chore:refactor memcached test (#1698)

appengine/memcached/app.js

@@ -43,7 +43,9 @@ app.get('/', async (req, res, next) => {
 });
 
 const PORT = process.env.PORT || 8080;
-app.listen(PORT, () => {
+const server = app.listen(PORT, () => {
   console.log(`App listening on port ${PORT}`);
   console.log('Press Ctrl+C to quit.');
 });
+
+module.exports = server;

appengine/memcached/package.json

@@ -10,13 +10,15 @@
   },
   "scripts": {
     "start": "node app.js",
-    "test": "repo-tools test app"
+    "test": "mocha --exit test/*.test.js"
   },
   "dependencies": {
     "express": "^4.16.4",
     "memjs": "^1.2.0"
   },
   "devDependencies": {
-    "@google-cloud/nodejs-repo-tools": "^3.3.0"
+    "chai": "^4.2.0",
+    "mocha": "^7.1.1",
+    "wait-port": "^0.2.7"
   }
 }

appengine/memcached/test/app.test.js

@@ -0,0 +1,13 @@
+const waitPort = require('wait-port');
+const {expect} = require('chai');
+
+const PORT = process.env.PORT || 8080;
+
+describe('server listening', () => {
+  it('should be listening', async () => {
+    const server = require('../app.js');
+    const isOpen = await waitPort({port: PORT});
+    expect(isOpen).to.be.true;
+    server.close();
+  });
+});