angular-docs-cn/integration/ivy-i18n/e2e/README.md

## E2E tests

There are four different sets of e2e tests in this folder. They are all testing different
translation scenarios, but they are all built with IVY enabled.

### runtime

A new `polyfills.ts` file is provided (`polyfills-runtime.ts`) which is swapped in by a file
replacement in the `angular.json` configuration. In this new file:
 * Runtime translations are provided (`loadTranslations()`).
 * The current locale is set (`$localize.locale = 'fr'`) and loaded (`registerLocaleData(localeFr);`)

### de and fr

The application is built (into the `dist` folder) and then two sets of translations
(`src/locales/messages.(de|fr).json`) are used to generate two copies of the app, which have
been translated (compile-time inlined).

These translated apps are stored in `tmp/translations/(de|fr)`.

### legacy

The CLI `ng extract-i18n` tool extracts the messages from the Angular templates, into the XLIFF 1.2
format with legacy message ids (`tmp/legacy-locales/messages.legacy.xlf`).

The translation file is modified to apply a simple translation.

The app must be compiled using the `i18nLegacyMessageIdFormat` option set to ensure that the correct
message ids are used to match those in the translation files.

The app is translated using the compile-time inlining tool to generate a copy that has the
translated message in it.

## Hosting

Since the CLI hosts from and in-memory file-system the compile-time inliner is not able to
translate the output files. So the `de`, `fr` and `legacy` apps must be statically built to
disk and translated there.

Since the translated app is now on disk, we cannot use the CLI to serve it. Instead we use
a simple static HTTP server instead.