fix: preserve punctuation when removing completion tags

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 #### Review fixes
 
+- Preserved punctuation immediately before a completion or elapsed-time tag when reopening a task.
 - Rejected invalid ISO calendar dates in time estimates instead of silently rolling them into another month.
 - Ignored empty relative file links wrapped in punctuation or spelled with dot path segments, instead of linking to the Todo document's directory.
 - Kept tag cleanup and hidden-tag labels working after an unmatched backtick, while preserving tags inside complete inline code spans.

src/utils/todo-status.ts

@@ -59,5 +59,9 @@ export const removeTodoStatusTag = (text: string, pattern: RegExp): string => {
 
   if (!match) return text;
 
-  return text.slice(0, match.index) + text.slice(match.index + match[0].length);
+  // The tag-boundary regex includes the character before @. Keep punctuation,
+  // but consume the separating whitespace as before.
+  const boundary = match[0][0];
+  const prefix = boundary !== '@' && !/\s/.test(boundary) ? boundary : '';
+  return text.slice(0, match.index) + prefix + text.slice(match.index + match[0].length);
 };

test/todo-status.spec.ts

@@ -39,4 +39,13 @@ describe('Todo status matching', () => {
     );
     expect(removeTodoStatusTag('☐ Explain `@done`', tagFinished)).to.equal('☐ Explain `@done`');
   });
+
+  it('preserves punctuation before status tags when unfinishing tasks', () => {
+    const tagFinished = /(?:^|[^a-zA-Z0-9])@(?:done|cancelled)(?:\([^)]*\))?/;
+    const tagElapsed = /(?:^|[^a-zA-Z0-9])@(?:lasted|wasted)(?:\([^)]*\))?/;
+
+    expect(removeTodoStatusTag('☐ Ship,@done', tagFinished)).to.equal('☐ Ship,');
+    expect(removeTodoStatusTag('☐ Ship!@cancelled(reason)', tagFinished)).to.equal('☐ Ship!');
+    expect(removeTodoStatusTag('☐ Ship,@lasted(2h)', tagElapsed)).to.equal('☐ Ship,');
+  });
 });