fix(@angular-devkit/build-angular): enable locale data transform for single localization

Author: clydin

packages/angular_devkit/build_angular/src/utils/i18n-options.ts

@@ -80,7 +80,7 @@ export function createI18nOptions(
     Object.keys(i18n.locales).forEach(locale => i18n.inlineLocales.add(locale));
   } else if (inline) {
     for (const locale of inline) {
-      if (!i18n.locales[locale]) {
+      if (!i18n.locales[locale] && i18n.sourceLocale !== locale) {
         throw new Error(`Requested inline locale '${locale}' is not defined for the project.`);
       }
 
@@ -146,6 +146,12 @@ export async function configureI18nBuild<T extends BrowserBuilderSchema | Server
     if (usedFormats.size > 0) {
       buildOptions.i18nFormat = [...usedFormats][0];
     }
+
+    // If only one locale is specified set the deprecated option to enable the webpack plugin
+    // transform to register the locale directly in the output bundle.
+    if (i18n.inlineLocales.size === 1) {
+      buildOptions.i18nLocale = [...i18n.inlineLocales][0];
+    }
   }
 
   // If inlining store the output in a temporary location to facilitate post-processing

tests/legacy-cli/e2e/tests/i18n/ivy-localize-dl.ts

@@ -39,6 +39,7 @@ export default async function() {
     const appArchitect = appProject.architect || appProject.targets;
     const serveConfigs = appArchitect['serve'].configurations;
     const e2eConfigs = appArchitect['e2e'].configurations;
+    const buildConfigs = appArchitect['build'].configurations;
 
     // Make default builds prod.
     appArchitect['build'].options.optimization = true;
@@ -63,6 +64,8 @@ export default async function() {
       } else {
         i18n.locales[lang] = `src/locale/messages.${lang}.xlf`;
       }
+
+      buildConfigs[lang] = { localize: [lang] };
       serveConfigs[lang] = { browserTarget: `test-project:build:${lang}` };
       e2eConfigs[lang] = {
         specs: [`./src/app.${lang}.e2e-spec.ts`],
@@ -142,6 +145,11 @@ export default async function() {
     }
   }
 
+  // Verify locale data registration (currently only for single locale builds)
+  await ng('build', '--optimization', 'false', '-c', 'fr', '--i18n-missing-translation', 'error');
+  await expectFileToMatch(`${baseDir}/fr/main-es5.js`, 'registerLocaleData');
+  await expectFileToMatch(`${baseDir}/fr/main-es2015.js`, 'registerLocaleData');
+
   // Verify missing translation behaviour.
   await appendToFile('src/app/app.component.html', '<p i18n>Other content</p>');
   await ng('build', '--i18n-missing-translation', 'ignore');