(w).Encode(resp); err != nil {
 		log.Printf("search suggest encode error: %v", err)
 	}
 }
 
+var suggestTmpl = template.Must(template.ParseFS(assets, "assets/search/suggest.html"))
+
+// suggestMinLen is the shortest query (in characters) the typeahead answers;
+// shorter ones render nothing, which closes the dropdown.
+const suggestMinLen = 2
+
+type suggestRow struct {
+	Name, Path, URL string
+	Highlighted     template.HTML
+}
+
+// renderSuggest writes the typeahead dropdown for query. footer adds a
+// "Show all" row linking to the full results page when some were cut off.
+func renderSuggest(w http.ResponseWriter, query string, results []suggestResult, total int, footer bool) {
+	data := struct {
+		Show    bool
+		Results []suggestRow
+		Total   int
+		AllURL  string
+	}{Show: utf8.RuneCountInString(query) >= suggestMinLen, Total: total}
+	tokens := suggestTokens(query)
+	for _, res := range results {
+		data.Results = append(data.Results, suggestRow{res.Name, res.Path, res.URL, highlightMatches(res.Name, tokens)})
+	}
+	if footer && total > len(results) {
+		data.AllURL = "/?q=" + url.QueryEscape(query)
+	}
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	if err := suggestTmpl.ExecuteTemplate(w, "suggest", data); err != nil {
+		log.Printf("suggest template error: %v", err)
+	}
+}
+
+// suggestTokens lowercases query and splits it on anything that is not a
+// letter or digit.
+func suggestTokens(query string) []string {
+	return strings.FieldsFunc(strings.ToLower(query), func(r rune) bool {
+		return !unicode.IsLetter(r) && !unicode.IsNumber(r)
+	})
+}
+
+// highlightMatches bolds the first occurrence of each token in name
+// (case-insensitive), merging overlapping spans, and escapes the rest.
+func highlightMatches(name string, tokens []string) template.HTML {
+	lower := strings.ToLower(name)
+	if len(lower) != len(name) {
+		// Lowercasing changed byte lengths, so offsets would not line up.
+		return template.HTML(template.HTMLEscapeString(name))
+	}
+	type span struct{ from, to int }
+	var spans []span
+	for _, t := range tokens {
+		if i := strings.Index(lower, t); i >= 0 {
+			spans = append(spans, span{i, i + len(t)})
+		}
+	}
+	sort.Slice(spans, func(i, j int) bool { return spans[i].from < spans[j].from })
+	var b strings.Builder
+	cursor := 0
+	for i := 0; i < len(spans); i++ {
+		sp := spans[i]
+		for i+1 < len(spans) && spans[i+1].from <= sp.to {
+			i++
+			sp.to = max(sp.to, spans[i].to)
+		}
+		b.WriteString(template.HTMLEscapeString(name[cursor:sp.from]))
+		b.WriteString("<strong>" + template.HTMLEscapeString(name[sp.from:sp.to]) + "</strong>")
+		cursor = sp.to
+	}
+	b.WriteString(template.HTMLEscapeString(name[cursor:]))
+	return template.HTML(b.String())
+}
+
 // handleReindex rebuilds the folder index synchronously and returns 204.
 // The frontend reloads the page on success. Serialized via buildMu so a
 // double-click waits rather than running two walks in parallel.

suggest_test.go

@@ -0,0 +1,21 @@
+package main
+
+import "testing"
+
+func TestHighlightMatches(t *testing.T) {
+	cases := []struct{ name, query, want string }{
+		{"Project Alpha", "alpha", "Project <strong>Alpha</strong>"},
+		// Overlapping and adjacent spans merge.
+		{"Project Alpha", "pro ject", "<strong>Project</strong> Alpha"},
+		{"Project Alpha", "roj proj", "<strong>Proj</strong>ect Alpha"},
+		{"a<b>&c", "b", "a&lt;<strong>b</strong>&gt;&amp;c"},
+		{"Notes", "zzz", "Notes"},
+		// Lowercasing changes the byte length: no highlight, still escaped.
+		{"İstanbul <x>", "stan", "İstanbul &lt;x&gt;"},
+	}
+	for _, c := range cases {
+		if got := string(highlightMatches(c.name, suggestTokens(c.query))); got != c.want {
+			t.Errorf("highlightMatches(%q, %q) = %q, want %q", c.name, c.query, got, c.want)
+		}
+	}
+}

tasks.go

@@ -17,18 +17,19 @@ var taskCheckboxRe = regexp.MustCompile(`<input(?: checked="")? disabled="" type
 // then a `[ ]` / `[x]` / `[X]` checkbox marker.
 var taskLineRe = regexp.MustCompile(`^(\s*[-*+]\s+)\[([ xX])\]`)
 
