Fix translation download and add empty languages (#5824)

build-scripts/gulp/download_translations.js

@@ -1,9 +1,14 @@
 const del = require("del");
 const gulp = require("gulp");
+const fs = require("fs");
 const mapStream = require("map-stream");
 
-const inDir = "translations/frontend";
-const downloadDir = inDir + "/downloads";
+const inDirFrontend = "translations/frontend";
+const inDirBackend = "translations/backend";
+const downloadDir = "translations/downloads";
+const srcMeta = "src/translations/translationMetadata.json";
+
+const encoding = "utf8";
 
 const tasks = [];
 
@@ -53,9 +58,25 @@ gulp.task(taskName, function () {
 });
 tasks.push(taskName);
 
+taskName = "check-all-files-exist";
+gulp.task(taskName, function () {
+  const file = fs.readFileSync(srcMeta, { encoding });
+  const meta = JSON.parse(file);
+  Object.keys(meta).forEach((lang) => {
+    if (!fs.existsSync(`${inDirFrontend}/${lang}.json`)) {
+      fs.writeFileSync(`${inDirFrontend}/${lang}.json`, JSON.stringify({}));
+    }
+    if (!fs.existsSync(`${inDirBackend}/${lang}.json`)) {
+      fs.writeFileSync(`${inDirBackend}/${lang}.json`, JSON.stringify({}));
+    }
+  });
+  return Promise.resolve();
+});
+tasks.push(taskName);
+
 taskName = "move-downloaded-translations";
 gulp.task(taskName, function () {
-  return gulp.src(`${downloadDir}/*.json`).pipe(gulp.dest(inDir));
+  return gulp.src(`${downloadDir}/*.json`).pipe(gulp.dest(inDirFrontend));
 });
 tasks.push(taskName);
 
@@ -65,6 +86,7 @@ gulp.task(
   gulp.series(
     "check-translations-html",
     "move-downloaded-translations",
+    "check-all-files-exist",
     "clean-downloaded-translations"
   )
 );