express app startup refactored 🏋🏾‍♂️

backend/src/app.js

@@ -3,47 +3,66 @@ import express from 'express';
 import mongoose from 'mongoose';
 import config from 'config';
 
-/**
- * Configures and connects mongoose to the mongoDB instance
- */
-const configureDB = () => {
-  mongoose.connection.on('connected', () => {
-    console.log(`Mongoose successfully connected to: ${config.db.uri}`);
-  });
-
-  mongoose.connection.on('disconnected', () => {
-    console.log(`Mongoose disconnected from: ${config.db.uri}`);
-  });
-
-  mongoose.connection.on('error', err => {
-    console.log(`Mongoose connection error: ${err}`);
-  });
-
-  mongoose.connect(config.db.uri, {
-    useNewUrlParser: true,
-    useCreateIndex: true,
-    // Use native findOneAndUpdate() rather than findAndModify()
-    useFindAndModify: false,
-  });
-};
-
-const app = express();
-
-SwaggerExpress.create(config.swagger, (err, swaggerExpress) => {
-  if (err) {
-    throw err;
+class App {
+  constructor() {
+    this.app = express();
+    this.configureDB();
+    this.configureSwagger();
   }
 
-  // install middleware
-  swaggerExpress.register(app);
-  // connect db
-  configureDB();
+  /**
+   * Configures the swagger express middleware
+   */
+  configureSwagger() {
+    SwaggerExpress.create(config.swagger, (err, swaggerExpress) => {
+      if (err) {
+        throw err;
+      }
 
-  app.listen(config.server.port, config.server.host, () => {
-    console.log(
-      `API server listening on: http://${config.server.host}:${config.server.port}${config.swagger.basePath}`,
-    );
-  });
-});
+      // Register swagger middleware
+      swaggerExpress.register(this.app);
+      // Start express app
+      this.start();
+    });
+  }
+
+  /**
+   * Configures and connects mongoose to the mongoDB instance
+   */
+  // eslint-disable-next-line class-methods-use-this
+  configureDB() {
+    mongoose.connection.on('connected', () => {
+      console.log(`Mongoose successfully connected to: ${config.db.uri}`);
+    });
+
+    mongoose.connection.on('disconnected', () => {
+      console.log(`Mongoose disconnected from: ${config.db.uri}`);
+    });
+
+    mongoose.connection.on('error', err => {
+      console.log(`Mongoose connection error: ${err}`);
+    });
+
+    mongoose.connect(config.db.uri, {
+      useNewUrlParser: true,
+      useCreateIndex: true,
+      // Use native findOneAndUpdate() rather than findAndModify()
+      useFindAndModify: false,
+    });
+  }
+
+  /**
+   * Starts the express app with the settings defined in 'config.server'
+   */
+  start() {
+    this.app.listen(config.server.port, config.server.host, () => {
+      console.log(
+        `API server listening on: http://${config.server.host}:${config.server.port}${config.swagger.basePath}`
+      );
+    });
+  }
+}
+
+const Server = new App();
 
-export default app;
+export default Server.app;

backend/test/api/controllers/index.test.js

@@ -3,7 +3,7 @@ import mongoose from 'mongoose';
 // Clear database before each test case
 before(done => {
   Object.keys(mongoose.connection.collections).map(collection =>
-    mongoose.connection.collections[collection].remove(() => {}),
+    mongoose.connection.collections[collection].remove(() => {})
   );
   done();
 });