fix: detach all memory tools when enabling memfs (#900)

Co-authored-by: Letta <noreply@letta.com>

src/tests/tools/toolset-memfs-detach.test.ts

@@ -0,0 +1,75 @@
+// Tests for detaching server-side memory tools when enabling memfs
+
+import { beforeEach, describe, expect, mock, test } from "bun:test";
+
+// Mock getClient before importing the module under test
+
+const detachMock = mock((_toolId: string, _opts: { agent_id: string }) =>
+  Promise.resolve({}),
+);
+const retrieveMock = mock((_agentId: string, _opts?: Record<string, unknown>) =>
+  Promise.resolve({
+    tools: [
+      { name: "memory", id: "tool-memory" },
+      { name: "memory_apply_patch", id: "tool-memory-apply" },
+      { name: "memory_insert", id: "tool-memory-insert" },
+      { name: "memory_replace", id: "tool-memory-replace" },
+      { name: "memory_rethink", id: "tool-memory-rethink" },
+      { name: "web_search", id: "tool-web-search" },
+      // No id should be ignored
+      { name: "memory_replace" },
+    ],
+  }),
+);
+
+const mockGetClient = mock(() =>
+  Promise.resolve({
+    agents: {
+      retrieve: retrieveMock,
+      tools: {
+        detach: detachMock,
+      },
+    },
+  }),
+);
+
+mock.module("../../agent/client", () => ({
+  getClient: mockGetClient,
+}));
+
+const { detachMemoryTools } = await import("../../tools/toolset");
+
+describe("detachMemoryTools", () => {
+  beforeEach(() => {
+    detachMock.mockClear();
+    retrieveMock.mockClear();
+    mockGetClient.mockClear();
+  });
+
+  test("detaches all known memory tool variants", async () => {
+    const detached = await detachMemoryTools("agent-123");
+    expect(detached).toBe(true);
+
+    const detachedToolIds = detachMock.mock.calls.map((call) => call[0]);
+    expect(detachedToolIds).toEqual([
+      "tool-memory",
+      "tool-memory-apply",
+      "tool-memory-insert",
+      "tool-memory-replace",
+      "tool-memory-rethink",
+    ]);
+
+    // Ensure we did not detach unrelated tools
+    expect(detachedToolIds.includes("tool-web-search")).toBe(false);
+  });
+
+  test("returns false when no memory tools are attached", async () => {
+    retrieveMock.mockResolvedValueOnce({
+      tools: [{ name: "web_search", id: "tool-web-search" }],
+    });
+
+    const detached = await detachMemoryTools("agent-123");
+    expect(detached).toBe(false);
+    expect(detachMock).not.toHaveBeenCalled();
+  });
+});