test(FN-4946): add implicit completion refusal guard coverage

Fusion-Task-Id: FN-4946
Fusion-Task-Lineage: 9a48f72f-d2cc-4950-8a00-f69053dd1163

packages/engine/src/__tests__/executor-implicit-task-done-budget.test.ts

@@ -0,0 +1,61 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import "./executor-test-helpers.js";
+import { TaskExecutor } from "../executor.js";
+import { executorLog } from "../logger.js";
+import { createMockStore, resetExecutorMocks } from "./executor-test-helpers.js";
+
+function refusal() {
+  return {
+    ok: false as const,
+    refusalClass: "pending-code-review-revise" as const,
+    reason: "Step 1 has pending REVISE",
+    message: "fn_task_done refused (pending-code-review-revise): Step 1 has pending REVISE",
+  };
+}
+
+function task(retryCount: number) {
+  return {
+    id: "FN-4946-B",
+    title: "Budget",
+    description: "",
+    column: "in-progress",
+    worktree: "/repo/.worktrees/swift-falcon",
+    branch: "fusion/fn-4946-b",
+    baseCommitSha: "abc123",
+    taskDoneRetryCount: retryCount,
+    dependencies: [],
+    steps: [{ name: "Step 1", status: "in-progress" as const }],
+    currentStep: 0,
+    createdAt: new Date().toISOString(),
+    updatedAt: new Date().toISOString(),
+  } as any;
+}
+
+describe("FN-4946 implicit refusal budget handling", () => {
+  beforeEach(() => {
+    resetExecutorMocks();
+  });
+
+  it("requeues to todo under budget", async () => {
+    const store = createMockStore();
+    const executor = new TaskExecutor(store as any, "/repo");
+
+    await (executor as any).handleImplicitTaskDoneRefusal(task(2), "/repo/.worktrees/swift-falcon", refusal());
+
+    expect(store.updateTask).toHaveBeenCalledWith("FN-4946-B", expect.objectContaining({ taskDoneRetryCount: 3, status: "failed" }));
+    expect(store.moveTask).toHaveBeenCalledWith("FN-4946-B", "todo", { preserveProgress: true });
+    expect(executorLog.error).toHaveBeenCalledWith(expect.stringContaining("(implicit completion)"));
+  });
+
+  it("escalates to in-review at budget limit", async () => {
+    const store = createMockStore();
+    const executor = new TaskExecutor(store as any, "/repo");
+    const persistSpy = vi.spyOn(executor as any, "persistTokenUsage").mockResolvedValue(undefined);
+
+    await (executor as any).handleImplicitTaskDoneRefusal(task(3), "/repo/.worktrees/swift-falcon", refusal());
+
+    expect(store.updateTask).toHaveBeenCalledWith("FN-4946-B", expect.objectContaining({ status: "failed" }));
+    expect(store.moveTask).toHaveBeenCalledWith("FN-4946-B", "in-review");
+    expect(persistSpy).toHaveBeenCalledWith("FN-4946-B");
+  });
+});

