fusion/packages/engine/src/__tests__/executor-workspace.test.ts

/*
FNXC:Workspace 2026-06-21-12:00:
U1 executor session-scoping tests. REWRITTEN from the foundation's self-mocking version (which vi.mock'd the very functions under test and proved nothing). These tests use a REAL two-repo git fixture (`createWorkspaceFixture`) under a NON-git workspace root, so a leaked rootDir git preflight would actually fail. They drive the real TaskExecutor methods that U1 changed: the activeWorktrees Set conversion + every enumerated consumer (KTD2), the preflight gate + browse-only-root scoping (KTD1), and the synthetic-acquisition cwd.

Seam choice (FN-5048): `(executor as any).workspaceConfig` is set directly to drive the gating with real git — loadWorkspaceConfig is covered by its own unit and is not the subject here. No mock-the-world child_process/fs shell.
*/
import { afterEach, describe, expect, it, vi } from "vitest";
import { EventEmitter } from "node:events";
import { loadWorkspaceConfig, type Task, type TaskStore, type WorkspaceConfig } from "@fusion/core";
import { TaskExecutor, buildExecutionPrompt } from "../executor.js";
import { activeSessionRegistry } from "../active-session-registry.js";
import { createWorkspaceFixture, hasGit, type WorkspaceFixture } from "./_workspace-fixture.js";

const describeIfGit = hasGit ? describe : describe.skip;

function createStore(overrides: Partial<Record<string, unknown>> = {}): TaskStore & EventEmitter {
  const emitter = new EventEmitter();
  return Object.assign(emitter, {
    updateTask: vi.fn().mockResolvedValue(undefined),
    logEntry: vi.fn().mockResolvedValue(undefined),
    getSettings: vi.fn().mockResolvedValue({ autoMerge: false }),
    on: emitter.on.bind(emitter),
    ...overrides,
  }) as unknown as TaskStore & EventEmitter;
}

function makeTask(id = "FN-WS-1", overrides: Partial<Task> = {}): Task {
  return {
    id,
    title: "Workspace task",
    description: "",
    column: "in-progress",
    dependencies: [],
    steps: [],
    currentStep: 0,
    log: [],
    createdAt: new Date().toISOString(),
    updatedAt: new Date().toISOString(),
    ...overrides,
  } as Task;
}

const repoAPath = (fx: WorkspaceFixture) => `${fx.repoPath("repo-a")}/.worktrees/fn-ws-1`;
const repoBPath = (fx: WorkspaceFixture) => `${fx.repoPath("repo-b")}/.worktrees/fn-ws-1`;

describeIfGit("workspace fixture", () => {
  let fx: WorkspaceFixture;
  afterEach(() => fx?.cleanup());

  it("builds a non-git root with two real git sub-repos and a resolvable workspace config", async () => {
    fx = await createWorkspaceFixture();
    // Root is NOT a git repo. Use "." so the check runs in fx.rootDir itself, not
    // its parent (".." would resolve to the tmpdir and could pass spuriously).
    expect(() => fx.git(".", "git rev-parse --git-dir")).toThrow();
    // Each sub-repo is a real git repo with a commit on main.
    expect(fx.git("repo-a", "git rev-parse --abbrev-ref HEAD")).toBe("main");
    expect(fx.git("repo-b", "git rev-list --count HEAD")).toBe("1");
    // loadWorkspaceConfig resolves the on-disk config the executor keys off.
    const config = await loadWorkspaceConfig(fx.rootDir);
    expect(config?.repos).toEqual(["repo-a", "repo-b"]);
  });
});

describeIfGit("U1 KTD2 — activeWorktrees Set + every enumerated consumer", () => {
  let fx: WorkspaceFixture;
  /*
  FNXC:TestInfrastructure 2026-07-29-22:05 (#2617 review — greptile P2):
  `activeSessionRegistry` is PROCESS-GLOBAL and is itself a liveness signal
  (hasLiveSessionSurface reads it), so a registration leaked by a failing assertion
  makes the NEXT test see a phantom live session and refuse a clear it should permit.
  Unregistering after the assertions only works on the happy path. Sweep in
  guaranteed teardown instead — this suite is precisely the one that measures that
  registry, so it must not be the one polluting it.
  */
  afterEach(() => {
    for (const path of activeSessionRegistry.pathsForTask("FN-WS-1")) {
      activeSessionRegistry.unregisterPath(path);
    }
  });
  afterEach(() => fx?.cleanup());

