fix: resolve @angular/common/locales bare specifier

src/builders/build/builder.ts

@@ -48,7 +48,11 @@ import { checkForInvalidImports } from "./../../utils/check-for-invalid-imports.
 import { federationBuildNotifier } from "./federation-build-notifier.js";
 import type { NfBuilderSchema, NfInternalOptions } from "./schema.js";
 import { createAngularBuildAdapter } from "../../tools/esbuild/angular-esbuild-adapter.js";
-import { getI18nConfig, translateFederationArtifacts } from "./i18n.js";
+import {
+  getI18nConfig,
+  registerAngularLocaleDataInFederationConfig,
+  translateFederationArtifacts,
+} from "./i18n.js";
 import { updateScriptTags } from "./update-index-html.js";
 
 const originalWrite = process.stderr.write.bind(process.stderr);
@@ -289,6 +293,17 @@ export async function* runBuilder(
   );
   checkForInvalidImports(Object.keys(normalized.config.shared), "externals");
 
+  // Surface Angular's `@angular/common/locales/global/<code>` locale data
+  // through the federation config for non-English locales. Must run before
+  // `getExternals` so the entries are marked external and bundled/mapped.
+  const inlineLocaleFilter = Array.isArray(localeFilter) ? localeFilter : [];
+  registerAngularLocaleDataInFederationConfig(
+    normalized.config,
+    i18n,
+    context.workspaceRoot,
+    inlineLocaleFilter,
+  );
+
   const activateSsr = nfBuilderOptions.ssr && !nfBuilderOptions.dev;
 
   const start = process.hrtime();

