Enable Route testing with async await

Add regenerator runtime in jest config. see this [closed issue](https://github.com/facebook/jest/issues/5698)

jest.config.js

-module.exports = {};
+module.exports = {
+  setupFiles: ['<rootDir>/node_modules/regenerator-runtime/runtime']
+};

package-lock.json

@@ -1666,6 +1666,12 @@
       "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.0.6.tgz",
       "integrity": "sha1-4wOogrNCzD7oylE6eZmXNNqzriw="
     },
+    "cookiejar": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/cookiejar/-/cookiejar-2.1.2.tgz",
+      "integrity": "sha512-Mw+adcfzPxcPeI+0WlvRrr/3lGVO0bD75SxX6811cxSh1Wbxx7xZBGK1eVtDf6si8rg2lhnUjsVLMFMfbRIuwA==",
+      "dev": true
+    },
     "copy-descriptor": {
       "version": "0.1.1",
       "resolved": "https://registry.npmjs.org/copy-descriptor/-/copy-descriptor-0.1.1.tgz",
@@ -2588,6 +2594,12 @@
         "mime-types": "^2.1.12"
       }
     },
+    "formidable": {
+      "version": "1.2.1",
+      "resolved": "https://registry.npmjs.org/formidable/-/formidable-1.2.1.tgz",
+      "integrity": "sha512-Fs9VRguL0gqGHkXS5GQiMCr1VhZBxz0JnJs4JmMp/2jL18Fmbzvv7vOFRU+U8TBkHEE/CX1qDXzJplVULgsLeg==",
+      "dev": true
+    },
     "forwarded": {
       "version": "0.1.2",
       "resolved": "https://registry.npmjs.org/forwarded/-/forwarded-0.1.2.tgz",
@@ -6419,6 +6431,51 @@
       "integrity": "sha1-PFMZQukIwml8DsNEhYwobHygpgo=",
       "dev": true
     },
+    "superagent": {
+      "version": "3.8.3",
+      "resolved": "https://registry.npmjs.org/superagent/-/superagent-3.8.3.tgz",
+      "integrity": "sha512-GLQtLMCoEIK4eDv6OGtkOoSMt3D+oq0y3dsxMuYuDvaNUvuT8eFBuLmfR0iYYzHC1e8hpzC6ZsxbuP6DIalMFA==",
+      "dev": true,
+      "requires": {
+        "component-emitter": "^1.2.0",
+        "cookiejar": "^2.1.0",
+        "debug": "^3.1.0",
+        "extend": "^3.0.0",
+        "form-data": "^2.3.1",
+        "formidable": "^1.2.0",
+        "methods": "^1.1.1",
+        "mime": "^1.4.1",
+        "qs": "^6.5.1",
+        "readable-stream": "^2.3.5"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "3.2.6",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-3.2.6.tgz",
+          "integrity": "sha512-mel+jf7nrtEl5Pn1Qx46zARXKDpBbvzezse7p7LqINmdoIk8PYP5SySaxEmYv6TZ0JyEKA1hsCId6DIhgITtWQ==",
+          "dev": true,
+          "requires": {
+            "ms": "^2.1.1"
+          }
+        },
+        "ms": {
+          "version": "2.1.1",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.1.tgz",
+          "integrity": "sha512-tgp+dl5cGk28utYktBsrFqA7HKgrhgPsg6Z/EfhWI4gl1Hwq8B/GmY/0oXZ6nF8hDVesS/FpnYaD/kOWhYQvyg==",
+          "dev": true
+        }
+      }
+    },
+    "supertest": {
+      "version": "3.4.2",
+      "resolved": "https://registry.npmjs.org/supertest/-/supertest-3.4.2.tgz",
+      "integrity": "sha512-WZWbwceHUo2P36RoEIdXvmqfs47idNNZjCuJOqDz6rvtkk8ym56aU5oglORCpPeXGxT7l9rkJ41+O1lffQXYSA==",
+      "dev": true,
+      "requires": {
+        "methods": "^1.1.2",
+        "superagent": "^3.8.3"
+      }
+    },
     "supports-color": {
       "version": "5.5.0",
       "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-5.5.0.tgz",

package.json

@@ -23,10 +23,12 @@
     "@babel/cli": "^7.2.3",
     "@babel/core": "^7.2.2",
     "@babel/node": "^7.2.2",
+    "@babel/polyfill": "^7.2.5",
     "@babel/preset-env": "^7.3.1",
     "eslint": "^5.13.0",
     "eslint-plugin-import": "^2.16.0",
     "jest": "^24.1.0",
-    "nodemon": "^1.18.9"
+    "nodemon": "^1.18.9",
+    "supertest": "^3.4.2"
   }
 }

src/__tests__/index.test.js

+import request from 'supertest';
+import app from '../app';
+
 describe('sample test', () => {
   it('jest works', () => {
     expect(true).toBe(true);
   });
 });
+
+describe('index route', () => {
+  it('responds 200', async () => {
+    const response = await request(app).get('/');
+    expect(response.statusCode).toBe(200);
+  });
+});