From a2682de4214cd277089fbf4a4c848d57a967f76d Mon Sep 17 00:00:00 2001
From: Julius Marminge <julius0216@outlook.com>
Date: Thu, 5 Mar 2026 10:43:11 -0800
Subject: [PATCH] Use mention adjacency helper in composer onChange

- replace Lexical-node cursor adjacency check with text/cursor helper
- prevent `@query` typing from being treated as mention-pill adjacent
- add regression test for non-pill `@pac` input
---
 .../src/components/ComposerPromptEditor.tsx   | 28 +++----------------
 apps/web/src/composer-logic.test.ts           |  6 ++++
 2 files changed, 10 insertions(+), 24 deletions(-)

diff --git a/apps/web/src/components/ComposerPromptEditor.tsx b/apps/web/src/components/ComposerPromptEditor.tsx
index 6795d0535cb1784670a24589c71a878d8f86cea4..2c089dab011e9a4ae78278363bc6f2aada7bbfc4 100644
--- a/apps/web/src/components/ComposerPromptEditor.tsx
+++ b/apps/web/src/components/ComposerPromptEditor.tsx
@@ -558,29 +558,6 @@ function ComposerMentionSelectionNormalizePlugin() {
   return null;
 }
 
-function $isCursorAdjacentToMention(): boolean {
-  const selection = $getSelection();
-  if (!$isRangeSelection(selection) || !selection.isCollapsed()) return false;
-  const anchorNode = selection.anchor.getNode();
-
-  if (anchorNode instanceof ComposerMentionNode) return true;
-
-  if ($isElementNode(anchorNode)) {
-    const childIndex = selection.anchor.offset - 1;
-    if (childIndex >= 0) {
-      const child = anchorNode.getChildAtIndex(childIndex);
-      if (child instanceof ComposerMentionNode) return true;
-    }
-  }
-
-  if ($isTextNode(anchorNode) && selection.anchor.offset === 0) {
-    const prev = anchorNode.getPreviousSibling();
-    if (prev instanceof ComposerMentionNode) return true;
-  }
-
-  return false;
-}
-
 function ComposerMentionBackspacePlugin() {
   const [editor] = useLexicalComposerContext();
 
@@ -756,7 +733,10 @@ function ComposerPromptEditorInner({
         value: nextValue,
         cursor: nextCursor,
       };
-      onChangeRef.current(nextValue, nextCursor, $isCursorAdjacentToMention());
+      const cursorAdjacentToMention =
+        isCollapsedCursorAdjacentToMention(nextValue, nextCursor, "left") ||
+        isCollapsedCursorAdjacentToMention(nextValue, nextCursor, "right");
+      onChangeRef.current(nextValue, nextCursor, cursorAdjacentToMention);
     });
   }, []);
 
diff --git a/apps/web/src/composer-logic.test.ts b/apps/web/src/composer-logic.test.ts
index 57e044186b464fd8df4e12047c8bda53a493e103..b9990d7fdfd3b8fd977ab761bbb39604e6ca29d1 100644
--- a/apps/web/src/composer-logic.test.ts
+++ b/apps/web/src/composer-logic.test.ts
@@ -85,6 +85,12 @@ describe("isCollapsedCursorAdjacentToMention", () => {
     expect(isCollapsedCursorAdjacentToMention("plain text", 6, "right")).toBe(false);
   });
 
+  it("keeps @query typing non-adjacent while no mention pill exists", () => {
+    const text = "hello @pac";
+    expect(isCollapsedCursorAdjacentToMention(text, text.length, "left")).toBe(false);
+    expect(isCollapsedCursorAdjacentToMention(text, text.length, "right")).toBe(false);
+  });
+
   it("detects left adjacency only when cursor is directly after a mention", () => {
     const text = "open @AGENTS.md next";
     const mentionStart = "open ".length;
-- 
2.54.0