src/builders/build/i18n-locale-data.spec.ts

@@ -0,0 +1,239 @@
+import * as fs from "fs";
+import * as os from "os";
+import * as path from "path";
+import {
+  logger,
+  type NormalizedFederationConfig,
+} from "@softarc/native-federation/internal";
+
+import {
+  registerAngularLocaleDataInFederationConfig,
+  resolveAngularLocaleData,
+  type I18nConfig,
+} from "./i18n.js";
+
+const warnSpy = vi.spyOn(logger, "warn").mockImplementation(() => undefined);
+
+afterEach(() => {
+  vi.clearAllMocks();
+});
+
+afterAll(() => {
+  warnSpy.mockRestore();
+});
+
+function makeFakeWorkspace(locales: string[], version = "22.0.0"): string {
+  const root = fs.mkdtempSync(path.join(os.tmpdir(), "nf-i18n-spec-"));
+  const globalDir = path.join(
+    root,
+    "node_modules",
+    "@angular",
+    "common",
+    "locales",
+    "global",
+  );
+  fs.mkdirSync(globalDir, { recursive: true });
+  for (const locale of locales) {
+    fs.writeFileSync(path.join(globalDir, `${locale}.js`), "/* fake */");
+  }
+  fs.writeFileSync(
+    path.join(root, "node_modules", "@angular", "common", "package.json"),
+    JSON.stringify({ name: "@angular/common", version }),
+  );
+  return root;
+}
+
+function emptyConfig(): NormalizedFederationConfig {
+  return {
+    $type: "classic",
+    name: "test",
+    exposes: {},
+    shared: {},
+    sharedMappings: {},
+    skip: { strings: new Set(), functions: [], regexps: [] },
+    chunks: false,
+    externals: [],
+    features: {
+      mappingVersion: false,
+      ignoreUnusedDeps: false,
+      denseChunking: false,
+      denseExternals: false,
+      integrityHashes: false,
+    },
+  } as unknown as NormalizedFederationConfig;
+}
+
+describe("resolveAngularLocaleData", () => {
+  it("returns null for built-in english locales", () => {
+    const root = makeFakeWorkspace(["de-CH"]);
+    expect(resolveAngularLocaleData("en", root)).toBeNull();
+    expect(resolveAngularLocaleData("en-US", root)).toBeNull();
+  });
+
+  it("resolves an exact match", () => {
+    const root = makeFakeWorkspace(["de-CH"], "22.0.0");
+    const result = resolveAngularLocaleData("de-CH", root);
+    expect(result).not.toBeNull();
+    expect(result!.packageName).toBe("@angular/common/locales/global/de-CH");
+    expect(result!.matchedCode).toBe("de-CH");
+    expect(result!.entryPoint).toBe(
+      "node_modules/@angular/common/locales/global/de-CH.js",
+    );
+    expect(result!.version).toBe("22.0.0");
+  });
+
+  it("falls back to a shorter locale tag when the exact code is missing", () => {
+    // Mirrors angular's i18n-locale-plugin behaviour: de-XYZ → de
+    const root = makeFakeWorkspace(["de"]);
+    const result = resolveAngularLocaleData("de-XYZ", root);
+    expect(result).not.toBeNull();
+    expect(result!.matchedCode).toBe("de");
+    expect(result!.packageName).toBe("@angular/common/locales/global/de");
+  });
+
+  it("returns null when the locale cannot be resolved at all", () => {
+    const root = makeFakeWorkspace([]);
+    expect(resolveAngularLocaleData("de-CH", root)).toBeNull();
+  });
+});
+
+describe("registerAngularLocaleDataInFederationConfig", () => {
+  it("does nothing when i18n is undefined", () => {
+    const root = makeFakeWorkspace(["de-CH"]);
+    const config = emptyConfig();
+    const registered = registerAngularLocaleDataInFederationConfig(
+      config,
+      undefined,
+      root,
+    );
+    expect(registered).toEqual([]);
+    expect(Object.keys(config.shared)).toEqual([]);
+  });
+
+  it("does nothing for a default en-US source locale", () => {
+    const root = makeFakeWorkspace(["de-CH"]);
+    const config = emptyConfig();
+    const i18n: I18nConfig = { sourceLocale: "en-US", locales: {} };
+    const registered = registerAngularLocaleDataInFederationConfig(
+      config,
+      i18n,
+      root,
+    );
+    expect(registered).toEqual([]);
+    expect(Object.keys(config.shared)).toEqual([]);
+  });
+
+  it("registers a shared entry for an object-form non-english sourceLocale", () => {
+    const root = makeFakeWorkspace(["de-CH"]);
+    const config = emptyConfig();
+    const i18n: I18nConfig = {
+      sourceLocale: { code: "de-CH", baseHref: "/de/" },
+      locales: {},
+    };
+
+    const registered = registerAngularLocaleDataInFederationConfig(
+      config,
+      i18n,
+      root,
+    );
+
+    expect(registered).toEqual(["@angular/common/locales/global/de-CH"]);
+    const entry = config.shared["@angular/common/locales/global/de-CH"];
+    expect(entry).toBeDefined();
+    expect(entry!.platform).toBe("browser");
+    expect(entry!.build).toBe("default");
+    expect(entry!.packageInfo?.entryPoint).toBe(
+      "node_modules/@angular/common/locales/global/de-CH.js",
+    );
+  });
+
+  it("also handles the string-form sourceLocale (regression: bug is not specific to object form)", () => {
+    const root = makeFakeWorkspace(["fr-CH"]);
+    const config = emptyConfig();
+    const i18n: I18nConfig = { sourceLocale: "fr-CH", locales: {} };
+
+    const registered = registerAngularLocaleDataInFederationConfig(
+      config,
+      i18n,
+      root,
+    );
+
+    expect(registered).toEqual(["@angular/common/locales/global/fr-CH"]);
+  });
+
+  it("registers inline locales requested via the dev-server locale filter", () => {
+    const root = makeFakeWorkspace(["de-CH", "fr-CH"]);
+    const config = emptyConfig();
+    const i18n: I18nConfig = {
+      sourceLocale: { code: "de-CH" },
+      locales: { "fr-CH": { translation: "messages.fr-CH.xlf" } },
+    };
+
+    const registered = registerAngularLocaleDataInFederationConfig(
+      config,
+      i18n,
+      root,
+      ["fr-CH"],
+    );
+
+    expect(new Set(registered)).toEqual(
+      new Set([
+        "@angular/common/locales/global/de-CH",
+        "@angular/common/locales/global/fr-CH",
+      ]),
+    );
+  });
+
+  it("does not overwrite an entry the user already configured", () => {
+    const root = makeFakeWorkspace(["de-CH"]);
+    const config = emptyConfig();
+    const userEntry = {
+      singleton: true,
+      strictVersion: true,
+      requiredVersion: "auto",
+      chunks: false,
+      platform: "browser" as const,
+      build: "default" as const,
+      packageInfo: {
+        entryPoint: "custom/path.js",
+        version: "0.0.0",
+        esm: true,
+      },
+    };
+    config.shared["@angular/common/locales/global/de-CH"] = userEntry;
+    const i18n: I18nConfig = {
+      sourceLocale: { code: "de-CH" },
+      locales: {},
+    };
+
+    const registered = registerAngularLocaleDataInFederationConfig(
+      config,
+      i18n,
+      root,
+    );
+
+    expect(registered).toEqual([]);
+    expect(config.shared["@angular/common/locales/global/de-CH"]).toBe(
+      userEntry,
+    );
+  });
+
+  it("warns and skips locales that cannot be resolved on disk but still processes the rest", () => {
+    const root = makeFakeWorkspace(["de-CH"]);
+    const config = emptyConfig();
+    const i18n: I18nConfig = {
+      sourceLocale: { code: "de-CH" },
+      locales: {},
+    };
+
+    const registered = registerAngularLocaleDataInFederationConfig(
+      config,
+      i18n,
+      root,
+      ["xx-YY"],
+    ); // xx-YY not present on disk
+
+    expect(registered).toEqual(["@angular/common/locales/global/de-CH"]);
+    expect(warnSpy).toHaveBeenCalledTimes(1);
+  });
+});