  function workspaceExecutor() {
    fx ??= undefined as never;
    const store = createStore();
    const executor = new TaskExecutor(store, fx.rootDir);
    (executor as any).workspaceConfig = { repos: fx.repos } as WorkspaceConfig;
    return executor;
  }

  it("a workspace task holding TWO sub-repo paths is found by membership, not equality", async () => {
    fx = await createWorkspaceFixture();
    const executor = workspaceExecutor();
    const pA = repoAPath(fx);
    const pB = repoBPath(fx);
    (executor as any).addActiveWorktree("FN-WS-1", pA);
    (executor as any).addActiveWorktree("FN-WS-1", pB);

    // hasActiveWorktreeBinding: both held paths match; an unheld path does not.
    expect((executor as any).hasActiveWorktreeBinding("FN-WS-1", pA)).toBe(true);
    expect((executor as any).hasActiveWorktreeBinding("FN-WS-1", pB)).toBe(true);
    expect((executor as any).hasActiveWorktreeBinding("FN-WS-1", "/nope")).toBe(false);

    // findActiveWorktreeOwner: another task asking about either held path finds FN-WS-1.
    await expect((executor as any).findActiveWorktreeOwner(pA, "FN-OTHER")).resolves.toBe("FN-WS-1");
    await expect((executor as any).findActiveWorktreeOwner(pB, "FN-OTHER")).resolves.toBe("FN-WS-1");
    // The owner itself is excluded.
    await expect((executor as any).findActiveWorktreeOwner(pA, "FN-WS-1")).resolves.toBeNull();
  });

  it("listWorktreeHolders flat-maps the Set into N holder rows for one task", async () => {
    fx = await createWorkspaceFixture();
    const executor = workspaceExecutor();
    const pA = repoAPath(fx);
    const pB = repoBPath(fx);
    (executor as any).addActiveWorktree("FN-WS-1", pA);
    (executor as any).addActiveWorktree("FN-WS-1", pB);

    const holders = executor.listWorktreeHolders();
    expect(holders).toHaveLength(2);
    expect(holders).toContainEqual({ taskId: "FN-WS-1", worktreePath: pA });
    expect(holders).toContainEqual({ taskId: "FN-WS-1", worktreePath: pB });
  });

  it("shouldGenerateNewWorktreeName iterates the Set (conflict membership)", async () => {
    fx = await createWorkspaceFixture();
    const store = createStore({ listTasks: vi.fn().mockResolvedValue([]) });
    const executor = new TaskExecutor(store, fx.rootDir);
    (executor as any).workspaceConfig = { repos: fx.repos } as WorkspaceConfig;
    const pA = repoAPath(fx);
    (executor as any).addActiveWorktree("FN-HOLDER", pA);

    // A different task contending for FN-HOLDER's path must be told to generate a new name.
    await expect((executor as any).shouldGenerateNewWorktreeName(pA, "FN-WS-1")).resolves.toBe(true);
    // The holder asking about its own path is not a conflict (excluded), and the
    // DB liveness fallback returns no other user.
    await expect((executor as any).shouldGenerateNewWorktreeName(pA, "FN-HOLDER")).resolves.toBe(false);
  });

  it("getWorktreePath returns undefined for a multi-worktree workspace task (Set-collapse contract)", async () => {
    fx = await createWorkspaceFixture();
    const executor = workspaceExecutor();
    (executor as any).addActiveWorktree("FN-WS-1", repoAPath(fx));
    (executor as any).addActiveWorktree("FN-WS-1", repoBPath(fx));
    expect(executor.getWorktreePath("FN-WS-1")).toBeUndefined();
  });

  it("cleanup drops in-memory tracking in workspace mode but never removes the root", async () => {
    fx = await createWorkspaceFixture();
    const removeSpy = vi.fn();
    const executor = workspaceExecutor();
    (executor as any).removeOwnWorktreeWithReconcile = removeSpy;
    (executor as any).addActiveWorktree("FN-WS-1", repoAPath(fx));
    (executor as any).addActiveWorktree("FN-WS-1", repoBPath(fx));

    await executor.cleanup("FN-WS-1");

    expect(executor.getWorktreePath("FN-WS-1")).toBeUndefined();
    expect((executor as any).activeWorktrees.has("FN-WS-1")).toBe(false);
    // The browse-only root must never be torn down as if it were a worktree.
    expect(removeSpy).not.toHaveBeenCalled();
  });

