Use async/await (#9)

* Update Chai to accept async functions as expect parameter

* Use async/await instead of then/catch along the app

* Set Node version to allow async/await

Author: talyssonoc

.nvmrc

@@ -1 +1 @@
-6.0.0
+7.0.0

package.json

@@ -5,7 +5,7 @@
   "main": "index.js",
   "private": true,
   "engines": {
-    "node": ">=6.0.0"
+    "node": ">=7.0.0"
   },
   "scripts": {
     "start": "node cluster.js",
@@ -44,10 +44,10 @@
     "structure": "^1.2.0"
   },
   "devDependencies": {
-    "chai": "^3.5.0",
+    "chai": "^4.1.2",
     "chai-change": "^2.1.2",
     "chance": "^1.0.6",
-    "dirty-chai": "^1.2.2",
+    "dirty-chai": "^2.0.1",
     "eslint": "^3.17.1",
     "factory-girl": "^4.0.0",
     "istanbul": "^0.4.5",

src/app/Application.js

@@ -9,10 +9,12 @@ class Application {
     }
   }
 
-  start() {
-    return Promise.resolve()
-      .then(() => this.database && this.database.authenticate())
-      .then(() => this.server.start());
+  async start() {
+    if(this.database) {
+      await this.database.authenticate();
+    }
+
+    await this.server.start();
   }
 }
 

src/app/user/CreateUser.js

@@ -7,23 +7,22 @@ class CreateUser extends Operation {
     this.usersRepository = usersRepository;
   }
 
-  execute(userData) {
+  async execute(userData) {
     const { SUCCESS, ERROR, VALIDATION_ERROR } = this.outputs;
 
     const user = new User(userData);
 
-    this.usersRepository
-      .add(user)
-      .then((newUser) => {
-        this.emit(SUCCESS, newUser);
-      })
-      .catch((error) => {
-        if(error.message === 'ValidationError') {
-          return this.emit(VALIDATION_ERROR, error);
-        }
-
-        this.emit(ERROR, error);
-      });
+    try {
+      const newUser = await this.usersRepository.add(user);
+
+      this.emit(SUCCESS, newUser);
+    } catch(error) {
+      if(error.message === 'ValidationError') {
+        return this.emit(VALIDATION_ERROR, error);
+      }
+
+      this.emit(ERROR, error);
+    }
   }
 }
 

src/app/user/GetAllUsers.js

@@ -6,19 +6,18 @@ class GetAllUsers extends Operation {
     this.usersRepository = usersRepository;
   }
 
-  execute() {
+  async execute() {
     const { SUCCESS, ERROR } = this.outputs;
 
-    this.usersRepository
-      .getAll({
+    try {
+      const users = await this.usersRepository.getAll({
         attributes: ['id', 'name']
-      })
-      .then((users) => {
-        this.emit(SUCCESS, users);
-      })
-      .catch((error) => {
-        this.emit(ERROR, error);
       });
+
+      this.emit(SUCCESS, users);
+    } catch(error) {
+      this.emit(ERROR, error);
+    }
   }
 }
 

src/infra/user/SequelizeUsersRepository.js

@@ -5,29 +5,28 @@ class SequelizeUsersRepository {
     this.UserModel = UserModel;
   }
 
-  getAll(...args) {
-    return this.UserModel
-      .findAll(...args)
-      .then((users) => users.map(UserMapper.toEntity));
+  async getAll(...args) {
+    const users = await this.UserModel.findAll(...args);
+
+    return users.map(UserMapper.toEntity);
   }
 
-  add(user) {
+  async add(user) {
     const { valid, errors } = user.validate();
 
     if(!valid) {
       const error = new Error('ValidationError');
       error.details = errors;
 
-      return Promise.reject(error);
+      throw error;
     }
 
-    return this.UserModel
-      .create(UserMapper.toDatabase(user))
-      .then(UserMapper.toEntity);
+    const newUser = await this.UserModel.create(UserMapper.toDatabase(user));
+    return UserMapper.toEntity(newUser);
   }
 
