Adding german language to angular.json. Also adding test to catch these errors in the future fixes #428

angular.json

@@ -19,6 +19,10 @@
             "baseHref": "",
             "translation": "src/frontend/translate/messages.cn.xlf"
           },
+          "de": {
+            "baseHref": "",
+            "translation": "src/frontend/translate/messages.de.xlf"
+          },
           "es": {
             "baseHref": "",
             "translation": "src/frontend/translate/messages.es.xlf"

test/frontend/mocha.opts

@@ -0,0 +1 @@
+--recursive

test/frontend/translation.spec.ts

@@ -0,0 +1,37 @@
+import {ProjectPath} from '../../src/backend/ProjectPath';
+import {promises as fsp} from 'fs';
+const chai = require('chai');
+import path = require('path');
+const {expect} = chai;
+
+// to help WebStorm to handle the test cases
+declare let describe: any;
+
+
+describe('UI', () => {
+
+
+  it('translation should be listed in the angular.json', async () => {
+    const base = path.join('src', 'frontend', 'translate');
+    const translations = await fsp.readdir(path.join(ProjectPath.Root, base));
+    const angularConfig = require(path.join(ProjectPath.Root, 'angular.json'));
+    const knownTranslations = angularConfig.projects.pigallery2.i18n.locales;
+
+
+    for (const t of translations) {
+      const lang = t.substr(t.indexOf('.') + 1, 2);
+      if (lang === 'en') {
+        continue; // no need to add 'en' as it is the default language.
+      }
+      const translationPath = path.join(base, t).replace(new RegExp('\\\\', 'g'), '/');
+      expect(knownTranslations[lang]).to.deep.equal({
+        baseHref: '',
+        translation: translationPath
+      }, translationPath + ' should be added to angular.json');
+    }
+
+
+  });
+
+
+});