Split eager English i18n shell

[koala73]

Summary

• Replace the static full en.json import in src/services/i18n.ts with an eager en.shell.json subset.
• Keep full en.json lazy-loadable through the locale glob and preload it after English startup; non-English startup still loads the requested locale plus full English fallback before switching languages.
• Add a focused regression test for the English shell split and required eager translation surface.

Issue

Fixes #3535.

Validation

• node --test tests/i18n-english-shell.test.mjs passed.
• node --test tests/country-brief-i18n.test.mjs passed.
• npm run typecheck passed.
• git diff --check passed.
• npm run build passed.
• Pre-push hook passed: typecheck, API typecheck, boundary checks, edge bundle check, full unit suite (10331 tests, 0 failures), edge function tests, markdown lint, MDX lint, pro-test bundle freshness, version sync.

Bundle evidence

• src/locales/en.json: 135,820 bytes; new eager src/locales/en.shell.json: 48,175 bytes.
• Build emitted full English separately as dist/assets/en-WYH83nI7.js (110.14 kB, gzip 39.50 kB).
• dist/index.html modulepreloads i18n-qlunRAMb.js, not en-*.js.
• Full-only string probe (Country Facts) is present only in dist/assets/en-WYH83nI7.js, not entry/i18n/panels chunks.

Remaining risk

• The shell subset is conservative and still broad enough for eager chrome/panel strings; future eager translations need to be covered by tests/i18n-english-shell.test.mjs or moved out of first-paint paths.

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Project	Deployment	Actions	Updated (UTC)
worldmonitor	Ready	Preview, Comment	Jun 1, 2026 11:14am

[greptile-apps]

Greptile Summary

This PR splits the monolithic en.json (~136 KB) eager import into a curated en.shell.json (~48 KB) subset for first-paint, deferring the full English dictionary to a lazy load. English users now get the shell bundle synchronously and the full bundle preloaded fire-and-forget; non-English users continue to await both their locale and the full English fallback before initI18n resolves.

• src/locales/en.shell.json: New 794-line subset containing all shell/chrome-level strings (header, panels, common, auth, mcp, widgets, etc.) plus all component tooltips; values are verified by test to be identical to en.json.
• src/services/i18n.ts: Replaces the static en.json import, updates the locale glob exclusion, removes the pre-seeded loadedLanguages.add('en'), and introduces preloadEnglishTranslation() as a non-blocking post-init kick for English users.
• tests/i18n-english-shell.test.mjs: New regression guard checking that the static import was removed, the shell stays under 50 KB, and all required eager-chrome keys exist in the shell with values matching en.json.

Confidence Score: 4/5

Safe to merge; the shell split is well-validated by the new test and the non-English path is unchanged and fully awaited.

The logic change is clean and the core non-English path is unaffected. The two concerns are both non-blocking: the fire-and-forget preload for English leaves a brief window where non-shell keys could show as missing with no automatic re-render, and the test's non-recursive directory scan may not cover panel subcomponents. Neither is a confirmed breakage given the shell is designed to cover all first-paint strings and the build evidence checks out.

tests/i18n-english-shell.test.mjs — the eager-chrome file scan is non-recursive and may not cover all panel component files if any live in subdirectories.

Important Files Changed

Filename	Overview
src/locales/en.shell.json	New eager-load English subset (~48 KB) covering shell, header, panels, common, connectivity, premium, auth, mcp, widgets, countryBrief, contextMenu, components, modals, and popups. Values are verified by the new test to match en.json exactly.
src/services/i18n.ts	Replaces static en.json import with en.shell.json; English users now get the shell eagerly and full English preloaded fire-and-forget. Non-English users still await both their locale and full English before returning. Fire-and-forget preload is intentional but means non-shell keys on English paths may briefly be absent until the preload resolves, and no re-render is triggered automatically when addResourceBundle completes.
tests/i18n-english-shell.test.mjs	New regression test validating that en.json is no longer statically imported, the shell stays under 50 KB, and shell key values match en.json. Uses readdirSync (non-recursive) for eager chrome files, so components in subdirectories of src/components/ are not checked.

Sequence Diagram

sequenceDiagram
    participant App
    participant initI18n
    participant i18next
    participant localeModules

    App->>initI18n: initI18n()
    initI18n->>i18next: "init({ resources: { en: shellTranslation } })"
    i18next-->>initI18n: initialized (shell bundle only)

    alt English detected
        initI18n->>initI18n: preloadEnglishTranslation() [fire-and-forget]
        initI18n-->>App: returns (shell active)
        Note over App,localeModules: Components render with shell keys only
        initI18n->>localeModules: import('../locales/en.json') [async]
        localeModules-->>initI18n: full English dictionary
        initI18n->>i18next: addResourceBundle('en', fullDict, deep, overwrite)
        Note over i18next: Full English merged in, no re-render triggered
    else Non-English detected
        initI18n->>localeModules: "import('../locales/${lang}.json') [await]"
        localeModules-->>initI18n: locale translation
        initI18n->>localeModules: import('../locales/en.json') [await]
        localeModules-->>initI18n: full English (for fallback)
        initI18n->>i18next: changeLanguage(detectedLang)
        initI18n-->>App: returns (both bundles active)
    end

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Comments Outside Diff (1)

1. tests/i18n-english-shell.test.mjs, line 917-920 (link)

   Non-recursive directory scan may miss panel subcomponents

   readdirSync(COMPONENTS_DIR) only lists files directly inside src/components/ — it does not descend into subdirectories. If any panel subcomponent or helper file lives in a nested directory and calls t() with a key not present in the shell, neither the test nor the type-checker would catch the gap. The component would silently show a missing-key string for English users during the preload window, with no automatic re-render once the full bundle loads.

_{Reviews (1): Last reviewed commit: "fix(i18n): split eager English shell" | Re-trigger Greptile}

[greptile-apps]

Fire-and-forget preload leaves a stale-UI window for non-shell keys

preloadEnglishTranslation() is not awaited, so initI18n() returns while en.json is still in-flight. Any class-based component that renders between initI18n returning and the preload completing, and that calls t() with a key present in en.json but absent from en.shell.json, will receive the key name (missing translation). Since i18next.addResourceBundle does not emit a languageChanged event, there is no automatic mechanism to re-render those components once the full bundle lands — the stale value persists until the next independent re-render triggered by data or user interaction. The shell is designed to cover all first-paint strings, so this is largely mitigated by the test, but any gap in shell key coverage would be invisible at runtime.