-  count() {
-    return this.UserModel.count();
+  async count() {
+    return await this.UserModel.count();
   }
 }
 

test/api/users/createUser.spec.js

@@ -3,31 +3,29 @@ const { expect } = require('chai');
 
 describe('API :: POST /api/users', () => {
   context('when sent data is ok', () => {
-    it('creates and returns 200 and the new user', () => {
-      return request()
+    it('creates and returns 200 and the new user', async () => {
+      const { body } = await request()
         .post('/api/users')
         .send({
           name: 'New User'
         })
-        .expect(201)
-        .then(({ body }) => {
-          expect(body.id).to.exist;
-          expect(body.name).to.equal('New User');
-          expect(body).to.have.all.keys('id', 'name');
-        });
+        .expect(201);
+
+      expect(body.id).to.exist;
+      expect(body.name).to.equal('New User');
+      expect(body).to.have.all.keys('id', 'name');
     });
   });
 
   context('when name is missing', () => {
-    it('does not create and returns 400 with the validation error', () => {
-      return request()
+    it('does not create and returns 400 with the validation error', async () => {
+      const { body } = await request()
         .post('/api/users')
-        .expect(400)
-        .then(({ body }) => {
-          expect(body.type).to.equal('ValidationError');
-          expect(body.details).to.have.lengthOf(1);
-          expect(body.details[0].message).to.equal('"name" is required');
-        });
+        .expect(400);
+
+      expect(body.type).to.equal('ValidationError');
+      expect(body.details).to.have.lengthOf(1);
+      expect(body.details[0].message).to.equal('"name" is required');
     });
   });
 });

test/api/users/listUsers.spec.js

@@ -11,28 +11,28 @@ describe('API :: GET /api/users', () => {
       ]);
     });
 
-    it('return success with array of users', () => {
-      return request().get('/api/users')
-        .expect(200)
-        .then(({ body }) => {
-          expect(body).to.have.lengthOf(2);
+    it('return success with array of users', async () => {
+      const { body } = await request()
+        .get('/api/users')
+        .expect(200);
 
-          expect(body[0].name).to.equal('First');
-          expect(body[0]).to.have.all.keys('id', 'name');
+      expect(body).to.have.lengthOf(2);
 
-          expect(body[1].name).to.equal('Second');
-          expect(body[1]).to.have.all.keys('id', 'name');
-        });
+      expect(body[0].name).to.equal('First');
+      expect(body[0]).to.have.all.keys('id', 'name');
+
+      expect(body[1].name).to.equal('Second');
+      expect(body[1]).to.have.all.keys('id', 'name');
     });
   });
 
   context('when there are no users', () => {
-    it('return success with empty array', () => {
-      return request().get('/api/users')
-        .expect(200)
-        .then(({ body }) => {
-          expect(body).to.have.lengthOf(0);
-        });
+    it('return success with empty array', async () => {
+      const { body } = await request()
+        .get('/api/users')
+        .expect(200);
+
+      expect(body).to.have.lengthOf(0);
     });
   });
 });

test/infra/user/SequelizeUsersRepository.spec.js

@@ -13,19 +13,18 @@ describe('Infra :: User :: SequelizeUsersRepository', () => {
       ]);
     });
 
-    it('returns all users from the database', () => {
+    it('returns all users from the database', async () => {
       const repository = new SequelizeUsersRepository({ UserModel });
 
-      return repository.getAll()
-        .then((users) => {
-          expect(users).to.have.lengthOf(2);
+      const users = await repository.getAll();
 
-          expect(users[0]).to.be.instanceOf(User);
-          expect(users[0].name).to.equal('User 1');
+      expect(users).to.have.lengthOf(2);
 
-          expect(users[1]).to.be.instanceOf(User);
-          expect(users[1].name).to.equal('User 2');
-        });
+      expect(users[0]).to.be.instanceOf(User);
+      expect(users[0].name).to.equal('User 1');
+
+      expect(users[1]).to.be.instanceOf(User);
+      expect(users[1].name).to.equal('User 2');
     });
   });
 
@@ -40,12 +39,11 @@ describe('Infra :: User :: SequelizeUsersRepository', () => {
 
         expect(user.validate().valid).to.be.ok();
 
-        return expect(() => {
-          return repo.add(user)
-            .then((persistedUser) => {
-              expect(persistedUser.id).to.exist;
-              expect(persistedUser.name).to.equal('The User');
-            });
+        return expect(async () => {
+          const persistedUser = await repo.add(user);
+
+          expect(persistedUser.id).to.exist;
+          expect(persistedUser.name).to.equal('The User');
         }).to.alter(() => repo.count(), { by: 1 });
       });
     });

yarn.lock

@@ -382,13 +382,16 @@ chai-change@^2.1.2:
   version "2.1.2"
   resolved "https://registry.yarnpkg.com/chai-change/-/chai-change-2.1.2.tgz#1231cdf8bf5930eea1fab72b5cc4864e5bcae7f6"
 