-// rewriteTaskCheckboxes enables and indexes the task checkboxes in rendered
-// HTML so JS can wire them up. Each checkbox gains a data-task-index matching
-// its position among task list items in source order; the disabled attribute
-// is removed so the user can toggle them.
+// rewriteTaskCheckboxes makes the task checkboxes in rendered HTML toggle
+// their source line. The disabled attribute is removed and each checkbox
+// posts itself to ?toggle=N (htmx), N being its position among task list
+// items in source order. An unchecked box sends no value, i.e. checked=false;
+// a failed save flips the box back.
 func rewriteTaskCheckboxes(in []byte) []byte {
 	idx := 0
 	return taskCheckboxRe.ReplaceAllFunc(in, func(match []byte) []byte {
 		checked := bytes.Contains(match, []byte("checked"))
 		var out bytes.Buffer
-		out.WriteString(`<input type="checkbox" class="task-checkbox" data-task-index="`)
+		out.WriteString(`<input type="checkbox" class="task-checkbox" name="checked" value="true" hx-post="?toggle=`)
 		out.WriteString(strconv.Itoa(idx))
-		out.WriteByte('"')
+		out.WriteString(`" hx-swap="none" hx-disabled-elt="this" hx-on::response-error="this.checked = !this.checked" hx-on::send-error="this.checked = !this.checked"`)
 		if checked {
 			out.WriteString(` checked=""`)
 		}

tree.go

@@ -1,34 +1,71 @@
 package main
 
 import (
-	"encoding/json"
+	"bytes"
+	"html/template"
+	"log"
 	"net/http"
 	"os"
+	"path"
 	"path/filepath"
 	"sort"
 	"strings"
 )
 
+var treeTmpl = template.Must(template.New("tree").ParseFS(assets, "assets/tree.html"))
+
+// treeOpts selects what a folder tree renders. The same markup serves the
+// sidebar (links) and the tree picker (radio inputs named "pick").
+type treeOpts struct {
+	Files  bool   // list files, not just folders
+	Pick   string // "" renders links; "folder", "file" or "any" renders a picker for that kind
+	Active string // wiki path of the current page, highlighted (sidebar)
+	Select string // wiki path of the initially checked row (picker)
+}
+
+// query returns the ?tree query that lazy-loads a folder's children with the
+// same options.
+func (o treeOpts) query() string {
+	q := "?tree"
+	if o.Files {
+		q += "&files=1"
+	}
+	if o.Pick != "" {
+		q += "&pick=" + o.Pick
+	}
+	return q
+}
+
 type treeEntry struct {
-	Name string `json:"name"`
-	Kind string `json:"kind"`
+	Name string
+	Kind string // "folder" or "file"
 	// HasChildren reports whether a folder has any visible entries (under the
-	// same foldersOnly filter), so the client can hide the expand chevron on
-	// empty folders without a round-trip. Always false for files.
-	HasChildren bool `json:"hasChildren"`
-	// Children is populated only along the expandTo chain (see handleTree);
-	// omitted otherwise so the flat picker listing keeps its original shape.
-	Children []treeEntry `json:"children,omitempty"`
+	// same files filter), so empty folders render without a chevron.
+	HasChildren bool
 }
 
-type treeResponse struct {
-	Path    string      `json:"path"`
-	Entries []treeEntry `json:"entries"`
+// treeRow is one rendered row. Folders with children are expandable: either
+// pre-expanded (Children set, along the requested path) or lazy-loaded from
+// ChildrenURL when first opened.
+type treeRow struct {
+	Name, Path, Kind string
+	URL              string // page URL (sidebar links)
+	Link             bool   // render the name as a link
+	Selectable       bool   // render a picker radio
+	Active, Checked  bool
+	Expandable       bool
+	Children         []treeRow
+	ChildrenURL      string
 }
 
