adding some tests of the editor

Author: grantnelson-wf

playground/internal/editor/editor.go

@@ -70,6 +70,14 @@ func (ce *codeEditor) handleTab(shift, ctrl bool) bool {
 		return true
 	}
 
+	startLine, endLine := ce.getSelectedLines()
+	containsOnlyBlankLines := ce.foreachLine(startLine, endLine,
+		func(line string, start, end int) bool { return trimLeftSpace(line) == `` })
+	if containsOnlyBlankLines {
+		// Nothing to indent or un-indent.
+		return true
+	}
+
 	if shift {
 		// Handle Shift+Tab for un-indenting the current line.
 		// TODO(grantnelson-wf): Implement
@@ -149,72 +157,95 @@ func (ce *codeEditor) handleSave(shift, ctrl bool) bool {
 	return true
 }
 
+const commentPrefix = `// `
+
 // handleCommentToggle handles toggling comments on the current line or selection.
 func (ce *codeEditor) handleCommentToggle(shift, ctrl bool) bool {
 	if !ctrl || shift {
 		// Allow default behavior for '/' without a Ctrl or Shift+/.
 		return false
 	}
 
-	const commentPrefix = `// `
-
 	startLine, endLine := ce.getSelectedLines()
-	leastIndent := -1
-	nonBlankLineCount := 0
+	containsOnlyBlankLines := true
+	containsUncommentedLine := false
 	ce.foreachLine(startLine, endLine, func(line string, start, end int) bool {
 		if trimmed := trimLeftSpace(line); trimmed != `` {
-			indent := len(line) - len(trimmed)
-			if leastIndent < 0 || indent < leastIndent {
-				leastIndent = indent
+			containsOnlyBlankLines = false
+			if !strings.HasPrefix(trimmed, commentPrefix) {
+				containsUncommentedLine = true
+				return false
 			}
-			nonBlankLineCount++
 		}
 		return true
 	})
 
-	if nonBlankLineCount <= 0 {
-		// No non-blank lines, nothing to comment/uncomment.
+	if containsOnlyBlankLines {
+		// Nothing to comment or uncomment.
 		return true
 	}
 
-	containsUncommentedLine := false
+	if containsUncommentedLine {
+		ce.addCommenting(startLine, endLine)
+		return true
+	}
+
+	ce.removeCommenting(startLine, endLine)
+	return true
+}
+
+// addCommenting will add the comment prefix to each non-blank line in
+// the given range including any lines that already are commented.
+func (ce *codeEditor) addCommenting(startLine, endLine int) {
+	leastIndent := -1
 	ce.foreachLine(startLine, endLine, func(line string, start, end int) bool {
-		trimmed := strings.TrimSpace(line)
-		if trimmed != `` && !strings.HasPrefix(trimmed, commentPrefix) {
-			containsUncommentedLine = true
+		if trimmed := trimLeftSpace(line); trimmed != `` {
+			if indent := len(line) - len(trimmed); leastIndent < 0 || indent < leastIndent {
+				leastIndent = indent
+			}
 		}
 		return true
 	})
 
-	if containsUncommentedLine {
-		// Comment the selected lines including any commented lines.
-		code := ce.Code()[:startLine]
-		ce.foreachLine(startLine, endLine, func(line string, start, end int) bool {
-			if line == "\n" || strings.TrimSpace(line) == `` {
-				code += line // Empty line, just add as-is.
-				return true
-			}
-			code += line[:leastIndent] + commentPrefix + line[leastIndent:]
+	selStart, selEnd := ce.GetSelection()
+	newStart, newEnd := selStart, selEnd
+	code := ce.Code()[:startLine]
+	ce.foreachLine(startLine, endLine, func(line string, start, end int) bool {
+		if strings.TrimSpace(line) == `` {
+			code += line // Empty line, just add as-is.
 			return true
-		})
-		code += ce.Code()[endLine:]
-
-		start, end := ce.GetSelection()
-		// TODO(grantnelson-wf): Handle when the end or start ends up before the comment prefix.
-		newStart := start + len(commentPrefix)
-		newEnd := end + len(commentPrefix)*nonBlankLineCount
-
-		ce.SetCode(code)
-		ce.SetSelection(newStart, newEnd, code)
+		}
+		if selStart > start+leastIndent {
+			newStart += len(commentPrefix)
+		}
+		if selEnd > start+leastIndent {
+			newEnd += len(commentPrefix)
+		}
+		code += line[:leastIndent] + commentPrefix + line[leastIndent:]
 		return true
-	}
+	})
+	code += ce.Code()[endLine:]
+
+	ce.SetCode(code)
+	ce.SetSelection(newStart, newEnd, code)
+}
 
-	// Uncomment any line that starts with the comment prefix (and preceding whitespace).
+// removeCommenting will uncomment any line that starts with the comment prefix
+// (and preceding whitespace).
+func (ce *codeEditor) removeCommenting(startLine, endLine int) {
+	selStart, selEnd := ce.GetSelection()
+	newStart, newEnd := selStart, selEnd
 	code := ce.Code()[:startLine]
 	ce.foreachLine(startLine, endLine, func(line string, start, end int) bool {
 		if trimmed := trimLeftSpace(line); trimmed != `` {
 			if index := strings.Index(line, commentPrefix); index >= 0 {
 				code += line[:index] + line[index+len(commentPrefix):]
+				if selStart > start+index {
+					newStart -= len(commentPrefix)
+				}
+				if selEnd > start+index {
+					newEnd -= len(commentPrefix)
+				}
 				return true
 			}
 		}
@@ -223,14 +254,8 @@ func (ce *codeEditor) handleCommentToggle(shift, ctrl bool) bool {
 	})
 	code += ce.Code()[endLine:]
 
