test: verify folder dialog listener cleanup

tests/favorite-folder-dialog.test.ts

@@ -1,6 +1,6 @@
 // @vitest-environment jsdom
 
-import { beforeEach, describe, expect, test } from "vitest";
+import { beforeEach, describe, expect, test, vi } from "vitest";
 
 import { promptForFavoriteFolderName } from "../src/content/market/favorite-folder-dialog";
 
@@ -146,31 +146,34 @@ describe("favorite-folder-dialog", () => {
     await expect(second).resolves.toBeNull();
   });
 
-  test("removes a closed dialog keydown listener before a fresh dialog opens", async () => {
-    let firstSettlementCount = 0;
-    const first = promptForFavoriteFolderName(document, {
-      title: "新建收藏夹"
-    });
-    void first.then(() => {
-      firstSettlementCount += 1;
-    });
+  test("removes the exact captured document keydown listener when closed", async () => {
+    const addEventListener = vi.spyOn(document, "addEventListener");
+    const removeEventListener = vi.spyOn(document, "removeEventListener");
 
-    readButton("cancel").click();
-    await expect(first).resolves.toBeNull();
-    await Promise.resolve();
-    expect(firstSettlementCount).toBe(1);
+    try {
+      const result = promptForFavoriteFolderName(document, {
+        title: "新建收藏夹"
+      });
+      const keydownRegistration = addEventListener.mock.calls.find(
+        (call) => call[0] === "keydown" && call[2] === true
+      );
+      if (!keydownRegistration) {
+        throw new Error("Expected a captured keydown listener");
+      }
+      const keydownHandler = keydownRegistration[1];
 
-    const current = promptForFavoriteFolderName(document, {
-      title: "重命名收藏夹"
-    });
-    document.dispatchEvent(new KeyboardEvent("keydown", { key: "Escape" }));
+      readButton("cancel").click();
+      await expect(result).resolves.toBeNull();
 
-    await expect(current).resolves.toBeNull();
-    await Promise.resolve();
-    expect(firstSettlementCount).toBe(1);
-    expect(
-      document.querySelector('[data-sces-favorite-folder-dialog="root"]')
-    ).toBeNull();
+      expect(removeEventListener).toHaveBeenCalledWith(
+        "keydown",
+        keydownHandler,
+        true
+      );
+    } finally {
+      addEventListener.mockRestore();
+      removeEventListener.mockRestore();
+    }
   });
 
   test("traps Tab within the dialog and restores the opener focus on close", async () => {