Keep Agent Mode session titles consistent across tabs and history

docs/agent-mode-and-tools.md

@@ -141,6 +141,7 @@ Agent Chat keeps each conversation separate:
 - Select **New Chat** to reset the current tab.
 - Select **Stop** to cancel the current turn. Queued follow-ups return to the message box, with their notes, web pages, agent mentions, and images, so you can edit or resend them. Queued content comes before the current draft, and custom commands return as their expanded text.
 - Use **Recent Chats** from the Agent Chat home screen, or **Chat History** inside a conversation, to resume saved work. The **Recent Chats** list can be scrolled or searched.
+- Rename a session from its tab or history list to give it a meaningful title. The same title appears in both places when you reopen the chat.
 - Select **Copy Chat Link** beside **New Chat** to copy an `obsidian://` link to the current conversation. Paste it into another note to reopen the chat in the same vault. A saved conversation stays linked after its Markdown note is renamed; a conversation stored only by its agent can be linked once the agent has a session ID.
 - A spinner marks a chat while its agent is responding. When the response stops but the session remains live, a small blue dot appears on the bottom-right corner of the chat icon. Hover the row and select **Close session** to release that session. Saved history stays available to reopen, and other chats keep running. If the agent does not support closing individual sessions or release fails, the chat stays marked live with an error.
 - Add the active note, selected text, other notes, folders, a Copilot Web Viewer tab, or supported images. You can also mention a note with `[[Note title]]`.

src/agentMode/session/AgentChatPersistenceManager.test.ts

@@ -1,6 +1,6 @@
 /* eslint-disable obsidianmd/no-tfile-tfolder-cast -- test fixtures; not real TFiles */
 import { AI_SENDER, USER_SENDER } from "@/constants";
-import { readFrontmatterViaAdapter } from "@/utils/vaultAdapterUtils";
+import { patchFrontmatter } from "@/utils/vaultAdapterUtils";
 import { AgentChatPersistenceManager } from "./AgentChatPersistenceManager";
 import { GLOBAL_SCOPE } from "./scope";
 import type { AgentChatMessage } from "./types";
@@ -13,6 +13,7 @@ jest.mock("obsidian", () => ({
   normalizePath: (path: string) => path,
   Notice: jest.fn(),
   TFile: jest.fn(),
+  parseYaml: (content: string) => jest.requireActual("yaml").parse(content),
 }));
 jest.mock("@/logger");
 jest.mock("@/settings/model", () => ({
@@ -42,7 +43,7 @@ jest.mock("@/utils", () => ({
 jest.mock("@/utils/vaultAdapterUtils", () => ({
   isInVaultCache: jest.fn(() => false),
   listMarkdownFiles: jest.fn().mockResolvedValue([]),
-  readFrontmatterViaAdapter: jest.fn().mockResolvedValue(null),
+  patchFrontmatter: jest.fn(),
 }));
 
 interface FakeFile {
@@ -130,7 +131,124 @@ describe("AgentChatPersistenceManager", () => {
     manager = new AgentChatPersistenceManager(app as unknown as App);
   });
 