-	start, end := ce.GetSelection()
-	// TODO(grantnelson-wf): Handle when the end or start ends up before the comment prefix.
-	newStart := start - len(commentPrefix)
-	newEnd := end - len(commentPrefix)*nonBlankLineCount
-
 	ce.SetCode(code)
 	ce.SetSelection(newStart, newEnd, code)
-	return true
 }
 
 // getSelectedLines returns the start and end character indices of that
@@ -246,7 +271,7 @@ func (ce *codeEditor) getSelectedLines() (int, int) {
 	startLine := 0
 	if start >= 0 && start <= codeLen {
 		startLine = strings.LastIndex(code[:start], "\n") + 1
-		if startLine < 0 {
+		if startLine <= 0 {
 			startLine = 0
 		}
 	}

playground/internal/editor/editor_test.go

@@ -49,6 +49,8 @@ func Test_Editor_ProcessKeyDown_Tab(t *testing.T) {
 	// TODO: Add more tests for other Tab cases.
 }
 
+// TODO(grantnelson-wf): Add tests for findMatchingOpeningBrace
+
 func Test_Editor_ProcessKeyDown_Newline(t *testing.T) {
 	runKeyDownTest(t, testKeyDown{
 		name:               `with ctrl does default`,
@@ -447,7 +449,7 @@ func Test_Editor_ProcessKeyDown_CommentToggle(t *testing.T) {
 	})
 
 	runKeyDownTest(t, testKeyDown{
-		name: `remove comments`,
+		name: `uncomment lines`,
 		code: lines(
 			`func main() {`,
 			`	// // The following is always true`,
@@ -473,7 +475,114 @@ func Test_Editor_ProcessKeyDown_CommentToggle(t *testing.T) {
 		wantPrefentDefault: true,
 	})
 
-	// TODO(grantnelson-wf): Add more tests
+	runKeyDownTest(t, testKeyDown{
+		name: `uncomment with blank line`,
+		code: lines(
+			`func main() {`,
+			`	// if true {`,
+			`		`,
+			`	// 	fmt.Println("Hello")`,
+			`	}`,
+			`}`),
+		key:            `/`,
+		ctrl:           true,
+		selectionStart: 21, // before `true`
+		selectionEnd:   39, // after `fmt`
+		wantCode: lines(
+			`func main() {`,
+			`	if true {`,
+			`		`,
+			`		fmt.Println("Hello")`,
+			`	}`,
+			`}`),
+		wantSelectionStart: 18, // selection adjusted for removed `// `s
+		wantSelectionEnd:   33,
+		wantPrefentDefault: true,
+	})
+
+	runKeyDownTest(t, testKeyDown{
+		name: `comment caret`,
+		code: lines(
+			`func main() {`,
+			`	fmt.Println("Hello")`,
+			`}`),
+		key:            `/`,
+		ctrl:           true,
+		selectionStart: 18, // after `fmt`
+		selectionEnd:   18,
+		wantCode: lines(
+			`func main() {`,
+			`	// fmt.Println("Hello")`,
+			`}`),
+		wantSelectionStart: 21, // selection adjusted for added `// `s
+		wantSelectionEnd:   21,
+		wantPrefentDefault: true,
+	})
+
+	runKeyDownTest(t, testKeyDown{
+		name: `uncomment caret`,
+		code: lines(
+			`func main() {`,
+			`	// fmt.Println("Hello")`,
+			`}`),
+		key:            `/`,
+		ctrl:           true,
+		selectionStart: 21, // after `fmt`
+		selectionEnd:   21,
+		wantCode: lines(
+			`func main() {`,
+			`	fmt.Println("Hello")`,
+			`}`),
+		wantSelectionStart: 18, // selection adjusted for removed `// `s
+		wantSelectionEnd:   18,
+		wantPrefentDefault: true,
+	})
+
+	runKeyDownTest(t, testKeyDown{
+		name: `comment only moves selection if after changes`,
+		code: lines(
+			`func main() {`,
+			`	if true {`,
+			`		fmt.Println("Hello")`,
+			`	}`,
+			`}`),
+		key:            `/`,
+		ctrl:           true,
+		selectionStart: 14, // at front of line 2
+		selectionEnd:   48, // at front of line 4
+		wantCode: lines(
+			`func main() {`,
+			`	// if true {`,
+			`	// 	fmt.Println("Hello")`,
+			`	// }`,
+			`}`),
+		wantSelectionStart: 14, // before added `// `s
+		wantSelectionEnd:   54, // before last added `// `s
+		wantPrefentDefault: true,
+	})
+
+	runKeyDownTest(t, testKeyDown{
+		name: `uncomment only moves selection if after changes`,
+		code: lines(
+			`func main() {`,
+			`	// if true {`,
+			`	// 	fmt.Println("Hello")`,
+			`	// }`,
+			`}`),
+		key:            `/`,
+		ctrl:           true,
+		selectionStart: 14, // at front of line 2
+		selectionEnd:   54, // at front of line 4
+		wantCode: lines(
+			`func main() {`,
+			`	if true {`,
+			`		fmt.Println("Hello")`,
+			`	}`,
+			`}`),
+		wantSelectionStart: 14, // before added `// `s
+		wantSelectionEnd:   48, // before last added `// `s
+		wantPrefentDefault: true,
+	})
 }
 
 func Test_Editor_ProcessKeyDown_Callback(t *testing.T) {