i18n: introduce script to swap in new locale to LHR

lighthouse-core/lib/i18n/i18n.js

@@ -259,6 +259,20 @@ function getFormatted(icuMessageIdOrRawString, locale) {
   return icuMessageIdOrRawString;
 }
 
+/**
+ * @param {LH.Locale} locale
+ * @param {string} icuMessageId
+ * @param {*} [values]
+ * @return {string}
+ */
+function formatMessageFromIdWithValues(locale, icuMessageId, values) {
+  const icuMessageIdRegex = /(.* \| .*)$/;
+  if (!icuMessageIdRegex.test(icuMessageId)) throw new Error('This is not an ICU message ID');
+
+  const {formattedString} = _formatIcuMessage(locale, icuMessageId, '', values);
+  return formattedString;
+}
+
 /**
  * @param {string} icuMessageInstanceId
  * @param {LH.Locale} locale
@@ -331,6 +345,7 @@ module.exports = {
   getRendererFormattedStrings,
   createMessageInstanceIdFn,
   getFormatted,
+  formatMessageFromIdWithValues,
   replaceIcuMessageInstanceIds,
   isIcuMessage,
 };

lighthouse-core/lib/i18n/swap-locale.js

@@ -0,0 +1,44 @@
+/**
+ * @license Copyright 2019 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
+ */
+'use strict';
+
+/* eslint-disable no-console, max-len */
+
+const _set = require('lodash.set');
+
+const i18n = require('./i18n.js');
+
+/**
+ * Replaces all strings within an LHR with ones from a different locale
+ * @param {LH.Result} lhr
+ * @param {LH.Locale} requestedLocale
+ * @return {LH.Result}
+ */
+function swapLocale(lhr, requestedLocale) {
+  // copy LHR to avoid mutating provided LHR
+  lhr = JSON.parse(JSON.stringify(lhr));
+
+  const locale = i18n.lookupLocale(requestedLocale);
+  const {icuMessagePaths} = lhr.i18n;
+
+  Object.entries(icuMessagePaths).forEach(([icuMessageId, messageInstancesInLHR]) => {
+    for (const instance of messageInstancesInLHR) {
+      // The path that _formatPathAsString() generated
+      const path = /** @type {LH.I18NMessageValuesEntry} */ (instance).path || /** @type {string} */ (instance);
+      const values = /** @type {LH.I18NMessageValuesEntry} */ (instance).values || undefined;
+      // Get new formatted strings in revised locale
+      const formattedStr = i18n.formatMessageFromIdWithValues(locale, icuMessageId, values);
+      // Write string back into the LHR
+      _set(lhr, path, formattedStr);
+    }
+  });
+
+  // Tweak the config locale
+  lhr.configSettings.locale = locale;
+  return lhr;
+}
+
+module.exports = swapLocale;

lighthouse-core/test/lib/i18n/swap-locale-test.js

@@ -0,0 +1,28 @@
+/**
+ * @license Copyright 2018 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
+ */
+'use strict';
+
+const swapLocale = require('../../../lib/i18n/swap-locale.js');
+
+const lhr = require('../../results/sample_v2.json');
+
+/* eslint-env jest */
+
+describe('swap-locale', () => {
+  it('can change golden LHR english strings into spanish', () => {
+    const lhrEn = /** @type {LH.Result} */ (JSON.parse(JSON.stringify(lhr)));
+
+    expect(lhrEn.audits.plugins.title).toEqual('Document avoids plugins');
+    expect(lhrEn.audits['dom-size'].displayValue).toEqual('31 elements');
+
+    const lhrEs = swapLocale(lhrEn, 'es');
+
+    // Basic replacement
+    expect(lhrEs.audits.plugins.title).toEqual('El documento no usa complementos');
+    // With ICU string argument values
+    expect(lhrEs.audits['dom-size'].displayValue).toEqual('31 nodos');
+  });
+});

package.json

@@ -81,6 +81,7 @@
     "@types/jest": "^24.0.9",
     "@types/jpeg-js": "^0.3.0",
     "@types/lodash.isequal": "^4.5.2",
+    "@types/lodash.set": "^4.3.6",
     "@types/make-dir": "^1.0.3",
     "@types/node": "*",
     "@types/opn": "^3.0.28",
@@ -117,6 +118,7 @@
     "isomorphic-fetch": "^2.2.1",
     "jest": "^24.3.0",
     "jsdom": "^12.2.0",
+    "lodash.set": "^4.3.2",
     "make-dir": "^1.3.0",
     "npm-run-posix-or-windows": "^2.0.2",
     "nyc": "^13.3.0",

types/lhr.d.ts

@@ -8,7 +8,8 @@ import LHError = require('../lighthouse-core/lib/lh-error.js');
 
 declare global {
   module LH {
-    export type I18NMessageEntry = string | {path: string, values: any};
+    export type I18NMessageValuesEntry = {path: string, values: any};
+    export type I18NMessageEntry = string | I18NMessageValuesEntry;
 
     export interface I18NMessages {
       [icuMessageId: string]: I18NMessageEntry[];

yarn.lock

@@ -533,6 +533,13 @@
   dependencies:
     "@types/lodash" "*"
 
+"@types/lodash.set@^4.3.6":
+  version "4.3.6"
+  resolved "https://registry.yarnpkg.com/@types/lodash.set/-/lodash.set-4.3.6.tgz#33e635c2323f855359225df6a5c8c6f1f1908264"
+  integrity sha512-ZeGDDlnRYTvS31Laij0RsSaguIUSBTYIlJFKL3vm3T2OAZAQj2YpSvVWJc0WiG4jqg9fGX6PAPGvDqBcHfSgFg==
+  dependencies:
+    "@types/lodash" "*"
+
 "@types/lodash@*":
   version "4.14.106"
   resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.106.tgz#6093e9a02aa567ddecfe9afadca89e53e5dce4dd"
@@ -5587,6 +5594,11 @@ lodash.memoize@~3.0.3:
   resolved "https://registry.yarnpkg.com/lodash.memoize/-/lodash.memoize-3.0.4.tgz#2dcbd2c287cbc0a55cc42328bd0c736150d53e3f"
   integrity sha1-LcvSwofLwKVcxCMovQxzYVDVPj8=
 
+lodash.set@^4.3.2:
+  version "4.3.2"
+  resolved "https://registry.yarnpkg.com/lodash.set/-/lodash.set-4.3.2.tgz#d8757b1da807dde24816b0d6a84bea1a76230b23"
+  integrity sha1-2HV7HagH3eJIFrDWqEvqGnYjCyM=
+
 lodash.sortby@^4.7.0:
   version "4.7.0"
   resolved "https://registry.yarnpkg.com/lodash.sortby/-/lodash.sortby-4.7.0.tgz#edd14c824e2cc9c1e0b0a1b42bb5210516a42438"