Merge pull request #3084 from jramosg/toggle-comment-unformatted-partial-selection

Toggle comment on unformatted partial selection
Fixes #3083

Author: jramosg

CHANGELOG.md

@@ -5,6 +5,7 @@ Changes to Calva.
 ## [Unreleased]
 
 - Fix: [Toggle comments off, indent glitch](https://github.com/BetterThanTomorrow/calva/issues/3078)
+- Fix: [Toggle Line Comment can break structure for unformatted partial multiline selections](https://github.com/BetterThanTomorrow/calva/issues/3083)
 - Fix: [Clojure-lsp not starting when offline](https://github.com/BetterThanTomorrow/calva/issues/1299)
 
 ## [2.0.555] - 2026-02-19

src/edit.ts

@@ -86,6 +86,10 @@ async function applyStructuralCommentsToSingleSelectionLines(
 ) {
   const originalSelections = [...editor.selections];
   const singleSelection = editor.selections[0];
+  const partialSelectionStartColumn =
+    !singleSelection.isEmpty && affectedLineNumbers.length > 1
+      ? singleSelection.start.character
+      : undefined;
   const descendingLineNumbers = [...new Set(affectedLineNumbers)].sort((a, b) => b - a);
   const affectedLineSet = new Set(affectedLineNumbers);
   const originalFirstNonWSMap = new Map<number, number>();
@@ -137,7 +141,11 @@ async function applyStructuralCommentsToSingleSelectionLines(
           affectedLineNumbers.length > 1
             ? resolvedAlignedCommentColumn
             : originalInsertionColumnMap.get(lineNum) ?? firstNonWhitespace;
-        const insertionColumn = Math.min(rawInsertionColumn, currentLine.text.length);
+        const firstLineInsertionColumn =
+          partialSelectionStartColumn !== undefined && lineNum === singleSelection.start.line
+            ? Math.max(rawInsertionColumn, partialSelectionStartColumn)
+            : rawInsertionColumn;
+        const insertionColumn = Math.min(firstLineInsertionColumn, currentLine.text.length);
         originalInsertionColumnMap.set(lineNum, insertionColumn);
         const insertionOffset = editor.document.offsetAt(
           new vscode.Position(lineNum, insertionColumn)

src/extension-test/integration/suite/toggle-comment-test.ts

@@ -281,6 +281,20 @@ suite(suiteName, () => {
     );
   });
 
+  it('should structurally comment unformatted multiline partial selection in a defn body', async () => {
+    assert.equal(
+      await toggleCommentUsingActiveEditor('(defn foo []•(a |(b c•d•e)|•f))'),
+      '(defn foo []•(a |;; (b c•;; d•;; e)|•f))'
+    );
+  });
+
+  it('should structurally comment unformatted nested multiline partial selection without breaking structure', async () => {
+    assert.equal(
+      await toggleCommentUsingActiveEditor('(defn foo []•(a |(b c•(d e•f)•g•h)|•i•j))'),
+      '(defn foo []•(a |;; (b c•;; (d e•;; f)•;; g•;; h)|•i•j))'
+    );
+  });
+
   it('should structurally comment multiline selection nested in parent form and preserve full selected range', async () => {
     assert.equal(
       await toggleCommentUsingActiveEditor('(x•  (y |(a b•        c)|)•  z)'),