[adimoldovan]

Trac ticket: https://core.trac.wordpress.org/ticket/66392

The parallel project ran the tests in one spec file in order, so only tests in different files ran at the same time. This PR turns on fullyParallel for that project, so tests in the same file also run at the same time. The serial and all projects do not change.

Two specs had tests that broke each other when they ran at the same time:

• classic-menus.test.js deleted every menu before each test. Each test now creates menus with a unique name and deletes only those. Both tests hold a new NAV_MENU_LOCATIONS lock, because all menu locations are one shared theme setting. Assigning a menu and deleting any menu both write it.
• In privacy.test.js, two runs of the privacy page test both wrote the page_for_privacy_policy setting. One run then read the other run's page ID. The test now holds a new PRIVACY_POLICY_PAGE lock, because one setting cannot be scoped to a test.

The README now says that tests in one file can also collide.

Testing Instructions

1. Run npm run test:e2e -- --project=parallel --shuffle --repeat-each=3. All tests pass.
2. Run grep -rn "{ lock:" tests/e2e/specs/. Each lock uses a constant from tests/e2e/utils/locks.js.

Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Claude Opus 5.5
Used for: Code change, test runs and this description.

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[Copilot]

🟢 Approval recommended

No active review issues remain for the change enabling same-file concurrency in the E2E parallel project.

No open issues 🎉

What changed in this PR

Enables tests within the same spec file to run concurrently in the E2E suite’s parallel project, while leaving serial and all unchanged.

Changes:

• Enables fullyParallel for the parallel project.
• Isolates classic-menu test data and adds locks for shared menu-location and privacy-page settings.
• Updates guidance on same-file test collisions and describe-group locks.

File	Description
tests/​e2e/​utils/​locks.js	Adds menu-location and privacy-page lock constants.
tests/​e2e/​specs/​privacy.test.js	Locks tests that change the privacy-page setting.
tests/​e2e/​specs/​classic-menus.test.js	Uses unique menu names, scoped cleanup, and a menu-location lock.
tests/​e2e/​README.md	Documents same-file concurrency and lock behavior.
tests/​e2e/​playwright.config.js	Enables full parallelism in the parallel project.

_{Review effort: Balanced}

[lancewillett]

The targeted menu/privacy runs passed all 12 executions with four workers, three repetitions and zero retries. Scoped menu cleanup preserved an unrelated menu and its secondary location. Removing only the privacy lock reproduced competing-setting failures; restoring it passed.

The configuration keeps the serial and all projects unchanged, and the existing shared-setting locks cover the affected writes. All four E2E CI jobs passed, with no reported retries. No blockers found.

_{AI review · gpt-6}

[lancewillett]

PR #15929 landed in https://core.trac.wordpress.org/changeset/65439