  /*
  FNXC:NodeWorktreeIsolation 2026-07-29-18:20 (U9 re-green; consequence of PR #2531):
  These two cases used to assert that `clearPhantomExecutorBinding` SUCCEEDS while
  session-registry paths are held, and swept (or preserved) them. FN-6756 inverted
  that: `hasLiveSessionSurface` now includes
  `activeSessionRegistry.pathsForTask(taskId).length > 0`, and that guard runs
  BEFORE both branches — so any registered path refuses the clear outright. The old
  expectations describe the pre-#2531 contract.

  Rewritten to assert the CURRENT contract, which is the P0 fix's actual promise and
  had no direct coverage: a registered surface of any kind means someone is working
  in that worktree, so the reclaim refuses rather than reaping it.

  ⚠️ FLAG FOR THE #2531 OWNER — not fixed here, because it is a product decision:
  the guard appears to make BOTH of the branches it precedes unreachable for their
  stated purpose.
    - the default branch exists to unregister every held registry path (FN-6736);
    - `preserveWorktrees: true` exists to KEEP those registry paths so a
      `moveTask(preserveWorktree:true)` re-dispatch reattaches to the same worktree
      (FN-7249), and its ONLY production caller is the self-healing reclaim at
      self-healing.ts:3565.
  Both require registered paths to do anything, and the guard rejects exactly that
  case. With no registered paths, one sweeps nothing and the other preserves
  nothing. The third case below pins this so the conflict is executable rather than
  prose. Resolving it — e.g. exempting the non-destructive `preserveWorktrees` path,
  or narrowing the guard by kind — belongs to whoever owns FN-6756.
  */
  it("clearPhantomExecutorBinding refuses while a session-registry path is held (FN-6756)", async () => {
    fx = await createWorkspaceFixture();
    const executor = workspaceExecutor();
    const pA = repoAPath(fx);
    const pB = repoBPath(fx);
    (executor as any).addActiveWorktree("FN-WS-1", pA);
    (executor as any).addActiveWorktree("FN-WS-1", pB);
    activeSessionRegistry.registerPath(pA, { taskId: "FN-WS-1", kind: "executor", ownerKey: "exec:FN-WS-1:a" });
    activeSessionRegistry.registerPath(pB, { taskId: "FN-WS-1", kind: "executor", ownerKey: "exec:FN-WS-1:b" });

    expect((executor as any).clearPhantomExecutorBinding("FN-WS-1")).toBe(false);
    // Nothing may be torn down on a refusal — that is the whole point of the guard.
    expect((executor as any).activeWorktrees.has("FN-WS-1")).toBe(true);
    expect(activeSessionRegistry.pathsForTask("FN-WS-1")).toEqual(expect.arrayContaining([pA, pB]));
    // Cleanup is in afterEach, so a failure above cannot leak these registrations.
  });

  it("clearPhantomExecutorBinding (FN-6736) clears every held path once no session surface remains", async () => {
    fx = await createWorkspaceFixture();
    const executor = workspaceExecutor();
    const pA = repoAPath(fx);
    const pB = repoBPath(fx);
    (executor as any).addActiveWorktree("FN-WS-1", pA);
    (executor as any).addActiveWorktree("FN-WS-1", pB);

