# Headless proof for [#20825](https://github.com/pingdotgg/t3code/pull/20825) Head: `1b3b634297c4f12ead8d0325e6ba1e14c5e9b852`. Linux / Node 24. This executes the production mobile checkout helper against the real GitVcsDriver service, with JSON round-trip and VcsListRefsResult schema decoding. It uses disposable local Git repositories, bare remotes and linked worktrees. It does not mount React/native UI, send WebSocket requests, submit drafts or start an agent. Older-server behavior is simulated by dropping the optional isAtRepositoryRoot field after schema decoding. The mismatched-upstream scenario is a separate static fixture phase with a new service runtime, avoiding dependence on expiry of the existing refresh-coalescing cache. Reused/rejected selections never switch the original checkout; its main branch and contents are asserted unchanged. The mismatched remote and freed historical branch use production switchRef, with null worktree overrides. A stale historical path never survives a successful checkout. The held worktree retains its contents, including after it moves to another branch to free the historical branch. Native iOS/Android, macOS/Windows and Electron remain unverified. No layout change is claimed. Run: `node --experimental-transform-types --import /tmp/worktree-git-11b/register-loader.mjs /tmp/worktree-git-11b/headless-proof.mjs`. The loader only resolves extensionless relative TypeScript imports for Node; production modules execute directly. This proof script and both loader files live outside the checkout. ## Production service and helper output ```json { "head": "1b3b634297c4f12ead8d0325e6ba1e14c5e9b852", "transport": "in-process real GitVcsDriver -> JSON and VcsListRefsResult schema -> production mobile helper", "uiVerified": false, "scenarios": [ { "scenario": "root project, historical branch", "outcome": "selected", "branch": "feature/a", "worktreePath": "/tmp/20825-headless-eNRI0d/held" }, { "scenario": "root project, direct picker", "outcome": "selected", "branch": "feature/a", "worktreePath": "/tmp/20825-headless-eNRI0d/held" }, { "scenario": "matching slash-containing remote", "outcome": "selected", "branch": "feature/a", "worktreePath": "/tmp/20825-headless-eNRI0d/held" }, { "scenario": "symlinked root project, direct picker", "outcome": "selected", "branch": "feature/a", "worktreePath": "/tmp/20825-headless-eNRI0d/held" }, { "scenario": "nested project, historical", "outcome": "rejected", "message": "Error: This project is a repository subdirectory. Choose another branch or add the repository root as a project to reuse this worktree." }, { "scenario": "nested project, picker", "outcome": "rejected", "message": "Error: This project is a repository subdirectory. Choose another branch or add the repository root as a project to reuse this worktree." }, { "scenario": "older server missing root metadata", "outcome": "rejected", "message": "Error: The server did not report whether this project is at the repository root, so this worktree cannot be reused safely. Update the server or choose another branch." }, { "scenario": "nested project, already-current historical branch", "outcome": "selected", "branch": "main", "worktreePath": null }, { "scenario": "different upstream uses actual server switchRef", "outcome": "selected", "branch": "upstream/feature/a", "worktreePath": null }, { "scenario": "free historical branch clears its previous worktree path", "outcome": "selected", "branch": "feature/a", "worktreePath": null } ], "assertions": "all passed; reused/rejected paths never switched original checkout; mismatched-remote and free-branch fallbacks used real switchRef; held worktree contents unchanged" } ``` ## Nested/old-server before fix: 4 expected failures, 9 passed ```text note: You are running `vp test` as a Vite+ built-in command. If you meant to run the test npm script, use `vpr test` instead. RUN v5.0.1 /home/ubuntu/wt/worktree-git-11b ❯ apps/mobile/src/features/threads/checkout-new-task-branch.test.ts (13 tests | 4 failed) 2363ms ❯ new-task branch checkout (13) × rejects historical worktree reuse when project root is unsafe (nested: true) 99ms × rejects picker worktree reuse when project root is unsafe (nested: true) 77ms × rejects historical worktree reuse when project root is unsafe (nested: false) 87ms × rejects picker worktree reuse when project root is unsafe (nested: false) 77ms ⎯⎯⎯⎯⎯⎯⎯ Failed Tests 4 ⎯⎯⎯⎯⎯⎯⎯ FAIL apps/mobile/src/features/threads/checkout-new-task-branch.test.ts > new-task branch checkout > rejects historical worktree reuse when project root is