test(apple-runner): one device-set redirect double for the session tests

The size ratchet refused this PR's six-line growth in `runner-session.test.ts`, which is 1,955 lines at
the merge-base and already over the tripwire, and its own remedy is the right one here: the handle the
launch hands the session was being fabricated four times over, twice in that file alone, with a
per-file spy that each file then counted calls on. It now lives once in `runner-session-fixtures.ts`,
the module this test family already shares, and the family is five lines shorter than it was.

One spy answers both give-backs on purpose. The session-level tests ask whether the host's device set
came back when a launch failed or a session was disposed; which of the two doors it came back through
is the thing this PR changed, and that is pinned where the handle is made, in
`runner-device-set.test.ts`, where each door is a separate test.

Author: thymikee

packages/platform-apple/src/runner/__tests__/runner-request-cancellation.test.ts

@@ -5,6 +5,7 @@ import path from 'node:path';
 import { beforeEach, test, vi } from 'vitest';
 import { IOS_DEVICE, IOS_SIMULATOR } from './device-fixtures.ts';
 import { mkdtempForTestSync } from './tmp-dir.ts';
+import { redirectHandle } from './runner-session-fixtures.ts';
 import { appleRunnerTestHost } from '../test-host.ts';
 
 const {
@@ -22,7 +23,6 @@ const {
   mockSignalPidsBestEffort,
   mockSignalProcessGroupBestEffort,
   mockWaitForRunner,
-  mockRedirectRelease,
 } = vi.hoisted(() => ({
   mockAcquireXcodebuildSimulatorSetRedirect: vi.fn(),
   mockEnsureXctestrunArtifact: vi.fn(),
@@ -39,7 +39,6 @@ const {
   mockSignalPidsBestEffort: vi.fn(),
   mockSignalProcessGroupBestEffort: vi.fn(),
   mockWaitForRunner: vi.fn(),
-  mockRedirectRelease: vi.fn(),
 }));
 
 vi.mock('../runner-io.ts', async () => {
@@ -155,10 +154,7 @@ beforeEach(async () => {
   });
   mockResolveExpectedRunnerCacheMetadata.mockReturnValue({ schemaVersion: 1 });
   mockResolveRunnerDerivedPath.mockReturnValue('/tmp/derived');
-  mockAcquireXcodebuildSimulatorSetRedirect.mockResolvedValue({
-    release: mockRedirectRelease,
-    releaseBestEffort: mockRedirectRelease,
-  });
+  mockAcquireXcodebuildSimulatorSetRedirect.mockResolvedValue(redirectHandle);
   mockRunCmdBackground.mockReturnValue(makeBackgroundRunner(4242));
   mockRunAppleToolCommand.mockResolvedValue({ exitCode: 0, stdout: '', stderr: '' });
   mockIsProcessAlive.mockReturnValue(true);

packages/platform-apple/src/runner/__tests__/runner-session-fixtures.ts

@@ -1,10 +1,12 @@
 import assert from 'node:assert/strict';
 import fs from 'node:fs';
 import { EventEmitter } from 'node:events';
+import { vi } from 'vitest';
 import { IOS_SIMULATOR } from './device-fixtures.ts';
 import { appleRunnerTestHost } from '../test-host.ts';
 import { runnerOwnerStartTime, type RunnerLease } from '../runner-lease.ts';
 import type { RunnerSession } from '../runner-session-types.ts';
+import type { XcodebuildSimulatorSetRedirectHandle } from '../runner-device-set.ts';
 
 // Fabricated runner sessions, leases, background children, and transport
 // payloads shared by the runner-session tests. The child pids here are made up
@@ -182,3 +184,14 @@ export function makeClassifyOwnerLivenessViaMocks(deps: {
     return stateDir ? classifyStateDir(stateDir) : 'live';
   };
 }
+
+/**
+ * The give-back a launched session holds. One spy answers both strictnesses: the the host's device set came back, and which door it came back
+ * through is pinned where the handle is made, in `runner-device-set.test.ts`.
+ */
+export const redirectRelease = vi.fn(async () => {});
+
+export const redirectHandle: XcodebuildSimulatorSetRedirectHandle = {
+  release: redirectRelease,
+  releaseBestEffort: redirectRelease,
+};

packages/platform-apple/src/runner/__tests__/runner-session-speculative.test.ts

@@ -6,6 +6,7 @@ import {
   makeBackgroundRunner,
   makeClassifyOwnerLivenessViaMocks,
   runnerResponse,
+  redirectHandle,
 } from './runner-session-fixtures.ts';
 import { mkdtempForTestSync } from './tmp-dir.ts';
 