-chai@^3.5.0:
-  version "3.5.0"
-  resolved "https://registry.yarnpkg.com/chai/-/chai-3.5.0.tgz#4d02637b067fe958bdbfdd3a40ec56fef7373247"
+chai@^4.1.2:
+  version "4.1.2"
+  resolved "https://registry.yarnpkg.com/chai/-/chai-4.1.2.tgz#0f64584ba642f0f2ace2806279f4f06ca23ad73c"
   dependencies:
     assertion-error "^1.0.1"
-    deep-eql "^0.1.3"
-    type-detect "^1.0.0"
+    check-error "^1.0.1"
+    deep-eql "^3.0.0"
+    get-func-name "^2.0.0"
+    pathval "^1.0.0"
+    type-detect "^4.0.0"
 
 chalk@^1.0.0, chalk@^1.1, chalk@^1.1.0, chalk@^1.1.1, chalk@^1.1.3:
   version "1.1.3"
@@ -408,6 +411,10 @@ charm@~0.1.1:
   version "0.1.2"
   resolved "https://registry.yarnpkg.com/charm/-/charm-0.1.2.tgz#06c21eed1a1b06aeb67553cdc53e23274bac2296"
 
+check-error@^1.0.1:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/check-error/-/check-error-1.0.2.tgz#574d312edd88bb5dd8912e9286dd6c0aed4aac82"
+
 chokidar@^1.4.3, chokidar@^1.6.1:
   version "1.6.1"
   resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-1.6.1.tgz#2f4447ab5e96e50fb3d789fd90d4c72e0e4c70c2"
@@ -702,11 +709,11 @@ decamelize@^1.0.0, decamelize@^1.1.1:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/decamelize/-/decamelize-1.2.0.tgz#f6534d15148269b20352e7bee26f501f9a191290"
 
-deep-eql@^0.1.3:
-  version "0.1.3"
-  resolved "https://registry.yarnpkg.com/deep-eql/-/deep-eql-0.1.3.tgz#ef558acab8de25206cd713906d74e56930eb69f2"
+deep-eql@^3.0.0:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/deep-eql/-/deep-eql-3.0.1.tgz#dfc9404400ad1c8fe023e7da1df1c147c4b444df"
   dependencies:
-    type-detect "0.1.1"
+    type-detect "^4.0.0"
 
 deep-extend@~0.4.0:
   version "0.4.1"
@@ -764,9 +771,9 @@ diff@1.4.0:
   version "1.4.0"
   resolved "https://registry.yarnpkg.com/diff/-/diff-1.4.0.tgz#7f28d2eb9ee7b15a97efd89ce63dcfdaa3ccbabf"
 
-dirty-chai@^1.2.2:
-  version "1.2.2"
-  resolved "https://registry.yarnpkg.com/dirty-chai/-/dirty-chai-1.2.2.tgz#78495e619635f7fe44219aa4c837849bf183142e"
+dirty-chai@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/dirty-chai/-/dirty-chai-2.0.1.tgz#6b2162ef17f7943589da840abc96e75bda01aff3"
 
 doctrine@^1.2.2:
   version "1.5.0"
@@ -1419,6 +1426,10 @@ get-caller-file@^1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/get-caller-file/-/get-caller-file-1.0.2.tgz#f702e63127e7e231c160a80c1554acb70d5047e5"
 
+get-func-name@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/get-func-name/-/get-func-name-2.0.0.tgz#ead774abee72e20409433a066366023dd6887a41"
+
 getpass@^0.1.1:
   version "0.1.6"
   resolved "https://registry.yarnpkg.com/getpass/-/getpass-0.1.6.tgz#283ffd9fc1256840875311c1b60e8c40187110e6"
@@ -2953,6 +2964,10 @@ path-type@^1.0.0:
     pify "^2.0.0"
     pinkie-promise "^2.0.0"
 
+pathval@^1.0.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/pathval/-/pathval-1.1.0.tgz#b942e6d4bde653005ef6b71361def8727d0645e0"
+
 pause-stream@0.0.11:
   version "0.0.11"
   resolved "https://registry.yarnpkg.com/pause-stream/-/pause-stream-0.0.11.tgz#fe5a34b0cbce12b5aa6a2b403ee2e73b602f1445"
@@ -3969,13 +3984,9 @@ type-check@~0.3.2:
   dependencies:
     prelude-ls "~1.1.2"
 
-type-detect@0.1.1:
-  version "0.1.1"
-  resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-0.1.1.tgz#0ba5ec2a885640e470ea4e8505971900dac58822"
-
-type-detect@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-1.0.0.tgz#762217cc06db258ec48908a1298e8b95121e8ea2"
+type-detect@^4.0.0:
+  version "4.0.3"
+  resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-4.0.3.tgz#0e3f2670b44099b0b46c284d136a7ef49c74c2ea"
 
 type-is@~1.6.14:
   version "1.6.14"