From 889125cdc471bcefe5ea9454a69a11007a0342d5 Mon Sep 17 00:00:00 2001
From: dougal83 <dougal83+git@gmail.com>
Date: Thu, 6 Jun 2019 14:48:23 +0100
Subject: [PATCH] fix(loopback4-example-shopping): prevent duplicate user email

Prevent creation of user with email value that belongs to an existing user

fix #103

Signed-off-by: dougal83 <dougal83+git@gmail.com>
---
 .../acceptance/user.controller.acceptance.ts  | 18 ++++++++++++++++++
 .../src/controllers/user.controller.ts        | 19 ++++++++++++++-----
 packages/shopping/src/models/user.model.ts    | 15 ++++++++++++++-
 3 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/packages/shopping/src/__tests__/acceptance/user.controller.acceptance.ts b/packages/shopping/src/__tests__/acceptance/user.controller.acceptance.ts
index 8240aab5c..490d6ab8a 100644
--- a/packages/shopping/src/__tests__/acceptance/user.controller.acceptance.ts
+++ b/packages/shopping/src/__tests__/acceptance/user.controller.acceptance.ts
@@ -38,6 +38,7 @@ describe('UserController', () => {
   before('setupApplication', async () => {
     ({app, client} = await setupApplication());
   });
+  before(migrateSchema);
   before(createPasswordHasher);
   before(givenAnExpiredToken);
 
@@ -114,6 +115,19 @@ describe('UserController', () => {
     );
   });
 
+  it('throws error for POST /users with an existing email', async () => {
+    await client
+      .post('/users')
+      .send(user)
+      .expect(200);
+    const res = await client
+      .post('/users')
+      .send(user)
+      .expect(409);
+
+    expect(res.body.error.message).to.equal('Email value is already taken');
+  });
+
   it('returns a user with given id when GET /users/{id} is invoked', async () => {
     const newUser = await createAUser();
     delete newUser.password;
@@ -249,6 +263,10 @@ describe('UserController', () => {
     await userRepo.deleteAll();
   }
 
+  async function migrateSchema() {
+    await app.migrateSchema();
+  }
+
   async function createAUser() {
     const encryptedPassword = await passwordHasher.hashPassword(user.password);
     const newUser = await userRepo.create(
diff --git a/packages/shopping/src/controllers/user.controller.ts b/packages/shopping/src/controllers/user.controller.ts
index 1715cb070..0e1c1deb7 100644
--- a/packages/shopping/src/controllers/user.controller.ts
+++ b/packages/shopping/src/controllers/user.controller.ts
@@ -5,7 +5,7 @@
 
 import {repository} from '@loopback/repository';
 import {validateCredentials} from '../services/validator';
-import {post, param, get, requestBody} from '@loopback/rest';
+import {post, param, get, requestBody, HttpErrors} from '@loopback/rest';
 import {User, Product} from '../models';
 import {UserRepository} from '../repositories';
 import {RecommenderService} from '../services/recommender.service';
@@ -52,11 +52,20 @@ export class UserController {
     // encrypt the password
     user.password = await this.passwordHasher.hashPassword(user.password);
 
-    // create the new user
-    const savedUser = await this.userRepository.create(user);
-    delete savedUser.password;
+    try {
+      // create the new user
+      const savedUser = await this.userRepository.create(user);
+      delete savedUser.password;
 
-    return savedUser;
+      return savedUser;
+    } catch (error) {
+      // MongoError 11000 duplicate key
+      if (error.code === 11000 && error.errmsg.includes('index: uniqueEmail')) {
+        throw new HttpErrors.Conflict('Email value is already taken');
+      } else {
+        throw error;
+      }
+    }
   }
 
   @get('/users/{userId}', {
diff --git a/packages/shopping/src/models/user.model.ts b/packages/shopping/src/models/user.model.ts
index 371e6b8d1..2235a0cf6 100644
--- a/packages/shopping/src/models/user.model.ts
+++ b/packages/shopping/src/models/user.model.ts
@@ -6,7 +6,20 @@
 import {Entity, model, property, hasMany} from '@loopback/repository';
 import {Order} from './order.model';
 
-@model()
+@model({
+  settings: {
+    indexes: {
+      uniqueEmail: {
+        keys: {
+          email: 1,
+        },
+        options: {
+          unique: true,
+        },
+      },
+    },
+  },
+})
 export class User extends Entity {
   @property({
     type: 'string',