@@ -28,7 +29,6 @@ const {
   mockSignalPidsBestEffort,
   mockSignalProcessGroupBestEffort,
   mockWaitForRunner,
-  mockRedirectRelease,
 } = vi.hoisted(() => ({
   mockAcquireXcodebuildSimulatorSetRedirect: vi.fn(),
   mockCleanupTempFile: vi.fn(),
@@ -52,7 +52,6 @@ const {
   mockSignalPidsBestEffort: vi.fn(),
   mockSignalProcessGroupBestEffort: vi.fn(),
   mockWaitForRunner: vi.fn(),
-  mockRedirectRelease: vi.fn(),
 }));
 
 vi.mock('../runner-io.ts', async () => {
@@ -138,10 +137,7 @@ beforeEach(async () => {
   });
   mockResolveExpectedRunnerCacheMetadata.mockReturnValue({ schemaVersion: 1 });
   mockResolveRunnerDerivedPath.mockReturnValue('/tmp/derived');
-  mockAcquireXcodebuildSimulatorSetRedirect.mockResolvedValue({
-    release: mockRedirectRelease,
-    releaseBestEffort: mockRedirectRelease,
-  });
+  mockAcquireXcodebuildSimulatorSetRedirect.mockResolvedValue(redirectHandle);
   mockRunCmdBackground.mockReturnValue(makeBackgroundRunner(4242));
   mockRunAppleToolCommand.mockResolvedValue({ exitCode: 0, stdout: '', stderr: '' });
   mockIsProcessAlive.mockReturnValue(true);
@@ -192,7 +188,7 @@ test('a release that arrives while the speculative start is still in flight stop
   });
   mockAcquireXcodebuildSimulatorSetRedirect.mockImplementation(async () => {
     await gate;
-    return { release: mockRedirectRelease, releaseBestEffort: mockRedirectRelease };
+    return redirectHandle;
   });
 
   const starting = ensureRunnerSession(device, { speculative: true });
@@ -218,7 +214,7 @@ test('a release that waits out a demanded start leaves that runner alone', async
   });
   mockAcquireXcodebuildSimulatorSetRedirect.mockImplementation(async () => {
     await gate;
-    return { release: mockRedirectRelease, releaseBestEffort: mockRedirectRelease };
+    return redirectHandle;
   });
 
   const starting = ensureRunnerSession(device, {});

packages/platform-apple/src/runner/__tests__/runner-session-stale-bundles.test.ts

@@ -6,6 +6,7 @@ import {
   makeBackgroundRunner,
   makeClassifyOwnerLivenessViaMocks,
   runnerResponse,
+  redirectHandle,
 } from './runner-session-fixtures.ts';
 import { mkdtempForTestSync } from './tmp-dir.ts';
 
@@ -28,7 +29,6 @@ const {
   mockSignalPidsBestEffort,
   mockSignalProcessGroupBestEffort,
   mockWaitForRunner,
-  mockRedirectRelease,
 } = vi.hoisted(() => ({
   mockAcquireXcodebuildSimulatorSetRedirect: vi.fn(),
   mockCleanupTempFile: vi.fn(),
@@ -56,7 +56,6 @@ const {
   mockSignalPidsBestEffort: vi.fn(),
   mockSignalProcessGroupBestEffort: vi.fn(),
   mockWaitForRunner: vi.fn(),
-  mockRedirectRelease: vi.fn(),
 }));
 
 vi.mock('../runner-io.ts', async () => {
@@ -146,10 +145,7 @@ beforeEach(async () => {
   });
   mockResolveExpectedRunnerCacheMetadata.mockReturnValue({ schemaVersion: 1 });
   mockResolveRunnerDerivedPath.mockReturnValue('/tmp/derived');
-  mockAcquireXcodebuildSimulatorSetRedirect.mockResolvedValue({
-    release: mockRedirectRelease,
-    releaseBestEffort: mockRedirectRelease,
-  });
+  mockAcquireXcodebuildSimulatorSetRedirect.mockResolvedValue(redirectHandle);
   mockRunCmdBackground.mockReturnValue(makeBackgroundRunner(4242));
   mockRunAppleToolCommand.mockResolvedValue({ exitCode: 0, stdout: '', stderr: '' });
   mockIsProcessAlive.mockReturnValue(true);

packages/platform-apple/src/runner/__tests__/runner-session.test.ts

@@ -15,6 +15,8 @@ import {
   makeRunnerSession,
   runnerError,
   runnerResponse,
+  redirectHandle,
+  redirectRelease,
 } from './runner-session-fixtures.ts';
 import { mkdtempForTestSync } from './tmp-dir.ts';
 