-// handleTree responds with a JSON listing of the immediate children of the
-// folder at fsPath. Hidden entries and `index.md` are filtered. Files are not
-// descended — the client lazy-loads children on expand.
+// handleTree responds with the rendered rows of the folder at fsPath:
+//
+//	?tree                   sidebar rows (folders only, links)
+//	&files=1                include files
+//	&pick=folder|file|any   picker rows selecting that kind
+//	&expandTo=/a/b          pre-expand the chain down to /a/b
+//	&select=/a/b            check that row
+//	&root=1                 lead with a row for "/" itself (picker)
 func (h *handler) handleTree(w http.ResponseWriter, r *http.Request, urlPath, fsPath string) {
 	info, err := os.Stat(fsPath)
 	if err != nil {
@@ -44,30 +81,98 @@ func (h *handler) handleTree(w http.ResponseWriter, r *http.Request, urlPath, fs
 		return
 	}
 
-	foldersOnly := r.URL.Query().Has("foldersOnly")
+	q := r.URL.Query()
+	o := treeOpts{Files: q.Has("files"), Select: q.Get("select")}
+	switch p := q.Get("pick"); p {
+	case "", "folder", "file", "any":
+		o.Pick = p
+	default:
+		http.Error(w, "bad pick mode", http.StatusBadRequest)
+		return
+	}
 
-	entries, err := listTreeEntries(fsPath, foldersOnly)
+	dir := normalizeMovePath(urlPath)
+	var expand []string
+	if segs, base := treePathSegments(q.Get("expandTo")), treePathSegments(dir); len(segs) >= len(base) &&
+		strings.Join(segs[:len(base)], "/") == strings.Join(base, "/") {
+		expand = segs[len(base):]
+	}
+	rows, err := buildTreeRows(fsPath, dir, expand, o)
 	if err != nil {
 		http.Error(w, "read failed", http.StatusInternalServerError)
 		return
 	}
-
-	if expandTo := r.URL.Query().Get("expandTo"); expandTo != "" {
-		expandTreeChain(fsPath, entries, treePathSegments(expandTo), foldersOnly)
+	if dir == "/" && q.Has("root") && o.Pick != "" {
+		root := newTreeRow(treeEntry{Name: "/", Kind: "folder"}, "/", o)
+		rows = append([]treeRow{root}, rows...)
+	}
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	if err := treeTmpl.ExecuteTemplate(w, "rows", rows); err != nil {
+		log.Printf("tree template error: %v", err)
 	}
-
-	resp := treeResponse{Path: canonicalTreePath(urlPath), Entries: entries}
-	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-	_ = json.NewEncoder(w).Encode(resp)
 }
 
