test(FN-4927): cover no-task fallback for task tools

Fusion-Task-Id: FN-4927
Fusion-Task-Lineage: 8ef39a69-8f1f-4ffe-9d6b-1b752756751d

packages/cli/src/__tests__/extension-task-tools.test.ts

@@ -1,28 +1,45 @@
-import { describe, expect, it, vi } from "vitest";
+import { describe, expect, it, vi, beforeEach, afterEach } from "vitest";
 import { mkdtemp, mkdir, rm } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import kbExtension from "../extension.js";
-import { TaskStore } from "@fusion/core";
+import { TaskStore, getProjectRootFromWorktree } from "@fusion/core";
 
 function makeCtx(cwd: string) {
   return { cwd } as any;
 }
 
+async function loadExtension() {
+  const mod = await import("../extension.js");
+  return mod.default;
+}
+
 describe("extension task tools resolve repo root from worktrees", () => {
+  beforeEach(() => {
+    vi.resetModules();
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+    vi.unmock("@fusion/core");
+  });
+
+  it("exports getProjectRootFromWorktree from @fusion/core", () => {
+    expect(typeof getProjectRootFromWorktree).toBe("function");
+  });
+
   it("uses canonical project root for fn_task_show and fn_task_list from worktree cwd", async () => {
     const repoRoot = await mkdtemp(join(tmpdir(), "fn-4904-cli-"));
     const worktreeRoot = join(repoRoot, ".worktrees", "feature");
     try {
       await mkdir(join(repoRoot, ".fusion"), { recursive: true });
-      await mkdir(join(worktreeRoot, ".fusion"), { recursive: true });
 
       const store = new TaskStore(repoRoot);
       await store.init();
-      await store.createTask({ description: "Task from canonical root" });
+      const created = await store.createTask({ description: "Task from canonical root" });
 
+      const extension = await loadExtension();
       const tools = new Map<string, any>();
-      kbExtension({
+      extension({
         registerTool(def: any) {
           tools.set(def.name, def);
         },
@@ -37,12 +54,62 @@ describe("extension task tools resolve repo root from worktrees", () => {
       expect(showTool).toBeTruthy();
       expect(listTool).toBeTruthy();
 
-      const show = await showTool.execute("show", { id: "FN-001" }, undefined, undefined, makeCtx(worktreeRoot));
+      const show = await showTool.execute("show", { id: created.id }, undefined, undefined, makeCtx(worktreeRoot));
       const list = await listTool.execute("list", {}, undefined, undefined, makeCtx(worktreeRoot));
 
-      expect(show.content[0].text).toContain("FN-001");
+      expect(Array.isArray(list.content)).toBe(true);
+      expect(typeof list.details?.count).toBe("number");
+
+      expect(show.content[0].text).toContain(created.id);
       expect(show.content[0].text).toContain("Task from canonical root");
-      expect(list.content[0].text).toContain("FN-001");
+      expect(list.content[0].text).toContain(created.id);
+    } finally {
+      await rm(repoRoot, { recursive: true, force: true });
+    }
+  });
+
+  it("falls back when getProjectRootFromWorktree is unavailable in no-task context", async () => {
+    const repoRoot = await mkdtemp(join(tmpdir(), "fn-4927-cli-"));
+    const worktreeRoot = join(repoRoot, ".worktrees", "ambient");
+    try {
+      await mkdir(join(repoRoot, ".fusion"), { recursive: true });
+
+      const store = new TaskStore(repoRoot);
+      await store.init();
+      const created = await store.createTask({ description: "Ambient tool check" });
+
+      const warnSpy = vi.spyOn(console, "warn").mockImplementation(() => {});
+      vi.doMock("@fusion/core", async () => {
+        const actual = await vi.importActual<typeof import("@fusion/core")>("@fusion/core");
+        return {
+          ...actual,
+          getProjectRootFromWorktree: undefined,
+        };
+      });
+
+      const extension = await loadExtension();
+      const tools = new Map<string, any>();
+      extension({
+        registerTool(def: any) {
+          tools.set(def.name, def);
+        },
+        registerCommand: vi.fn(),
+        registerShortcut: vi.fn(),
+        registerFlag: vi.fn(),
+        on: vi.fn(),
+      } as any);
+
+      const listTool = tools.get("fn_task_list");
+      const showTool = tools.get("fn_task_show");
+
+      const list = await listTool.execute("list", {}, undefined, undefined, makeCtx(worktreeRoot));
+      const show = await showTool.execute("show", { id: created.id }, undefined, undefined, makeCtx(worktreeRoot));
+
+      expect(Array.isArray(list.content)).toBe(true);
+      expect(typeof list.details?.count).toBe("number");
+      expect(Array.isArray(show.content)).toBe(true);
+      expect(show.content[0]?.text).toContain(created.id);
+      expect(warnSpy).toHaveBeenCalledTimes(1);
     } finally {
       await rm(repoRoot, { recursive: true, force: true });
     }