added new endpoint

src/controllers/user.js

@@ -66,6 +66,14 @@ class UserController {
 
         return res.status(200).send(result);
     }
+
+    async getById(req, res) {
+        const userId = req.params.userId
+
+        let result = (await UserService.getById(userId)).username;
+
+        return res.status(200).send(result);
+    }
 }
 
 export default new UserController()

src/routers/user.js

@@ -11,5 +11,7 @@ UserRouter.get('/synchronize/:groupId', tryHandler(auth.authenticate), tryHandle
 UserRouter.post('/changeUsername', tryHandler(auth.authenticate), tryHandler(auth.requireUsername), tryHandler(UserController.changeUsername));
 UserRouter.post('/changePassword', tryHandler(auth.authenticate), tryHandler(auth.requirePassword), tryHandler(UserController.changePassword));
 UserRouter.get('/myGroups', tryHandler(auth.authenticate), tryHandler(UserController.getAllGroupsForUser));
+//Maybe I should add a middleware like "auth.usersShareGroups" 
+UserRouter.get('/byId/:userId', tryHandler(auth.authenticate), tryHandler(UserController.getById))
 
 export default UserRouter;

src/services/user.js

@@ -43,6 +43,12 @@ class UserService {
     async getAllGroupsForUser(userId) {
         return (await db.query("SELECT groups FROM users WHERE id = $1", [userId])).rows[0].groups
     }
+
+    async getById(userId) {
+        let res = (await db.query("SELECT * FROM users WHERE id = $1", [userId]))
+        if (res.rowCount == 0) throw new customError(`getById no user found`, responseCodes.responses.user.not_found)
+        return res.rows[0]
+    }
 }
 
 export default new UserService();