-// canonicalTreePath returns the URL path in the form used by the picker:
-// "/" for root, otherwise stripped of any trailing slash.
-func canonicalTreePath(urlPath string) string {
-	if urlPath == "" || urlPath == "/" {
-		return "/"
+// sidebarTree renders the navigation tree for the page at urlPath: the root
+// listing with the chain down to the page expanded and the page highlighted.
+// The tree is part of the page itself, so the rail never paints empty.
+func sidebarTree(root, urlPath string) template.HTML {
+	page := normalizeMovePath(urlPath)
+	rows, err := buildTreeRows(root, "/", treePathSegments(page), treeOpts{Active: page})
+	if err != nil {
+		return ""
 	}
-	return "/" + strings.Trim(urlPath, "/")
+	var buf bytes.Buffer
+	if err := treeTmpl.ExecuteTemplate(&buf, "rows", rows); err != nil {
+		log.Printf("tree template error: %v", err)
+		return ""
+	}
+	return template.HTML(buf.String())
+}
+
+// buildTreeRows lists the folder fsPath (wiki path dir) and expands the
+// folder named by expand[0], recursing down the chain. The walk stops at the
+// deepest segment that still exists. Segments only ever match real directory
+// names from listTreeEntries, so this cannot traverse outside the tree.
+func buildTreeRows(fsPath, dir string, expand []string, o treeOpts) ([]treeRow, error) {
+	entries, err := listTreeEntries(fsPath, !o.Files)
+	if err != nil {
+		return nil, err
+	}
+	rows := make([]treeRow, len(entries))
+	for i, e := range entries {
+		p := path.Join(dir, e.Name)
+		rows[i] = newTreeRow(e, p, o)
+		if len(expand) > 0 && e.Kind == "folder" && e.Name == expand[0] && e.HasChildren {
+			kids, err := buildTreeRows(filepath.Join(fsPath, e.Name), p, expand[1:], o)
+			if err == nil {
+				rows[i].Children = kids
+			}
+		}
+	}
+	return rows, nil
+}
+
+func newTreeRow(e treeEntry, p string, o treeOpts) treeRow {
+	row := treeRow{
+		Name:       e.Name,
+		Path:       p,
+		Kind:       e.Kind,
+		URL:        pageURL(p),
+		Link:       o.Pick == "",
+		Active:     o.Pick == "" && p == o.Active,
+		Expandable: e.HasChildren,
+	}
+	if e.Kind == "file" {
+		row.URL = fileURL(strings.TrimPrefix(p, "/"))
+	}
+	if o.Pick != "" {
+		row.Selectable = o.Pick == "any" || o.Pick == e.Kind
+		row.Checked = row.Selectable && p == o.Select
+	}
+	if row.Expandable {
+		row.ChildrenURL = row.URL + o.query()
+	}
+	return row
 }
 
 // listTreeEntries returns the immediate children of fsPath, filtering hidden
@@ -139,28 +244,3 @@ func treePathSegments(p string) []string {
 	}
 	return segs
 }
-
-// expandTreeChain walks segs, matching each against a folder in entries by
-// name, loading that folder's children in place, and recursing. The walk stops
-// at the deepest matching segment, so a stale or deleted path simply expands as
-// far as it still exists. Segments only ever match real directory names from
-// listTreeEntries (no "." or ".." entries), so this cannot traverse outside the
-// listed tree.
-func expandTreeChain(fsPath string, entries []treeEntry, segs []string, foldersOnly bool) {
-	if len(segs) == 0 {
-		return
-	}
-	for i := range entries {
-		if entries[i].Kind != "folder" || entries[i].Name != segs[0] {
-			continue
-		}
-		childFs := filepath.Join(fsPath, segs[0])
-		kids, err := listTreeEntries(childFs, foldersOnly)
-		if err != nil {
-			return
-		}
-		entries[i].Children = kids
-		expandTreeChain(childFs, entries[i].Children, segs[1:], foldersOnly)
-		return
-	}
-}

tree_test.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestHandleTreeExpandTo(t *testing.T) {
+	root := t.TempDir()
+	for _, d := range []string{"Projects/A/Deep", "Other/B"} {
+		if err := os.MkdirAll(filepath.Join(root, filepath.FromSlash(d)), 0755); err != nil {
+			t.Fatal(err)
+		}
+	}
+	h := &handler{root: root}
+	get := func(urlPath, query string) string {
+		r := httptest.NewRequest("GET", urlPath+"?"+query, nil)
+		w := httptest.NewRecorder()
+		h.handleTree(w, r, urlPath, filepath.Join(root, filepath.FromSlash(strings.Trim(urlPath, "/"))))
+		return w.Body.String()
+	}
+
+	// A chain below the listed folder is pre-expanded.
+	if body := get("/Projects/", "tree&expandTo=/Projects/A"); !strings.Contains(body, `href="/Projects/A/Deep/"`) {
+		t.Errorf("expandTo below the folder did not expand:\n%s", body)
+	}
+	// Lazy children keep the picker options.
+	if body := get("/", "tree&pick=folder&root=1"); !strings.Contains(body, `hx-get="/Projects/?tree&pick=folder"`) ||
+		!strings.Contains(body, `value="/"`) {
+		t.Errorf("picker rows missing lazy URL or root row:\n%s", body)
+	}
+	w := httptest.NewRecorder()
+	h.handleTree(w, httptest.NewRequest("GET", "/?tree&pick=bogus", nil), "/", root)
+	if w.Code != 400 {
+		t.Errorf("bad pick mode: got %d, want 400", w.Code)
+	}
+}