Bug 1761835 - Add a test for switching locales and string bundles; r=platform-i18n-reviewers,dminor

Differential Revision: https://phabricator.services.mozilla.com/D144032

intl/locale/moz.build

@@ -6,8 +6,11 @@
 
 XPCSHELL_TESTS_MANIFESTS += ["tests/unit/xpcshell.ini"]
 
+BROWSER_CHROME_MANIFESTS += ["tests/browser/browser.ini"]
+
 TESTING_JS_MODULES += [
     "tests/LangPackMatcherTestUtils.jsm",
+    "tests/LangPackTestUtils.jsm",
 ]
 
 toolkit = CONFIG["MOZ_WIDGET_TOOLKIT"]

intl/locale/tests/LangPackTestUtils.jsm

@@ -0,0 +1,186 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+var EXPORTED_SYMBOLS = ["setupFakeLangpacks"];
+
+const { AddonTestUtils } = ChromeUtils.import(
+  "resource://testing-common/AddonTestUtils.jsm"
+);
+const { AppConstants } = ChromeUtils.import(
+  "resource://gre/modules/AppConstants.jsm"
+);
+const { OS } = ChromeUtils.import("resource://gre/modules/osfile.jsm");
+
+/**
+ * Allows the current app to install fake langpacks. This is useful for testing live
+ * language switching where the browser can switch languages without a restart, as well
+ * as testing novel message caching schemes.
+ *
+ * It's generally not recommended to assert against actual localized strings, as changing
+ * these will break tests, and lock in the test suite to a single language. However, with
+ * fake langpacks, the real strings can be tested against since they are defined in the
+ * fake langpack inside of the test.
+ *
+ * Usage:
+ *
+ *   add_task(async function test_stringBundleInvalidation() {
+ *     const fakeLangpacks = await setupFakeLangpacks(this, SpecialPowers);
+ *
+ *     await fakeLangpacks.install({
+ *       locale: "es-ES",
+ *       propertiesFiles: [
+ *         {
+ *           rootURL: "chrome://branding/locale",
+ *           files: {
+ *             "brand.properties": "brandFullName=Zorro de Fuego",
+ *             "test-only.properties": "testOnly=Mensaje solo para pruebas"
+ *           },
+ *         },
+ *       ],
+ *     });
+ *
+ *     Services.locale.requestedLocales = ["es-ES"];
+ *     const bundle1 = Services.strings.createBundle(
+ *      "chrome://branding/locale/branding.properties"
+ *     );
+ *     const bundle2 = Services.strings.createBundle(
+ *      "chrome://branding/locale/test-only.properties"
+ *     );
+ *   });
+ *
+ * @param {object} testEnv - The `this` object from the test.
+ * @param {SpecialPowers} SpecialPowers - Generally a property on `self` in the test.
+ *
+ * @return {Promise<{
+ *  install: (options: FakeLangpackOptions) => Promise<nsIFile>,
+ *  create: (options: FakeLangpackOptions) => Promise<nsIFile>,
+ * }>}
+ */
+async function setupFakeLangpacks(testEnv, SpecialPowers) {
+  /**
+   * Create a test-only langpack, with actual content.
+   *
+   * @param {FakeLangpackOptions} options
+   * @returns {Promise<nsIFile>}
+   */
+  function create(options) {
+    const { locale, propertiesFiles } = options;
+    const xpiFiles = {
+      "manifest.json": getManifestData(locale, propertiesFiles),
+    };
+    for (const { rootURL, files } of propertiesFiles || []) {
+      const slug = getChromeUrlSlug(rootURL);
+      const fakePath = getFakeXPIPath(slug);
+      for (const [name, contents] of Object.entries(files)) {
+        xpiFiles[OS.Path.join(fakePath, name)] = contents;
+      }
+    }
+    return AddonTestUtils.createTempXPIFile(xpiFiles);
+  }
+
+  /**
+   * Create and install a test-only langpack, with actual content. This XPI file will
+   * be created in a temp directory, and actually installed in the app.
+   *
+   * @param {FakeLangpackOptions} options
+   * @returns {Promise<nsIFile>}
+   */
+  function install(options) {
+    testEnv.info(`Installing the ${options.locale} langpack`);
+    return AddonTestUtils.promiseInstallFile(create(options));
+  }
+
+  AddonTestUtils.initMochitest(testEnv);
+
+  await SpecialPowers.pushPrefEnv({
+    set: [["extensions.langpacks.signatures.required", false]],
+  });
+
+  return {
+    install,
+    create,
+  };
+}
+
+/**
+ * Expect URLs to come in the form "chrome://slug/locale".
+ *
+ * @returns {string}
+ */
+function getChromeUrlSlug(url) {
+  const result = /^chrome:\/\/(\w+)\/locale\/?$/.exec(url);
+  if (!result) {
+    throw new Error(
+      'Expected the properties file\'s chrome URL to take the form: "chrome://slug/locale":' +
+        JSON.stringify(url)
+    );
+  }
+  return result[1];
+}
+
+function getManifestData(locale, propertiesFiles) {
+  const chrome_resources = {};
+  for (const { rootURL } of propertiesFiles) {
+    const slug = getChromeUrlSlug(rootURL);
+    chrome_resources[slug] = getFakeXPIPath(slug) + "/";
+  }
+  return {
+    langpack_id: locale,
+    name: `${locale} Language Pack`,
+    description: `${locale} Language pack`,
+    languages: {
+      [locale]: {
+        chrome_resources,
+        version: "1",
+      },
+    },
+    applications: {
+      gecko: {
+        strict_min_version: AppConstants.MOZ_APP_VERSION,
+        id: `langpack-${locale}@firefox.mozilla.org`,
+        strict_max_version: AppConstants.MOZ_APP_VERSION,
+      },
+    },
+    version: "2.0",
+    manifest_version: 2,
+    sources: {
+      browser: {
+        base_path: "browser/",
+      },
+    },
+    author: "Mozilla",
+  };
+}
+
+/**
+ * @typedef {object} FakeProperties
+ * @property {string} rootURL - The path that gets used for the chrome URL. It must take
+ *   the form "chrome://slug/locale".
+ * @property {{[string]: string}} files - The list of files that will be placed in the
+ *   XPI. The key is the file name, and the value is the contents of the file.
+ */
+
+/**
+ * @typedef {object} FakeLangpackOptions
+ * @property {string} locale - The BCP 47 identifier
+ * @property {FakeProperties[]} propertiesFiles - This list of fake properties files
+ *   to be served from chrome URLs. These can either be invented files, or shadow
+ *   the underlying translation files.
+ */
+
+/**
+ * The real paths in XPI files are something like:
+ *
+ * - browser/chrome/es-ES/locale/branding/brand.properties
+ * - browser/chrome/es-ES/locale/browser/browser.properties
+ * - browser/chrome/es-ES/locale/es-ES/devtools/client/debugger.properties
+ * - browser/features/formautofill@mozilla.org/es-ES/locale/es-ES/formautofill.properties
+ *
+ * However, in the manifest.json, the chrome URLs can point to arbitrary files via
+ * the chrome_resources key. This function generates an arbitrary fake path to store
+ * the files in.
+ */
+function getFakeXPIPath(rootSlug) {
+  return `fake-${rootSlug}`;
+}

