From fa0d37bf4170582a6b8b5276487caf79aa1ced73 Mon Sep 17 00:00:00 2001
From: Alex Southwell <4596216+saphid@users.noreply.github.com>
Date: Tue, 3 Nov 2026 11:22:20 +1100
Subject: [PATCH] fix(shared): find in thread matches a word typed with a curly
 apostrophe

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 packages/shared/src/threadSearch.test.ts | 5 +++++
 packages/shared/src/threadSearch.ts      | 7 +++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/packages/shared/src/threadSearch.test.ts b/packages/shared/src/threadSearch.test.ts
index 83b87841c789a..fb52b2ec16a29 100644
--- a/packages/shared/src/threadSearch.test.ts
+++ b/packages/shared/src/threadSearch.test.ts
@@ -12,3 +12,8 @@ it("matches both Greek sigma forms without changing source offsets", () => {
   expect(findThreadSearchOccurrences("ΟΣ ος οσ", "ς")).toEqual([1, 4, 7]);
   expect(findThreadSearchOccurrences("İ ΟΣ", "Σ")).toEqual([3]);
 });
+
+it("matches straight and curly apostrophes without changing source offsets", () => {
+  expect(findThreadSearchOccurrences("don't don’t", "don’t")).toEqual([0, 6]);
+  expect(findThreadSearchOccurrences("İ don‘t", "don't")).toEqual([2]);
+});
diff --git a/packages/shared/src/threadSearch.ts b/packages/shared/src/threadSearch.ts
index 5cca036d7bed4..6ffa12fcc1523 100644
--- a/packages/shared/src/threadSearch.ts
+++ b/packages/shared/src/threadSearch.ts
@@ -1,10 +1,13 @@
+// A typed straight apostrophe finds a curly one: iOS keyboards type "’".
+const foldCharacters = (text: string) => text.replace(/ς/g, "σ").replace(/[‘’]/g, "'");
+
 function foldThreadSearchCase(text: string): string {
-  const lowered = text.toLowerCase().replace(/ς/g, "σ");
+  const lowered = foldCharacters(text.toLowerCase());
   if (lowered.length === text.length) return lowered;
 
   let folded = "";
   for (const character of text) {
-    const loweredCharacter = character.toLowerCase().replace(/ς/g, "σ");
+    const loweredCharacter = foldCharacters(character.toLowerCase());
     folded += loweredCharacter.length === character.length ? loweredCharacter : character;
   }
   return folded;