[SuperEditor] Don't activate an action tag when placing the caret at an existing tag pattern. (Resolves #2392) (#2771)

Author: angelosilvestre

super_editor/lib/src/default_editor/text_tokenizing/action_tags.dart

@@ -2,6 +2,7 @@ import 'dart:math';
 
 import 'package:attributed_text/attributed_text.dart';
 import 'package:characters/characters.dart';
+import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 import 'package:super_editor/src/core/document.dart';
@@ -326,6 +327,17 @@ class ActionTagComposingReaction extends EditReaction {
       return;
     }
 
+    final hasComposingTagAttribution = textNode!.text
+        .getAttributionSpansInRange(
+          attributionFilter: (attribution) => attribution == actionTagComposingAttribution,
+          range: SpanRange(tagAroundPosition.indexedTag.startOffset, tagAroundPosition.indexedTag.endOffset),
+        )
+        .isNotEmpty;
+    if (changeList.none((event) => event is DocumentEdit) && !hasComposingTagAttribution) {
+      // The user is neither typing nor moving the caret within an existing composing tag.
+      return;
+    }
+
     _updateComposingTag(requestDispatcher, tagAroundPosition.indexedTag);
     editorContext.composingActionTag.value = tagAroundPosition.indexedTag;
     _onUpdateComposingActionTag(tagAroundPosition.indexedTag);

super_editor/test/super_editor/text_entry/tagging/action_tags_test.dart

@@ -768,6 +768,63 @@ void main() {
         // Ensure that we received a notification when the tag was cancelled.
         expect(tagNotificationCount, 7);
       });
+
+      testWidgetsOnAllPlatforms("does not start composing when placing the caret at an existing tag pattern",
+          (tester) async {
+        await _pumpTestEditor(
+          tester,
+          MutableDocument(
+            nodes: [
+              ParagraphNode(
+                id: "1",
+                text: AttributedText("This is origin/main branch"),
+              ),
+            ],
+          ),
+        );
+
+        // Place the caret at "mai|n".
+        await tester.placeCaretInParagraph("1", 18);
+
+        // Ensure that we are not composing a tag.
+        final text = SuperEditorInspector.findTextInComponent("1");
+        expect(
+          text.getAttributionSpansInRange(
+            attributionFilter: (attribution) => attribution == actionTagComposingAttribution,
+            range: const SpanRange(0, 26),
+          ),
+          isEmpty,
+        );
+      });
+
+      testWidgetsOnAllPlatforms("updates composing when moving the caret within an existing composing tag",
+          (tester) async {
+        await _pumpTestEditor(
+          tester,
+          singleParagraphEmptyDoc(),
+        );
+        await tester.placeCaretInParagraph("1", 0);
+
+        // Compose an action tag.
+        await tester.typeImeText("/header");
+
+        // Ensure that the tag has a composing attribution.
+        final textBefore = SuperEditorInspector.findTextInComponent("1");
+        expect(
+          textBefore.getAttributedRange({actionTagComposingAttribution}, 0),
+          const SpanRange(0, 6),
+        );
+
+        // Press the left arrow to move the caret within the tag.
+        await tester.pressLeftArrow();
+
+        // Ensure that the tag was updated.
+        final textAfter = SuperEditorInspector.findTextInComponent("1");
+        expect(
+          textAfter.getAttributedRange({actionTagComposingAttribution}, 0),
+          const SpanRange(0, 5),
+        );
+      });
     });
 
     group("submissions >", () {