unsafe (nested: true) FAIL apps/mobile/src/features/threads/checkout-new-task-branch.test.ts > new-task branch checkout > rejects picker worktree reuse when project root is unsafe (nested: true) FAIL apps/mobile/src/features/threads/checkout-new-task-branch.test.ts > new-task branch checkout > rejects historical worktree reuse when project root is unsafe (nested: false) FAIL apps/mobile/src/features/threads/checkout-new-task-branch.test.ts > new-task branch checkout > rejects picker worktree reuse when project root is unsafe (nested: false) AssertionError: expected 'Success' to be 'Failure' // Object.is equality Expected: "Failure" Received: "Success" ❯ apps/mobile/src/features/threads/checkout-new-task-branch.test.ts:351:27 349| "feature\n", 350| ); 351| expect(result._tag).toBe("Failure"); | ^ 352| if (result._tag !== "Failure") throw new Error("Expected unsafe … 353| if (nested) { ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/4]⎯ Test Files 1 failed (1) Tests 4 failed | 9 passed (13) Start at 22:44:19 Duration 5.19s (tests 47%, transform 33%, import 18%, setup 2%) ``` ## Symlink-root regression before server identity fix: 1 expected failure ```text note: You are running `vp test` as a Vite+ built-in command. If you meant to run the test npm script, use `vpr test` instead. RUN v5.0.1 /home/ubuntu/wt/worktree-git-11b ❯ apps/mobile/src/features/threads/checkout-new-task-branch.test.ts (14 tests | 1 failed | 13 skipped) 166ms ❯ new-task branch checkout (14) × reuses an occupied picker worktree when the project root is a symlink 163ms ⎯⎯⎯⎯⎯⎯⎯ Failed Tests 1 ⎯⎯⎯⎯⎯⎯⎯ FAIL apps/mobile/src/features/threads/checkout-new-task-branch.test.ts > new-task branch checkout > reuses an occupied picker worktree when the project root is a symlink AssertionError: Error: This project is a repository subdirectory. Choose another branch or add the repository root as a project to reuse this worktree.: expected 'Failure' to be 'Success' // Object.is equality Expected: "Success" Received: "Failure" ❯ apps/mobile/src/features/threads/checkout-new-task-branch.test.ts:242:7 240| result._tag, 241| result._tag === "Failure" ? String(squashAtomCommandFailure(resu… 242| ).toBe("Success"); | ^ 243| if (result._tag !== "Success") throw new Error("Symlink-root workt… 244| expect(result.value.worktreePath).toBe(worktreePath); ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/1]⎯ Test Files 1 failed (1) Tests 1 failed | 13 skipped (14) Start at 22:52:25 Duration 2.41s (transform 55%, import 34%, tests 7%, setup 4%) ``` ## Stale historical worktree path before fix: 1 expected failure ```text note: You are running `vp test` as a Vite+ built-in command. If you meant to run the test npm script, use `vpr test` instead. RUN v5.0.1 /home/ubuntu/wt/worktree-git-11b ❯ apps/mobile/src/features/threads/checkout-new-task-branch.test.ts (14 tests | 1 failed | 13 skipped) 139ms ❯ new-task branch checkout (14) × switches to a free branch and clears its historical worktree path 137ms ⎯⎯⎯⎯⎯⎯⎯ Failed Tests 1 ⎯⎯⎯⎯⎯⎯⎯ FAIL apps/mobile/src/features/threads/checkout-new-task-branch.test.ts > new-task branch checkout > switches to a free branch and clears its historical worktree path AssertionError: expected '/tmp/t3-branch-selection-wmhYAZ/previ…' to be null - Expected: null + Received: "/tmp/t3-branch-selection-wmhYAZ/previous-worktree" ❯ apps/mobile/src/features/threads/checkout-new-task-branch.test.ts:153:39 151| expect(result.value.name).toBe("feature/a"); 152| expect(result.value.current).toBe(true); 153| expect(result.value.worktreePath).toBeNull(); | ^ 154| expect((await git("branch", "--show-current")).stdout.trim()).toBe… 155| expect(await NodeFSP.readFile(NodePath.join(cwd, "file.txt"), "utf… ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/1]⎯ Test Files 1 failed (1) Tests 1 failed | 13 skipped (14) Start at 23:09:42 Duration 2.48s (transform 57%, import 32%, tests 6%, setup 5%) ``` ## Mobile after all fixes plus neighbors: 41 passed ```text note: You are running `vp test` as a Vite+ built-in command. If you meant to run the test npm script, use `vpr test` instead. RUN v5.0.1 /home/ubuntu/wt/worktree-git-11b Test Files 3 passed (3) Tests 41 passed (41) Start at 23:09:53 Duration 3.85s (transform 42%, tests 27%, import 27%, setup 4%) Transform transforming modules took 2.74s · 42% of tracked time, re-done on every run persist transforms across runs with fsModuleCache: true learn more: https://vitest.dev/guide/improving-performance#caching-between-reruns ``` ## Server before boolean metadata: 1 expected failure, 7 passed ```text note: You are running `vp test` as a Vite+ built-in command. If you meant to run the test npm script, use `vpr test` instead. RUN v5.0.1 /home/ubuntu/wt/worktree-git-11b stdout | apps/server/src/vcs/GitVcsDriverCore.test.ts > GitVcsDriver core integration > refName operations > lists root and upstream metadata and optionally includes matching remote refs [22:53:07.316] ERROR (#21): Error [AssertionError]: expected [ { …(6) }, { …(6) } ] to deeply equal [ { …(7) }, { …(7) } ] at /home/ubuntu/wt/worktree-git-11b/apps/server/src/vcs/GitVcsDriverCore.test.ts:3281:16 { actual: [ { rootPath: '/tmp/git-vcs-driver-worktree-QJrBhM', refs: [Array], isRepo: true, hasPrimaryRemote: true, nextCursor: null, totalCount: 5 }, { rootPath: '/tmp/git-vcs-driver-worktree-QJrBhM', refs: [Array], isRepo: true, hasPrimaryRemote: true, nextCursor: null, totalCount: 4 } ], expected: [ { rootPath: '/tmp/git-vcs-driver-worktree-QJrBhM', refs: [Array], isRepo: true, hasPrimaryRemote: true, nextCursor: null, totalCount: 5, isAtRepositoryRoot: false }, { rootPath: '/tmp/git-vcs-driver-worktree-QJrBhM', refs: [Array], isRepo: true, hasPrimaryRemote: true, nextCursor: null, totalCount: 4, isAtRepositoryRoot: true } ], showDiff: true, operator: 'deepStrictEqual', [cause]: undefined } ❯ apps/server/src/vcs/GitVcsDriverCore.test.ts (176 tests | 1 failed | 168 skipped) 2708ms ❯ GitVcsDriver core integration (133) ❯ refName operations (8) × lists root and upstream metadata and optionally includes matching remote refs 969ms ⎯⎯⎯⎯⎯⎯⎯ Failed Tests 1 ⎯⎯⎯⎯⎯⎯⎯ FAIL apps/server/src/vcs/GitVcsDriverCore.test.ts > GitVcsDriver core integration > refName operations > lists root and upstream metadata and optionally includes matching remote refs AssertionError: expected [ { …(6) }, { …(6) } ] to deeply equal [ { …(7) }, { …(7) } ] - Expected + Received @@ -1,9 +1,8 @@ [ { "hasPrimaryRemote": true, - "isAtRepositoryRoot": false, "isRepo": true, "nextCursor": null, "refs": [ { "current": true, @@ -48,11 +47,10 @@ "rootPath": "/tmp/git-vcs-driver-worktree-QJrBhM", "totalCount": 5, }, { "hasPrimaryRemote": true, - "isAtRepositoryRoot": true, "isRepo": true, "nextCursor": null, "refs": [ { "current": true, ❯ apps/server/src/vcs/GitVcsDriverCore.test.ts:3281:16 3279| { ...aliased, isAtRepositoryRoot: true }, 3280| ]; 3281| assert.deepEqual([complete, aliased], expected); | ^ 3282| assert.deepEqual( 3283| [decodeVcsListRefsResult(complete), decodeVcsListRefsResult(… ❯ IteratorImpl.~effect/Effect/successCont node_modules/.pnpm/effect@4.0.5/node_modules/effect/src/internal/effect.ts:1422:28 ❯ ExitPrimitive.~effect/Effect/evaluate node_modules/.pnpm/effect@4.0.5/node_modules/effect/src/internal/core.ts:585:30 ❯ FiberImpl.runLoop node_modules/.pnpm/effect@4.0.5/node_modules/effect/src/internal/effect.ts:654:41 ❯ FiberImpl.evaluate node_modules/.pnpm/effect@4.0.5/node_modules/effect/src/internal/effect.ts:595:23 ❯ FiberImpl.evaluate node_modules/.pnpm/effect@4.0.5/node_modules/effect/src/internal/effect.ts:589:27 ❯ Array. node_modules/.pnpm/effect@4.0.5/node_modules/effect/src/internal/effect.ts:1159:17 ❯ FiberImpl.evaluate node_modules/.pnpm/effect@4.0.5/node_modules/effect/src/internal/effect.ts:618:21 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/1]⎯ Test Files 1 failed (1) Tests 1 failed | 7 passed | 168 skipped (176) Start at 22:53:02 Duration 6.70s (tests 42%, transform 40%, import 16%, setup 2%) Transform transforming modules took 2.58s · 40% of tracked time, re-done on every run persist transforms across runs with fsModuleCache: true learn more: https://vitest.dev/guide/improving-performance#caching-between-reruns ``` ## Server after all fixes and junction fixture: 8 passed ```text note: You are running `vp test` as a Vite+ built-in command. If you meant to run the test npm script, use `vpr test` instead. RUN v5.0.1 /home/ubuntu/wt/worktree-git-11b Test Files 1 passed (1) Tests 8 passed | 168 skipped (176) Start at 22:56:20 Duration 5.15s (tests 47%, transform 33%, import 17%, setup 2%) ``` ## Other verification 25 shared VCS/action tests passed. Mobile, contracts, client-runtime and server typechecks passed. Scoped lint and formatting passed; four pre-existing lint warnings remain. Original mobile suite: 11 cases; rebuilt suite: 14 cases, including 4 nested/old-server rows and one symlink-root case. The existing checkout case also verifies a stale historical worktree path is cleared after successful checkout. Existing server test extended in place; no server case added. No full repository suite was run. Independent review records are tracked separately.