    // No registry paths held, so the guard permits the clear. KTD2: a workspace task
    // holds N worktrees and ALL of them must leave the binding, not just the first.
    expect((executor as any).clearPhantomExecutorBinding("FN-WS-1")).toBe(true);
    expect((executor as any).activeWorktrees.has("FN-WS-1")).toBe(false);
    expect((executor as any).executing.has("FN-WS-1")).toBe(false);
    expect(activeSessionRegistry.pathsForTask("FN-WS-1")).toEqual([]);
  });

  it("FN-7249 preserveWorktrees cannot run while the paths it exists to preserve are registered", async () => {
    fx = await createWorkspaceFixture();
    const executor = workspaceExecutor();
    const pA = repoAPath(fx);
    (executor as any).addActiveWorktree("FN-WS-1", pA);
    activeSessionRegistry.registerPath(pA, { taskId: "FN-WS-1", kind: "executor", ownerKey: "exec:FN-WS-1:a" });

    // The guard precedes the preserveWorktrees branch, so the one scenario that
    // branch was written for is the one it can never reach.
    expect((executor as any).clearPhantomExecutorBinding("FN-WS-1", { preserveWorktrees: true })).toBe(false);
    expect((executor as any).activeWorktrees.has("FN-WS-1")).toBe(true);
  });
});

describeIfGit("U1 KTD2 — non-workspace task is a one-element Set (regression: unchanged)", () => {
  let fx: WorkspaceFixture;
  afterEach(() => fx?.cleanup());

  it("getWorktreePath returns the sole path; listWorktreeHolders emits exactly one row", async () => {
    fx = await createWorkspaceFixture();
    const store = createStore();
    const executor = new TaskExecutor(store, fx.repoPath("repo-a")); // single-repo root
    // No workspaceConfig set → single-repo mode.
    const wt = `${fx.repoPath("repo-a")}/.worktrees/fn-001`;
    (executor as any).addActiveWorktree("FN-001", wt);

    expect(executor.getWorktreePath("FN-001")).toBe(wt);
    expect(executor.listWorktreeHolders()).toEqual([{ taskId: "FN-001", worktreePath: wt }]);
    expect((executor as any).hasActiveWorktreeBinding("FN-001", wt)).toBe(true);
  });
});

describeIfGit("U1 KTD1 — verifyWorktreeInvariants gated off in workspace mode", () => {
  let fx: WorkspaceFixture;
  afterEach(() => fx?.cleanup());

  it("returns ok for a zero-acquire workspace task (no task.worktree) so fn_task_done does not requeue", async () => {
    fx = await createWorkspaceFixture();
    const store = createStore();
    const executor = new TaskExecutor(store, fx.rootDir);
    (executor as any).workspaceConfig = { repos: fx.repos } as WorkspaceConfig;

    // A workspace task that acquired ZERO sub-repos has no task.worktree and no
    // tracked paths. The singular invariant would otherwise refuse on
    // "missing task.worktree"; in workspace mode it is gated OFF.
    const result = await (executor as any).verifyWorktreeInvariants(makeTask("FN-WS-1", { worktree: undefined }));
    expect(result).toEqual({ ok: true });
  });

  it("non-workspace task with no worktree still fails the invariant (regression: gate is workspace-only)", async () => {
    fx = await createWorkspaceFixture();
    const store = createStore();
    const executor = new TaskExecutor(store, fx.repoPath("repo-a"));
    // No workspaceConfig.
    const result = await (executor as any).verifyWorktreeInvariants(makeTask("FN-001", { worktree: undefined }));
    expect(result.ok).toBe(false);
  });
});

describeIfGit("U1 KTD1 — scopePromptToWorktree / buildExecutionPrompt no-op in workspace mode", () => {
  let fx: WorkspaceFixture;
  afterEach(() => fx?.cleanup());

  it("does not rewrite root-anchored paths when a workspace config is present", async () => {
    fx = await createWorkspaceFixture();
    const task = makeTask("FN-WS-1", { prompt: `Edit ${fx.rootDir}/repo-a/src/index.ts and commit.` });
    const config: WorkspaceConfig = { repos: fx.repos };
    // worktreePath === rootDir in workspace mode; the prompt must be returned verbatim.
    const prompt = buildExecutionPrompt(task as any, fx.rootDir, { autoMerge: false } as any, fx.rootDir, undefined, undefined, config);
    expect(prompt).toContain(`${fx.rootDir}/repo-a/src/index.ts`);
    // The workspace repo list is appended (foundation behavior).
    expect(prompt).toContain("repo-a");
  });
});