profile: store preferred language in the database

src/routes/profile.js

@@ -8,6 +8,7 @@ exports = module.exports = {
     setFallbackEmail,
     getAvatar,
     setAvatar,
+    setLanguage,
     getBackgroundImage,
     setBackgroundImage,
     setPassword,
@@ -65,6 +66,7 @@ async function get(req, res, next) {
         role: req.user.role,
         source: req.user.source,
         hasBackgroundImage: !!backgroundImage,
+        language: req.user.language,
         avatarUrl: `https://${dashboardFqdn}/api/v1/profile/avatar/${req.user.id}`,
         avatarType: avatarType.toString() // this is a Buffer
     }));
@@ -106,6 +108,18 @@ async function setDisplayName(req, res, next) {
     next(new HttpSuccess(204));
 }
 
+async function setLanguage(req, res, next) {
+    assert.strictEqual(typeof req.user, 'object');
+    assert.strictEqual(typeof req.body, 'object');
+
+    if ('language' in req.body && typeof req.body.language !== 'string') return next(new HttpError(400, 'language must be string'));
+
+    const [error] = await safe(users.update(req.user, { language: req.body.language }, AuditSource.fromRequest(req)));
+    if (error) return next(BoxError.toHttpError(error));
+
+    next(new HttpSuccess(204));
+}
+
 async function setAvatar(req, res, next) {
     assert.strictEqual(typeof req.user, 'object');