add some integration tests for the Cat API

package.json

@@ -9,18 +9,21 @@
   },
   "scripts": {
     "start": "ts-node service/server/index.ts",
-    "prettier:check": "prettier --check service/**/*.{ts,tsx,js,jsx}",
-    "prettier:write": "prettier --write service/**/*.{ts,tsx,js,jsx}",
+    "prettier:check": "prettier --check service/**/*.{ts,tsx,jsx}",
+    "prettier:write": "prettier --write service/**/*.{ts,tsx,jsx}",
     "test": "npm run prettier:check && npm run test:unit && npm audit",
-    "test:unit": "_mocha 'service/**/*Spec.ts' --opts service/mocha.opts"
+    "test:unit": "_mocha 'service/**/*Spec.ts' --opts service/mocha.opts",
+    "test:integration": "_mocha 'test/integration/**/*Test.ts' --opts service/mocha.opts"
   },
   "dependencies": {
     "express": "^4.16.2",
-    "compression": "1.7.2",
-    "cookie-parser": "1.4.3",
-    "http-status-codes": "1.3.0",
+    "compression": "^1.7.2",
+    "cookie-parser": "^1.4.3",
+    "http-status-codes": "^1.3.0",
     "connect-datadog": "^0.0.6",
-    "hot-shots": "^4.7.0"
+    "hot-shots": "^4.7.0",
+    "supertest": "^3.0.0",
+    "tslib": "^1.9.3"
   },
   "devDependencies": {
     "@types/chai": "4.1.7",
@@ -30,6 +33,7 @@
     "@types/compression": "0.0.35",
     "@types/cookie-parser": "1.4.1",
     "@types/express": "4.11.1",
+    "@types/supertest": "2.0.4",
     "@types/mocha": "5.2.5",
     "@types/sinon-chai": "3.2.2",
     "chai": "4.2.0",

service/server/ExpressServer.ts

@@ -63,7 +63,7 @@ export class ExpressServer {
 
     private configureApiEndpoints(server: Express) {
         server.get('/api/cat', noCache, this.catEndpoints.getAllCats)
-        server.get('/api/statistics/cat', noCache, this.catEndpoints.getCatStatistics)
+        server.get('/api/statistics/cat', noCache, this.catEndpoints.getCatsStatistics)
         server.get('/api/cat/:catId', noCache, this.catEndpoints.getCatDetails)
     }
 }

test/integration/CatsApiTest.ts

@@ -0,0 +1,71 @@
+import * as request from 'supertest'
+import { expect } from 'chai'
+import * as HttpStatus from 'http-status-codes'
+import TestEnv from './TestEnv'
+
+const { baseUrl } = TestEnv
+
+describe('Cats API', () => {
+    describe('Cat details', () => {
+        it('should respond with a positive status code if the cat is known', () => {
+            return request(baseUrl)
+                .get('/api/cat/1')
+                .expect(HttpStatus.OK)
+        })
+
+        it('should respond with 404 status code if the cat is not known', () => {
+            return request(baseUrl)
+                .get('/api/cat/666')
+                .expect(HttpStatus.NOT_FOUND)
+        })
+
+        it('should respond with cat details data if the cat is known', () => {
+            return request(baseUrl)
+                .get('/api/cat/1')
+                .expect((res: Response) => {
+                    expect(res.body).to.deep.equal({
+                        id: 1,
+                        name: 'Tony Iommi',
+                        breed: 'British Shorthair',
+                        gender: 'male',
+                        age: 71
+                    })
+                })
+        })
+    })
+
+    describe('All cats', () => {
+        it('should respond with a positive status code', () => {
+            return request(baseUrl)
+                .get('/api/cat')
+                .expect(HttpStatus.OK)
+        })
+
+        it('should return a reasonable amount of cats entries', () => {
+            return request(baseUrl)
+                .get('/api/cat')
+                .expect((res: Response) => {
+                    expect((res.body as any).length).to.eq(5)
+                })
+        })
+    })
+
+    describe('Cat statistics', () => {
+        it('should respond with a positive status code', () => {
+            return request(baseUrl)
+                .get('/api/statistics/cat')
+                .expect(HttpStatus.OK)
+        })
+
+        it('should deliver a reasonable statistics response', () => {
+            return request(baseUrl)
+                .get('/api/statistics/cat')
+                .expect((res: Response) => {
+                    expect(res.body).to.deep.eq({
+                        amount: 5,
+                        averageAge: 69.2
+                    })
+                })
+        })
+    })
+})

test/integration/TestEnv.ts

@@ -0,0 +1,4 @@
+export default class TestEnv {
+    public static readonly local = !process.env.BASE_URL
+    public static readonly baseUrl = process.env.BASE_URL || 'http://localhost:8000'
+}