[TAN-8455] Flaky E2E Fix: language_switch.cy.ts — await builder boot

[Stef-Rousset]

This PR has been generated by Claude using the fix-flaky-e2e skill.

Changelog

Technical

• Fixed the flaky language_switch.cy.ts E2E spec. It now waits for the project
  page builder to finish booting before interacting with the toolbox, restores the
  login cookie before the per-test locale reset, and saves the layout after
  deleting a widget so the live-page assertions verify something real.

---

Generated by Claude

Spec: front/cypress/e2e/project_description_builder/language_switch.cy.ts

Root cause

Three separate defects, all confirmed by running rather than by inspection:

1. Test isolation vs. the beforeEach locale reset. testIsolation defaults to
   true (Cypress 15), so cookies are cleared and the page is reset to about:blank
   before every test after the first. apiUpdateCurrentUser early-returns when the
   cl2_jwt cookie is missing, so switchLocale('en') in beforeEach silently did
   nothing, cy.reload() reloaded a blank page, and setAdminLoginCookie() ran
   after the reload. The tolerant /Language \d text\./ matcher in the delete test
   was a workaround for this broken reset.

2. The nightly flake. The first test relied on the page before() visited
   surviving into the test, reloaded it, then immediately queried
   #e2e-draggable-text. ProjectPageBuilderPage renders null until the tenant
   locales and layout query resolve, so a slow boot under CI contention blew the
   15s default timeout — matching the nightly failure exactly
   (Expected to find element: #e2e-draggable-text, but never found it).

3. The delete test asserted nothing. It deleted a widget but never saved (the
   builder has no autosave), then asserted should('not.exist') on the live page
   immediately after a reload — passing by racing a blank page. Adding only a
   positive control, with no other change, turns it red:
   Expected not to find content: 'Language 1 text.' but continuously found it.

Why this addresses the cause rather than suppressing it

• The builder gate is #e2e-project-page-content-builder-page, the container that
  renders only once the app's own readiness condition is met — not a sleep. The
  explicit 60s budget covers admin-bundle boot on a contended node.
• The login cookie is restored before anything that reads it, so the locale reset
  actually happens instead of failing silently.
• switchLocale asserts the URL locale prefix afterwards. The user's locale wins
  over the URL's in utils/locale.ts, and the app rewrites the prefix — so the
  assertion proves the switch was applied.
• The delete is persisted and each not.exist is preceded by asserting the project
  title is visible, so absence means absence.
• No bare cy.wait(<ms>) was added, no assertions loosened, no retries relied on.
  The two pre-existing cy.wait(1000) calls guarding the craftjs debounce are
  untouched.

Stability evidence

• Local: 10/10 green with retries=0 (Cypress's 2 retries disabled, so these are
  first-attempt passes). The first attempt at this fix scored 2/10 and was discarded —
  a cy.intercept + cy.wait gate tripped on cy.wait's 5s request timeout.
• CI: pipeline 346670,
  spec ×3 — 3/3 nodes green, 6/6 test records success.
• Nightly history: 1 failure in the last 60 runs (2026-07-22), so the trend over the
  next few weeks is the real verdict.

[notion-workspace]

Fix/project-description-builder-language-switch

[cl-dev-bot]

	Messages
📖	Changelog provided 🎉
📖	Notion issue: TAN-8455
📖	Run the e2e tests
📖	Check translation progress

Generated by 🚫 dangerJS against f1070af

[amanda-anderson]

Code LGTM!