Implement serializers (#19)

* Use serializers to generate JSON responses

* Add new files to cleanup script

Author: talyssonoc

scripts/cleanup.js

@@ -28,10 +28,12 @@ const tasks = new Listr([
         from: [
           /\s*const \{(\n.*)+.*app\/user'\);/,
           /\s*const.*UsersRepository'\);/,
+          /\s*const.*UserSerializer'\);/,
           /\, User: UserModel/,
           /\s*usersRepository.*\}\]/,
           /\,\s*UserModel/,
           /\s+createUser(.|\n)+.*DeleteUser\n/,
+          /\s+userSerializer: UserSerializer\n/
         ],
         to: ''
       });
@@ -44,10 +46,10 @@ const tasks = new Listr([
         path.join(srcAndTestPath, 'app', 'user', '**'),
         path.join(srcAndTestPath, 'domain', 'user', '**'),
         path.join(srcAndTestPath, 'infra', 'user', '**'),
+        path.join(srcAndTestPath, 'interfaces', 'http', 'user', '**'),
         path.join(srcPath, 'infra', 'database', 'migrate', '*.js'),
         path.join(srcPath, 'infra', 'database', 'seeds', '*.js'),
         path.join(srcPath, 'infra', 'database', 'models', 'User.js'),
-        path.join(srcPath, 'interfaces', 'http', 'user', '**'),
         path.join(testPath, 'features', 'api', 'users', '**'),
         path.join(testPath, 'support', 'factories', '*.js')
       ]);

src/container.js

@@ -11,6 +11,8 @@ const {
   DeleteUser
 } = require('./app/user');
 
+const UserSerializer = require('./interfaces/http/user/UserSerializer');
+
 const Server = require('./interfaces/http/Server');
 const router = require('./interfaces/http/router');
 const loggerMiddleware = require('./interfaces/http/logging/loggerMiddleware');
@@ -65,4 +67,9 @@ container.registerClass({
   deleteUser: DeleteUser
 });
 
+// Serializers
+container.registerValue({
+  userSerializer: UserSerializer
+});
+
 module.exports = container;

src/interfaces/http/user/UserSerializer.js

@@ -0,0 +1,10 @@
+const UserSerializer = {
+  serialize({ id, name }) {
+    return {
+      id,
+      name
+    };
+  }
+};
+
+module.exports = UserSerializer;

src/interfaces/http/user/UsersController.js

@@ -6,6 +6,8 @@ const UsersController = {
   get router() {
     const router = Router();
 
+    router.use(inject('userSerializer'));
+
     router.get('/', inject('getAllUsers'), this.index);
     router.get('/:id', inject('getUser'), this.show);
     router.post('/', inject('createUser'), this.create);
@@ -16,26 +18,30 @@ const UsersController = {
   },
 
   index(req, res, next) {
-    const { getAllUsers } = req;
+    const { getAllUsers, userSerializer } = req;
     const { SUCCESS, ERROR } = getAllUsers.outputs;
 
     getAllUsers
       .on(SUCCESS, (users) => {
-        res.status(Status.OK).json(users);
+        res
+          .status(Status.OK)
+          .json(users.map(userSerializer.serialize));
       })
       .on(ERROR, next);
 
     getAllUsers.execute();
   },
 
   show(req, res, next) {
-    const { getUser } = req;
+    const { getUser, userSerializer } = req;
 
     const { SUCCESS, ERROR, NOT_FOUND } = getUser.outputs;
 
     getUser
       .on(SUCCESS, (user) => {
-        res.status(Status.OK).json(user);
+        res
+          .status(Status.OK)
+          .json(userSerializer.serialize(user));
       })
       .on(NOT_FOUND, (error) => {
         res.status(Status.NOT_FOUND).json({
@@ -49,12 +55,14 @@ const UsersController = {
   },
 
   create(req, res, next) {
-    const { createUser } = req;
+    const { createUser, userSerializer } = req;
     const { SUCCESS, ERROR, VALIDATION_ERROR } = createUser.outputs;
 
     createUser
       .on(SUCCESS, (user) => {
-        res.status(Status.CREATED).json(user);
+        res
+          .status(Status.CREATED)
+          .json(userSerializer.serialize(user));
       })
       .on(VALIDATION_ERROR, (error) => {
         res.status(Status.BAD_REQUEST).json({
@@ -68,12 +76,14 @@ const UsersController = {
   },
 
   update(req, res, next) {
-    const { updateUser } = req;
+    const { updateUser, userSerializer } = req;
     const { SUCCESS, ERROR, VALIDATION_ERROR, NOT_FOUND } = updateUser.outputs;
 
     updateUser
       .on(SUCCESS, (user) => {
-        res.status(Status.ACCEPTED).json(user);
+        res
+          .status(Status.ACCEPTED)
+          .json(userSerializer.serialize(user));
       })
       .on(VALIDATION_ERROR, (error) => {
         res.status(Status.BAD_REQUEST).json({

test/unit/interfaces/http/user/UserSerializer.spec.js

@@ -0,0 +1,40 @@
+const { expect } = require('chai');
+const UserSerializer = require('src/interfaces/http/user/UserSerializer');
+const User = require('src/domain/user/User');
+
+describe('Interfaces :: HTTP :: User :: UserSerializer', () => {
+  it('returns id and name', () => {
+    const serializedUser = UserSerializer.serialize({
+      id: 123,
+      name: 'The User'
+    });
+
+    expect(serializedUser).to.eql({
+      id: 123,
+      name: 'The User'
+    });
+  });
+
+  it('ignores extra attributes', () => {
+    const serializedUser = UserSerializer.serialize({
+      id: 321,
+      name: 'The User',
+      unknown: 'Hello!'
+    });
+
+    expect(serializedUser).to.eql({
+      id: 321,
+      name: 'The User'
+    });
+  });
+
+  it('is able to serialize user entity instances', () => {
+    const user = new User({ id: 1, name: 'User :)' });
+    const serializedUser = UserSerializer.serialize(user);
+
+    expect(serializedUser).to.eql({
+      id: 1,
+      name: 'User :)'
+    });
+  });
+});