@@ -37,7 +39,6 @@ const {
   mockSignalPidsBestEffort,
   mockSignalProcessGroupBestEffort,
   mockWaitForRunner,
-  mockRedirectRelease,
 } = vi.hoisted(() => ({
   mockAcquireXcodebuildSimulatorSetRedirect: vi.fn(),
   mockCleanupTempFile: vi.fn(),
@@ -67,7 +68,6 @@ const {
   mockSignalPidsBestEffort: vi.fn(),
   mockSignalProcessGroupBestEffort: vi.fn(),
   mockWaitForRunner: vi.fn(),
-  mockRedirectRelease: vi.fn(),
 }));
 
 // Fixed owner-identity value shared by the readProcessStartTime override
@@ -192,10 +192,7 @@ beforeEach(async () => {
   });
   mockResolveExpectedRunnerCacheMetadata.mockReturnValue({ schemaVersion: 1 });
   mockResolveRunnerDerivedPath.mockReturnValue('/tmp/derived');
-  mockAcquireXcodebuildSimulatorSetRedirect.mockResolvedValue({
-    release: mockRedirectRelease,
-    releaseBestEffort: mockRedirectRelease,
-  });
+  mockAcquireXcodebuildSimulatorSetRedirect.mockResolvedValue(redirectHandle);
   mockRunCmdBackground.mockReturnValue(makeBackgroundRunner(4242));
   mockRunAppleToolCommand.mockResolvedValue({ exitCode: 0, stdout: '', stderr: '' });
   mockIsProcessAlive.mockReturnValue(true);
@@ -703,10 +700,7 @@ test('runner session emits XCTest startup progress only after a runner rebuild',
     xctestrunPath: '/tmp/session-runner.xctestrun',
     jsonPath: '/tmp/session-runner.json',
   });
-  mockAcquireXcodebuildSimulatorSetRedirect.mockResolvedValue({
-    release: mockRedirectRelease,
-    releaseBestEffort: mockRedirectRelease,
-  });
+  mockAcquireXcodebuildSimulatorSetRedirect.mockResolvedValue(redirectHandle);
   mockRunCmdBackground.mockReturnValue(makeBackgroundRunner(4242));
   mockWaitForRunner.mockResolvedValue(runnerResponse({ uptimeMs: 1 }));
 
@@ -857,7 +851,7 @@ test('shutdown detach keeps scoped simulator-set runner sessions for the kill pa
   // XCTestDevices symlink; detach never releases the redirect itself.
   assert.equal(detached, 0);
   assert.ok(getRunnerSessionSnapshot(device.id));
-  assert.equal(mockRedirectRelease.mock.calls.length, 0);
+  assert.equal(redirectRelease.mock.calls.length, 0);
 });
 
 test('runner session startup kills legacy ownerless xcodebuild before launching a new runner', async () => {
@@ -1471,7 +1465,7 @@ test('runner session restarts dead runner without graceful shutdown', async () =
     ['/tmp/session-runner.xctestrun'],
     ['/tmp/session-runner.json'],
   ]);
-  assert.equal(mockRedirectRelease.mock.calls.length, 1);
+  assert.equal(redirectRelease.mock.calls.length, 1);
 });
 
 test('runner session stop kills only owned stale xcodebuild runner processes without in-memory session', async () => {
@@ -1510,7 +1504,7 @@ test('runner session abort removes owned lease for in-memory sessions', async ()
     ['/tmp/session-runner.xctestrun'],
     ['/tmp/session-runner.json'],
   ]);
-  assert.equal(mockRedirectRelease.mock.calls.length, 1);
+  assert.equal(redirectRelease.mock.calls.length, 1);
 });
 
 function isXcodebuildPkillCall(call: unknown[]): boolean {
@@ -1552,7 +1546,7 @@ test('runner session invalidation skips graceful shutdown and removes stale sess
     ['/tmp/session-runner.xctestrun'],
     ['/tmp/session-runner.json'],
   ]);
-  assert.equal(mockRedirectRelease.mock.calls.length, 1);
+  assert.equal(redirectRelease.mock.calls.length, 1);
   assert.equal(getRunnerSessionSnapshot(device.id), null);
 });