test-i18n-usage

Localization and locale-sensitive tests

Apply these checks to changed locale objects, translation call sites and their tests. Client-specific query conventions remain in the repository overlay.

Removing a translation call or its wrapper requires checking the affected keys and tests.

• Duplicate JSON keys shadow new copy: Verify the containing locale object has one definition and search rendered copy across every test layer. A test accommodating duplicate labels may hide an ambiguous product label.
• Source-language translations — keep user-facing copy behind translation helpers and update only the source-language file (locales/languages/en.json on Mobile; app/_locales/en/messages.json on Extension). The translation pipeline fills other locales; missing non-English strings are never a finding.
• Orphaned locale keys — when a PR deletes a function that called strings(...), grep for the keys it used (e.g. rg 'order_card\.(take_profit|stop|open_limit|close_limit)' app). Dead keys accumulate silently and bloat the translation pipeline; flag them even when runtime is unaffected.
• Test revert-sensitivity for locale keys — mocked strings implementations that fall back to || key render the raw key when a key goes stale, so an exact getByText assertion still fails on revert. Confirm that fallback exists before accepting a test as regression-proof; do not assume it.