Search Blocks: enable @wordpress/i18n in the IAPI view bundle (SEARCH-168)

[kangzj]

Fixes SEARCH-168

Why

A shopper using a screen reader on a non-English Jetpack Search store currently hears the product rating in English ("4.5 out of 5 stars based on 42 reviews") even though everything else on the page is translated. The fix gives the Interactivity API view bundle a real @wordpress/i18n it can call, so the rating aria-label — and every other JS-emitted view-bundle string — picks up the page locale on first paint.

This also unblocks any future Jetpack Search block code that wants to call __() / _n() / sprintf() directly instead of detouring through state.strings.* seeded from PHP.

Proposed changes

• Webpack — externalize @wordpress/i18n as a script module. tools/webpack.blocks.config.js now passes a requestToExternalModule callback that returns 'module @wordpress/i18n' so the IAPI bundle emits a hoisted static import * from "@wordpress/i18n" (same pattern DEP already uses for @wordpress/interactivity). DEP previously threw "Attempted to use WordPress script in a module" because core only registers @wordpress/interactivity (and a11y / router) as script modules.
• Tiny ESM shim at src/search-blocks/store/i18n-shim.js. Re-exports window.wp.i18n's methods (__, _x, _n, _nx, sprintf, isRTL, hasTranslation, setLocaleData) with identity fallbacks if wp-i18n somehow didn't load. Built as its own webpack entry → build/search-blocks/store/i18n-shim.js.
• PHP — register the shim under the canonical @wordpress/i18n module ID in Search_Blocks::register_i18n_module() via wp_register_script_module(). Browser's import map now resolves @wordpress/i18n to the shim.
• PHP — populate window.wp.i18n with the page locale. Search_Blocks::enqueue_i18n_runtime() enqueues the classic wp-i18n script and wp_add_inline_scripts a setLocaleData() call built from get_translations_for_domain( 'jetpack-search-pkg' ). Classic scripts run synchronously before deferred modules, so by the time the shim evaluates, window.wp.i18n.__() already knows the locale's translations. The JSON payload is encoded with JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT so a translation containing </script> can't break out of the inline tag.
• Use the new path in three view-bundle call sites:
  • result-utils.js buildRatingAriaLabel — the original SEARCH-168 offender. Now calls __( '%s out of 5 stars', ... ) for the no-reviews branch and _n( '%1$s out of 5 stars based on %2$d review', '%1$s out of 5 stars based on %2$d reviews', reviewCount, ... ) + sprintf for the with-reviews branch (matches the source strings the editor's edit.js already extracts).
  • store/index.js computeResultsCountText — drops the state.strings?.searching ?? 'Searching…' indirection in favour of native __/_n/sprintf.
  • active-filters/view.js activePills — same swap on the "Remove %s" pill aria-label.
• Drop the now-unused build_initial_strings() PHP seed and its test assertions. Strings live in JS source now.

Related product discussion/links

• Linear: SEARCH-168 (this fix), RSM-267 (predecessor that established the PHP-seeded state.strings.* workaround)
• Surfaced in: #48198 review thread and as Copilot suggestion Allow plugins to inject additional template-specific open graph tags #2 on #48509

Does this pull request change what data or activity we track or use?

No.

Testing instructions

1. Pull the branch and run the four-layer build matrix:

   pnpm jetpack build packages/my-jetpack
   pnpm jetpack build plugins/jetpack
   pnpm jetpack build packages/search
   pnpm jetpack build plugins/search
   

2. Unit tests:
   • cd projects/packages/search && pnpm run test-scripts — 416/416 JS tests pass.
   • cd projects/packages/search && composer phpunit -- --filter=Search_Blocks_Test — 18/18 PHP tests pass.
3. In the browser (any dev env where Jetpack Search blocks are enabled — e.g. with add_filter( 'jetpack_search_blocks_enabled', '__return_true' )):
   • Visit a page that uses any Jetpack Search 3.0 block (e.g. search-results).
   • In DevTools, open the page source and confirm the import map contains:

     "@wordpress/i18n":"http://.../jetpack-search/.../build/search-blocks/store/i18n-shim.js?ver=..."
     

   • In the console:

     wp.i18n.sprintf( wp.i18n._n( 'Found %d result', 'Found %d results', 5, 'jetpack-search-pkg' ), 5 )
     // → "Found 5 results"   (en_US — source string round-trips)
     // → translated equivalent on a non-English locale that has a .mo file

   • Run a search that returns hits — the count text below the input should read "Found N results" and update as you type. Source it from the new __/_n/sprintf path, not the old PHP-seeded state.strings.
   • If WC products are indexed, switch a search-results block to the product layout and inspect a card's rating row: the aria-label should now be the translated "X out of 5 stars based on N reviews" string (front end matches editor preview).

[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WoA dev site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin (Jetpack), and enable the echo/search-168-localize-rating-aria-label branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack echo/search-168-localize-rating-aria-label

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• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
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[github-actions]

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[kangzj]

Review-cycle summary — 3cf1b71 → ef8151e

2 round(s); CI green; both AI reviewers approved; 0 inline threads to resolve.

What changed during the cycle

Commits added:

• a74c2a5 — Search Blocks: enable @wordpress/i18n in the IAPI view bundle (SEARCH-168)
• ef8151e — Address review: docblock, test coverage, explicit DEP fall-through, changelog Type

Diff summary: 10 files changed, 335 insertions(+), 90 deletions(-)

Review threads addressed:

Source	Comment	Resolution
claude[bot]	(#IC_kwDOAOho7M8AAAABBVwvcA) inverted "first-wins" docblock; missing collect_locale_data() test coverage; explicit DEP fall-through; Plural-Forms casing; _nx fallback signature	Docblock rewritten to match actual semantics (ef8151e); build_locale_data_payload() extracted with two new PHPUnit cases; requestToExternalModule now leads with an explicit early-return; casing handled via ?? fallback to the Western 2-form rule; shim fallback signature scoped to the unreachable wp-i18n-missing case.
copilot-swe-agent	(#IC_kwDOAOho7M8AAAABBVyIQQ) same three actionable items + changelog Type: changed → Type: fixed	Same commit ef8151e; changelog Type updated.
claude[bot] (re-review)	(#IC_kwDOAOho7M8AAAABBV05Wg) "Ready to merge."	No action — confirmation.
copilot-swe-agent (re-review)	(#IC_kwDOAOho7M8AAAABBV1YTA) "Looks good to merge."	No action — confirmation.
jp-launch-control	(#IC_kwDOAOho7M8AAAABBVz1Cw) Code-coverage delta (-6.80% in class-search-blocks.php; new i18n-shim.js at 0/16)	Coverage check itself is pass. The drop is enqueue_i18n_runtime() / register_i18n_module() / collect_locale_data() wrapping WP registry functions (not unit-testable without a WP bootstrap), and i18n-shim.js is a browser-only ESM shim whose runtime path is exercised through result-utils.test.js / store.test.js against the real @wordpress/i18n npm package. Both reviewers explicitly accepted the gap as "no action needed."

Unaddressed (flagged for owner): None.

CI: all required checks passing (Test plugin upgrades is pending, deploy-preview only — not blocking).