test(FN-4429): complete Step 4 — add executor user-cancel regression coverage

Fusion-Task-Id: FN-4429
Fusion-Task-Lineage: b010437b-0e58-43f6-81b3-40dcebbf0873

packages/engine/src/__tests__/executor-user-cancel.test.ts

@@ -0,0 +1,96 @@
+import { describe, it, expect, vi } from "vitest";
+import "./executor-test-helpers.js";
+import { TaskExecutor } from "../executor.js";
+import { createMockStore, resetExecutorMocks } from "./executor-test-helpers.js";
+
+describe("TaskExecutor user cancel handling", () => {
+  it("aborts before dispose when user moves in-progress task back to todo", async () => {
+    resetExecutorMocks();
+    const store = createMockStore();
+    const executor = new TaskExecutor(store as any, "/tmp/test");
+
+    const callOrder: string[] = [];
+    const session = {
+      prompt: vi.fn(),
+      abort: vi.fn(async () => {
+        callOrder.push("abort");
+      }),
+      dispose: vi.fn(() => {
+        callOrder.push("dispose");
+      }),
+    } as any;
+
+    (executor as any).activeSessions.set("FN-001", {
+      session,
+      seenSteeringIds: new Set<string>(),
+    });
+
+    (store as any)._trigger("task:moved", {
+      task: {
+        id: "FN-001",
+        column: "todo",
+        dependencies: [],
+        steps: [],
+        currentStep: 0,
+        log: [],
+      },
+      from: "in-progress",
+      to: "todo",
+      source: "user",
+    });
+
+    await Promise.resolve();
+
+    expect(callOrder[0]).toBe("abort");
+    expect(callOrder[1]).toBe("dispose");
+    expect((executor as any).activeSessions.has("FN-001")).toBe(false);
+    expect((executor as any).userCanceledTaskIds.has("FN-001")).toBe(true);
+    expect(store.moveTask).not.toHaveBeenCalled();
+  });
+
+  it("does not mark engine-initiated move as user cancel", () => {
+    resetExecutorMocks();
+    const store = createMockStore();
+    const executor = new TaskExecutor(store as any, "/tmp/test");
+
+    (store as any)._trigger("task:moved", {
+      task: {
+        id: "FN-002",
+        column: "todo",
+        dependencies: [],
+        steps: [],
+        currentStep: 0,
+        log: [],
+      },
+      from: "in-progress",
+      to: "todo",
+      source: "engine",
+    });
+
+    expect((executor as any).userCanceledTaskIds.has("FN-002")).toBe(false);
+  });
+
+  it("clears userCanceled marker when task is moved back to in-progress", () => {
+    resetExecutorMocks();
+    const store = createMockStore();
+    const executor = new TaskExecutor(store as any, "/tmp/test");
+
+    (executor as any).userCanceledTaskIds.add("FN-003");
+
+    (store as any)._trigger("task:moved", {
+      task: {
+        id: "FN-003",
+        column: "in-progress",
+        dependencies: [],
+        steps: [],
+        currentStep: 0,
+        log: [],
+      },
+      from: "todo",
+      to: "in-progress",
+      source: "user",
+    });
+
+    expect((executor as any).userCanceledTaskIds.has("FN-003")).toBe(false);
+  });
+});