+  describe("loadFile()", () => {
+    it.each([
+      ["a folded title", ""],
+      ["a BOM-prefixed folded title", "\uFEFF"],
+    ])(
+      "reopens %s with its original transcript https://github.com/logancyang/obsidian-copilot/issues/3378",
+      async (_case, prefix) => {
+        const saved = await manager.saveSession(
+          [makeMessage(USER_SENDER, "Original prompt")],
+          "opencode",
+          { label: "Useful workflow" }
+        );
+        const file = app.files.get(saved!.path)!;
+        file.contents =
+          prefix + file.contents!.replace("---\n", "---\ntopic: >-\n  Useful\n  workflow\n");
+
+        const loaded = await manager.loadFile(file as unknown as TFile);
+
+        expect(loaded.topic).toBe("Useful workflow");
+        expect(loaded.label).toBe("Useful workflow");
+        expect(loaded.messages.map((message) => message.message)).toEqual(["Original prompt"]);
+      }
+    );
+  });
+
   describe("saveSession()", () => {
+    it("preserves a BOM-prefixed note's title and recency during autosave https://github.com/logancyang/obsidian-copilot/issues/3378", async () => {
+      const messages = [makeMessage(USER_SENDER, "Original prompt")];
+      const saved = await manager.saveSession(messages, "opencode");
+      const file = app.files.get(saved!.path)!;
+      Object.setPrototypeOf(file, TFile.prototype);
+      file.contents =
+        "\uFEFF" +
+        file.contents!.replace("---\n", '---\ntopic: "Useful workflow"\nlastAccessedAt: 123456\n');
+      app.metadataCache.getFileCache.mockReturnValue({
+        frontmatter: { topic: "Useful workflow", lastAccessedAt: 123456 },
+      } as never);
+
+      await manager.saveSession(messages, "opencode", { existingPath: saved!.path });
+
+      expect(file.contents).toContain('topic: "Useful workflow"');
+      expect(file.contents).toContain("lastAccessedAt: 123456");
+    });
+
+    it("preserves a valid folded YAML title during autosave https://github.com/logancyang/obsidian-copilot/issues/3378", async () => {
+      const messages = [makeMessage(USER_SENDER, "Original prompt")];
+      const saved = await manager.saveSession(messages, "opencode");
+      const file = app.files.get(saved!.path)!;
+      Object.setPrototypeOf(file, TFile.prototype);
+      file.contents = file.contents!.replace("---\n", "---\ntopic: >-\n  Useful\n  workflow\n");
+      app.metadataCache.getFileCache.mockReturnValue({
+        frontmatter: { topic: "Useful workflow" },
+      } as never);
+
+      await manager.saveSession(messages, "opencode", { existingPath: saved!.path });
+
+      expect(file.contents).toContain('topic: "Useful workflow"');
+    });
+
+    it("keeps a renamed title when metadata cache lags the next save https://github.com/logancyang/obsidian-copilot/issues/3378", async () => {
+      const messages = [makeMessage(USER_SENDER, "Original prompt")];
+      const saved = await manager.saveSession(messages, "opencode", { label: "Old label" });
+      const file = app.files.get(saved!.path)!;
+      Object.setPrototypeOf(file, TFile.prototype);
+      file.contents = file.contents!.replace("---\n", '---\ntopic: "Current title"\n');
+      app.metadataCache.getFileCache.mockReturnValue({
+        frontmatter: { topic: "Old title", agentLabel: "Old label" },
+      } as never);
+
+      await manager.saveSession(messages, "opencode", {
+        existingPath: saved!.path,
+        label: "Current title",
+      });
+
+      expect(file.contents).toContain('topic: "Current title"');
+      expect(file.contents).toContain('agentLabel: "Current title"');
+    });
+
+    it("keeps the latest tab rename after an in-flight autosave and reload https://github.com/logancyang/obsidian-copilot/issues/3378", async () => {
+      const messages = [makeMessage(USER_SENDER, "Original prompt")];
+      const saved = await manager.saveSession(messages, "opencode", { label: "Alpha" });
+      const file = app.files.get(saved!.path)!;
+      Object.setPrototypeOf(file, TFile.prototype);
+      file.contents = file.contents!.replace("---\n", '---\ntopic: "Alpha"\n');
+      let finishRead!: (content: string) => void;
+      let readStarted!: () => void;
+      const started = new Promise<void>((resolve) => (readStarted = resolve));
+      app.vault.adapter.read.mockImplementationOnce(
+        () =>
+          new Promise((resolve) => {
+            finishRead = resolve;
+            readStarted();
+          })
+      );
+      (patchFrontmatter as jest.Mock).mockImplementationOnce(async (_app, path, updates) => {
+        const target = app.files.get(path)!;
+        target.contents = target.contents!.replace(/^topic:.*$/m, `topic: "${updates.topic}"`);
+      });
+
+      const saving = manager.saveSession(messages, "opencode", {
+        existingPath: saved!.path,
+        label: "Alpha",
+      });
+      await started;
+      const renaming = manager.updateTopic(saved!.path, "Beta");
+      expect(patchFrontmatter).not.toHaveBeenCalled();
+      finishRead(file.contents);
+      await saving;
+      await renaming;
+      await manager.saveSession(messages, "opencode", {
+        existingPath: saved!.path,
+        label: "Beta",
+      });
+
+      const loaded = await manager.loadFile(file as unknown as TFile);
+      expect(loaded.topic).toBe("Beta");
+      expect(loaded.label).toBe("Beta");
+    });
     it("preserves organizer links after native rehydration, reopening and later deletion (https://github.com/Brevilabs/obsidian-copilot-private/issues/533)", async () => {
       const message = {
         ...makeMessage(USER_SENDER, "image"),
@@ -433,12 +551,6 @@ describe("AgentChatPersistenceManager", () => {
   });
 
   describe("usage frontmatter", () => {
-    afterEach(() => {
-      // Restore the default no-metadata behavior for the adapter helper so a
-      // per-test override (round-trip-on-omit) doesn't leak into other suites.
-      (readFrontmatterViaAdapter as jest.Mock).mockResolvedValue(null);
-    });
-
     it("round-trips a SessionUsage snapshot through save/load", async () => {
       const messages = [makeMessage(USER_SENDER, "hi")];
       const usage = {
@@ -466,21 +578,6 @@ describe("AgentChatPersistenceManager", () => {
       // the mocked prototype so the resave takes the existing-file path (where
       // usage round-trips) instead of treating it as a brand-new write.
       Object.setPrototypeOf(app.files.get(first!.path)!, TFile.prototype);
-      // Mirror production: `readExistingMeta` reads the prior file's frontmatter
-      // to round-trip fields the caller didn't re-supply. The default mock
-      // returns null (no metadata), so parse the stored file here — quote-strip
-      // matches the real adapter helper so the JSON value comes back intact.
-      (readFrontmatterViaAdapter as jest.Mock).mockImplementation(async (_app, path: string) => {
-        const raw = app.files.get(path)?.contents ?? "";
-        const yaml = raw.match(/^---\n([\s\S]*?)\n---/)?.[1];
-        if (!yaml) return null;
-        const fm: Record<string, string> = {};
-        for (const line of yaml.split("\n")) {
-          const m = line.match(/^([\w-]+):\s*(.+)/);
-          if (m) fm[m[1]] = m[2].trim().replace(/^["']|["']$/g, "");
-        }
-        return fm;
-      });
       // A save with no usage option must not drop the stored snapshot.
       const second = await manager.saveSession(messages, "claude", {
         existingPath: first!.path,