Verify Language Switch

A translated heading is not a translated page

Clicking the language menu and seeing one word change proves one string was wired up. It does not prove the rest of the page followed, that the field the user was in the middle of filling still holds what they typed, or that the choice outlives a refresh. Those are three separate bugs. Each ships regularly, and glancing at the page after the click catches none of them.

Reticle can prove all three in the running app, with no test code. Not installed? RETICLE_INSTALL_SOURCE=npx_skill npx @reticlehq/server@latest init, then the install-and-verify skill.

Before you start

• Confirm the session can observe: reticle_session({ action: "list" }). A hidden or throttled tab can accept a click and render nothing. If it is not healthy, report the run as blocked, not passed.
• Take the expected strings from the app, not from your head. Open its translation files (locales/, messages/, i18n/) and copy the target-language value for each string you will assert on. A translation you guessed can fail on a correct app, and one you half-remember can pass on a wrong one.
• Pick strings that are not already on the page. A language menu that lists "Español" satisfies { kind: "text", contains: "Español" } before you click, and the verdict comes back already_true. Assert on the translated heading or a nav label instead, and scope the predicate to the region it lives in.

1. Note what is on screen, and type something

reticle_look({ action: "page", sessionId })

Write down two or three visible strings in the current language from different regions of the page: the heading, a nav label, a button. One string proves one component; two regions prove the switch reached the page.

Then type a value into a form field, so step 3 has something to find:

reticle_look({ action: "page", sessionId, mode: "interactive" })
reticle_act({ sessionId, ref: "<a text field>", action: "fill", args: { value: "reticle-i18n-4471" } })

The result must show valueChanged: true. Use a value nothing else on the page contains, so step 3 proves this input survived rather than a default being refilled.

2. Switch, and name what must change before you act

Get the switch control's ref from the interactive look. A <select> takes action: "select" with { value }; a button or menu item takes click.

reticle_act_and_wait({ sessionId, ref: "<language control>", action: "select", args: { value: "es" }, until: { kind: "allOf", predicates: [
  { kind: "text", contains: "<heading in the new language>", scope: "h1" },
  { kind: "text", contains: "<heading in the old language>", absent: true },
  { kind: "text", contains: "<nav label in the new language>", scope: "nav" },
  { kind: "text", contains: "<the heading's translation key, e.g. home.title>", absent: true },
  { kind: "console", level: "error", absent: true },
]}})

Each clause catches a different bug. New text present and old text absent proves the switch replaced the string rather than rendering both. The second region proves it was not one component. The translation-key clause catches the string that fell back to its key because the target locale is missing it. The console clause catches the i18n library reporting a missing key as an error. If yours reports at warn, add { kind: "console", level: "warn", contains: "missing", absent: true }.

If the app stores the choice on the server, add { kind: "net", urlContains: "/api/preferences", ok: true } with the app's real endpoint, so a switch that only changed the client is not reported as saved.

If the switch is a full page load (a ?lang=es query or an /es/ prefix that reloads the document), the SDK is torn down mid-wait and this verdict will be unknown. Use reticle_navigate({ sessionId, url: "<the app's origin>/es/<route>" }) and run the text assertions on the session that comes back. Then report step 3 as lost by design: a switch that reloads the document discards the user's typed input, and that is a finding, not a pass.