Add fail templates

tests/tests.nim

@@ -3,66 +3,89 @@
 import unittest
 import op
 
-test "Check OK":
-  let test = ok 1
-  check test.isOk == true
+suite "Basic tests":
+  test "Check OK":
+    let test = ok 1
+    check test.isOk == true
 
-test "Check fail":
-  let test = op.fail[int] "no data here"
-  check test.isOk == false
+  test "Check fail":
+    let test = fail(void, "no data here")
+    check test.isOk == false
 
-test "Check proc results":
-  proc createValue: OP[string] =
-    let myString = "This is test code!"
-    ok myString
-  let data = createValue()
-  check data.isOk
-  check data.val == "This is test code!"
+  test "Check proc results":
+    proc createValue: OP[string] =
+      let myString = "This is test code!"
+      ok myString
+    let data = createValue()
+    check data.isOk
+    check data.val == "This is test code!"
 
-test "Check failing result proc":
-  proc someProc(): OP[int] =
-    result.fail "Not implemented!"
+  test "Check failing result proc":
+    proc someProc(): OP[int] =
+      result.fail "Not implemented!"
 
-  let data = someProc()
-  assert data.isOk == false
-  assert data.error == "Not implemented!"
+    let data = someProc()
+    assert data.isOk == false
+    assert data.error == "Not implemented!"
 
-test "Check failing typedesc proc ":
-  proc someProc(): OP[int] =
-    fail(int, "Not implemented!")
+  test "Check failing typedesc proc ":
+    proc someProc(): OP[int] =
+      op.fail(int, "Not implemented!")
 
-  let data = someProc()
-  assert data.isOk == false
-  assert data.error == "Not implemented!"
+    let data = someProc()
+    assert data.isOk == false
+    assert data.error == "Not implemented!"
 
-test "Check failing type param proc ":
-  proc someProc(): OP[int] =
-    op.fail[int]("Not implemented!")
+  test "Check failing type param proc ":
+    proc someProc(): OP[int] =
+      fail(int, "Not implemented!")
 
-  let data = someProc()
-  assert data.isOk == false
-  assert data.error == "Not implemented!"
+    let data = someProc()
+    assert data.isOk == false
+    assert data.error == "Not implemented!"
 
-test "Check changing result":
-  proc checker(): OP[int] =
-    result = ok 42
-    # something happend here
-    result = result.fail "data got corrupted"
+  test "Check changing result":
+    proc checker(): OP[int] =
+      result = ok 42
+      # something happend here
+      result = result.fail "data got corrupted"
 
-  let data = checker()
-  check data.isOk == false
-  check data.error == "data got corrupted"
+    let data = checker()
+    check data.isOk == false
+    check data.error == "data got corrupted"
 
-test "Check divider proc":
-  proc divide(a, b: int): OP[float] =
-    if b == 0:
-      return fail(float, "Cannot divide by zero!")
-    else:
-      return ok a / b
+  test "Check divider proc":
+    proc divide(a, b: int): OP[float] =
+      if b == 0:
+        return fail(float, "Cannot divide by zero!")
+      else:
+        return ok a / b
 
-  let
-    a = 42
-    b = 0
-  let r = divide(a, b)
-  check r.isOk == false
-  check r.error == "Cannot divide by zero!"
+    let
+      a = 42
+      b = 0
+    let r = divide(a, b)
+    check r.isOk == false
+    check r.error == "Cannot divide by zero!"
+
+  test "Check implicit fail type":
+    proc divide(a, b: int): OP[float] =
+      if b == 0:
+        return fail "Cannot divide by zero!"
+      else:
+        return ok a / b
+
+    let r = divide(1, 0)
+    check r.isOk == false
+    check r.error == "Cannot divide by zero!"
+
+  test "Check type of impolicit fail":
+      proc divide(a, b: int): OP[float] =
+        if b == 0:
+          return fail "Cannot divide by zero!"
+        else:
+          return ok a / b
+
+      let r = divide(1, 0)
+      check r.isOk == false
+      check r.error == "Cannot divide by zero!"