intl/locale/tests/browser/browser.ini

@@ -0,0 +1,5 @@
+[DEFAULT]
+support-files =
+  head.js
+
+[browser_stringBundleInvalidation.js]

intl/locale/tests/browser/browser_stringBundleInvalidation.js

@@ -0,0 +1,104 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const { setupFakeLangpacks } = ChromeUtils.import(
+  "resource://testing-common/LangPackTestUtils.jsm"
+);
+
+add_task(async function test_stringBundleInvalidation() {
+  const fakeLangpacks = await setupFakeLangpacks(this, SpecialPowers);
+
+  await fakeLangpacks.install({
+    locale: "es-ES",
+    propertiesFiles: [
+      {
+        rootURL: "chrome://branding/locale",
+        files: {
+          // Localizers don't really translate the brand name this way, but it
+          // makes for a useful test.
+          "brand.properties": "brandFullName=Zorro de Fuego",
+          "test-only.properties": "testOnly=Mensaje solo para pruebas",
+        },
+      },
+    ],
+  });
+
+  await fakeLangpacks.install({
+    locale: "fr",
+    propertiesFiles: [
+      {
+        rootURL: "chrome://branding/locale",
+        files: {
+          // Localizers don't really translate the brand name this way, but it
+          // makes for a useful test.
+          "brand.properties": "brandFullName=Renard de Feu",
+          "test-only.properties": "testOnly=Message de test uniquement",
+        },
+      },
+    ],
+  });
+
+  info(`Creating the bundle "chrome://branding/locale/brand.properties"`);
+  const sharedStringBundle = Services.strings.createBundle(
+    "chrome://branding/locale/brand.properties"
+  );
+
+  // Don't write an assertion directly off of the brand name, as it could change
+  // depending on the build.
+  const brandFullName = sharedStringBundle.GetStringFromName("brandFullName");
+  info("Reading the brand name: " + brandFullName);
+  Assert.equal(typeof brandFullName, "string");
+  Assert.greater(brandFullName.length, 0);
+
+  info("Changing the locale to es-ES.");
+  Services.locale.requestedLocales = ["es-ES"];
+  await document.l10n.ready;
+
+  info("Creating the test-only.properties bundle in Spanish.");
+  const testOnlyBundle = Services.strings.createBundle(
+    "chrome://branding/locale/test-only.properties"
+  );
+
+  Assert.equal(
+    testOnlyBundle.GetStringFromName("testOnly"),
+    "Mensaje solo para pruebas",
+    "String bundles can load the new locale."
+  );
+
+  Assert.equal(
+    sharedStringBundle.GetStringFromName("brandFullName"),
+    brandFullName,
+    "Shared string bundles are not invalidated."
+  );
+
+  info("Changing the locale to fr.");
+  Services.locale.requestedLocales = ["fr"];
+  await document.l10n.ready;
+
+  Assert.equal(
+    sharedStringBundle.GetStringFromName("brandFullName"),
+    brandFullName,
+    "Shared string bundles are not invalidated."
+  );
+  Assert.equal(
+    testOnlyBundle.GetStringFromName("testOnly"),
+    "Mensaje solo para pruebas",
+    "Existing string bundles are retained."
+  );
+
+  Assert.equal(
+    Services.strings
+      .createBundle("chrome://branding/locale/brand.properties")
+      .GetStringFromName("brandFullName"),
+    brandFullName,
+    "Shared string bundles are not invalidated."
+  );
+  Assert.equal(
+    Services.strings
+      .createBundle("chrome://branding/locale/test-only.properties")
+      .GetStringFromName("testOnly"),
+    "Message de test uniquement",
+    "The string bundle can be recreated."
+  );
+});