packages/engine/src/__tests__/executor-implicit-task-done-revise-guard.test.ts

@@ -0,0 +1,72 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import "./executor-test-helpers.js";
+import { TaskExecutor } from "../executor.js";
+import { reviewStep } from "../reviewer.js";
+import { createMockStore, mockedCreateFnAgent, mockedExecSync, resetExecutorMocks } from "./executor-test-helpers.js";
+
+function makeTask(overrides: Record<string, unknown> = {}) {
+  return {
+    id: "FN-4946-R",
+    title: "Implicit revise guard",
+    description: "",
+    column: "in-progress",
+    worktree: "/repo/.worktrees/swift-falcon",
+    branch: "fusion/fn-4946-r",
+    baseCommitSha: "abc123",
+    taskDoneRetryCount: 0,
+    dependencies: [],
+    steps: [{ name: "Step 1", status: "in-progress" as const }],
+    currentStep: 0,
+    createdAt: new Date().toISOString(),
+    updatedAt: new Date().toISOString(),
+    ...overrides,
+  };
+}
+
+describe("FN-4946 implicit completion + REVISE verdict interaction", () => {
+  beforeEach(() => {
+    resetExecutorMocks();
+    mockedExecSync.mockImplementation((cmd: string) => {
+      if (cmd.includes("rev-parse --show-toplevel")) return Buffer.from("/repo/.worktrees/swift-falcon\n");
+      if (cmd.includes("rev-parse --abbrev-ref HEAD")) return Buffer.from("fusion/fn-4946-r\n");
+      if (cmd.includes("rev-list --count")) return Buffer.from("1\n");
+      if (cmd.includes("rev-parse HEAD")) return Buffer.from("def456\n");
+      return Buffer.from("");
+    });
+  });
+
+  it("does not refuse implicit completion when REVISE is on an already done step", async () => {
+    const store = createMockStore();
+    let task: any = makeTask();
+
+    store.getTask.mockImplementation(async () => ({ ...task, steps: task.steps.map((s: any) => ({ ...s })) }));
+    store.updateStep.mockImplementation(async (_id: string, step: number, patch: any) => {
+      task.steps[step] = { ...task.steps[step], ...patch };
+    });
+
+    vi.mocked(reviewStep).mockResolvedValue({ verdict: "REVISE", summary: "fix", review: "fix" } as any);
+
+    mockedCreateFnAgent.mockImplementation(async ({ customTools }: any) => {
+      const updateTool = customTools.find((t: any) => t.name === "fn_task_update");
+      const reviewTool = customTools.find((t: any) => t.name === "fn_review_step");
+      return {
+        session: {
+          prompt: vi.fn().mockImplementation(async () => {
+            await reviewTool.execute("review", { step: 0, type: "code", step_name: "Step 1", baseline: "abc123" });
+            await updateTool.execute("update", { step: 0, status: "done" });
+          }),
+          dispose: vi.fn(),
+          subscribe: vi.fn(),
+          on: vi.fn(),
+          state: {},
+        },
+      } as any;
+    });
+
+    const executor = new TaskExecutor(store as any, "/repo");
+    await executor.execute(task);
+
+    expect(store.moveTask).toHaveBeenCalledWith("FN-4946-R", "in-review");
+    expect(store.moveTask).not.toHaveBeenCalledWith("FN-4946-R", "todo", { preserveProgress: true });
+  });
+});

packages/engine/src/__tests__/executor-task-done-shared-helper.test.ts

@@ -0,0 +1,38 @@
+import { describe, expect, it } from "vitest";
+import { readFileSync } from "node:fs";
+import { evaluateTaskDoneRefusal } from "../executor.js";
+
+describe("FN-4946 shared task_done refusal helper invariant", () => {
+  it("keeps a single helper implementation and routes explicit+implicit paths through it", () => {
+    const source = readFileSync(new URL("../executor.ts", import.meta.url), "utf8");
+    const invocations = source.match(/evaluateTaskDoneRefusal\(/g) ?? [];
+    const helperDecl = source.match(/\bfunction evaluateTaskDoneRefusal\b/g) ?? [];
+    const dissentDecl = source.match(/\bconst DISSENT_PATTERNS\b/g) ?? [];
+
+    expect(invocations.length).toBeGreaterThanOrEqual(3);
+    expect(helperDecl).toHaveLength(1);
+    expect(dissentDecl).toHaveLength(1);
+  });
+
+  it("returns pending-code-review-revise for a pending step with REVISE and no summary", () => {
+    const result = evaluateTaskDoneRefusal(
+      {
+        id: "FN-4946-H",
+        title: "t",
+        description: "",
+        column: "in-progress",
+        dependencies: [],
+        steps: [{ name: "Step 1", status: "in-progress" }],
+        currentStep: 0,
+        createdAt: new Date().toISOString(),
+        updatedAt: new Date().toISOString(),
+      } as any,
+      {},
+      new Map([[0, "REVISE"]]),
+    );
+
+    expect(result.ok).toBe(false);
+    if (result.ok) throw new Error("expected refusal");
+    expect(result.refusalClass).toBe("pending-code-review-revise");
+  });
+});