[I18n] Register translations before plugins init (#26078)

* Register translations before plugins init

* Fix i18n engine initialization

* Fix translationPath$ RxJS pipeline

* Move translations registration to mixin

* Fix arrays concatenation

* Use prettier

* Fix translations relative paths

* Use globby instead of glob

* Update docs

* Move globby to dependencies

* Get rid of translation directories config

* Update globby patterns

* Search only for current locale translation files

package.json

@@ -144,6 +144,7 @@
     "getos": "^3.1.0",
     "glob": "^7.1.2",
     "glob-all": "^3.1.0",
+    "globby": "^8.0.1",
     "good-squeeze": "2.1.0",
     "h2o2": "^8.1.2",
     "handlebars": "4.0.5",
@@ -337,7 +338,6 @@
     "fetch-mock": "^5.13.1",
     "geckodriver": "1.12.2",
     "getopts": "2.0.0",
-    "globby": "^8.0.1",
     "grunt": "1.0.1",
     "grunt-cli": "^1.2.0",
     "grunt-contrib-watch": "^1.1.0",

packages/kbn-i18n/README.md

@@ -33,21 +33,7 @@ For example:
 src/legacy/core_plugins/kibana/translations/fr.json
 ```
 
-When a new translation file is added, you have to register this file into
-`uiExports.translations` array of plugin constructor parameters. For example:
-```js
-export default function (kibana) {
-  return new kibana.Plugin({
-    uiExports: {
-      translations: [
-        resolve(__dirname, './translations/fr.json'),
-      ],
-      ...
-    },
-    ...
-  });
-}
-```
+The engine scans `x-pack/plugins/*/translations`, `src/core_plugins/*/translations`, `plugins/*/translations` and `src/ui/translations` folders on initialization, so there is no need to register translation files.
 
 The engine uses a `config/kibana.yml` file for locale resolution process. If locale is
 defined via `i18n.locale` option in `config/kibana.yml` then it will be used as a base

src/legacy/core_plugins/kibana/index.js

@@ -134,8 +134,6 @@ export default function (kibana) {
         };
       },
 
-      translations: [],
-
       mappings,
       uiSettingDefaults: getUiSettingDefaults(),
     },

src/legacy/core_plugins/timelion/index.js

@@ -104,7 +104,6 @@ export default function (kibana) {
           category: ['timelion'],
         }
       },
-      translations: [],
     },
     init: require('./init.js'),
   });

src/server/i18n/index.js

@@ -17,12 +17,45 @@
  * under the License.
  */
 
+import { resolve } from 'path';
+import globby from 'globby';
 import { i18n, i18nLoader } from '@kbn/i18n';
 
+import { fromRoot } from '../../utils';
+
 export async function i18nMixin(kbnServer, server, config) {
-  const { translationPaths = [] } = kbnServer.uiExports;
   const locale = config.get('i18n.locale');
 
+  const translationsDirs = [fromRoot('src/ui/translations')];
+
+  const groupedEntries = await Promise.all([
+    ...config.get('plugins.scanDirs').map(async path => {
+      const entries = await globby(`*/translations/${locale}.json`, {
+        cwd: path,
+      });
+      return entries.map(entry => resolve(path, entry));
+    }),
+
+    ...config.get('plugins.paths').map(async path => {
+      const entries = await globby(
+        [`translations/${locale}.json`, `plugins/*/translations/${locale}.json`],
+        {
+          cwd: path,
+        }
+      );
+      return entries.map(entry => resolve(path, entry));
+    }),
+
+    ...translationsDirs.map(async path => {
+      const entries = await globby(`${locale}.json`, {
+        cwd: path,
+      });
+      return entries.map(entry => resolve(path, entry));
+    }),
+  ]);
+
+  const translationPaths = [].concat(...groupedEntries);
+
   i18nLoader.registerTranslationFiles(translationPaths);
 
   const pureTranslations = await i18nLoader.getTranslationsByLocale(locale);

src/server/kbn_server.js

@@ -75,6 +75,9 @@ export default class KbnServer {
       // writes pid file
       pidMixin,
 
+      // scan translations dirs, register locale files, initialize i18n engine and define `server.getUiTranslations`
+      i18nMixin,
+
       // find plugins and set this.plugins and this.pluginSpecs
       Plugins.scanMixin,
 
@@ -83,7 +86,6 @@ export default class KbnServer {
 
       // setup this.uiExports and this.uiBundles
       uiMixin,
-      i18nMixin,
       indexPatternsMixin,
 
       // setup saved object routes

src/ui/ui_exports/ui_export_types/index.js

@@ -61,10 +61,6 @@ export {
   shareContextMenuExtensions,
 } from './ui_app_extensions';
 
-export {
-  translations,
-} from './ui_i18n';
-
 export {
   link,
   links,

src/ui/ui_exports/ui_export_types/ui_i18n.js

@@ -1,24 +0,0 @@
-/*
- * Licensed to Elasticsearch B.V. under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch B.V. licenses this file to you 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.
- */
-
-import { flatConcatAtType } from './reduce';
-import { wrap, alias } from './modify_reduce';
-
-// paths to translation files
-export const translations = wrap(alias('translationPaths'), flatConcatAtType);