use compression middleware

app.js

@@ -7,6 +7,7 @@ const config = require('./config');
 const db = require('./config/db');
 const path = require('path');
 const hsts = require('hsts');
+const compression = require('compression');
 const { redirectToHTTPS } = require('express-http-to-https');
 
 require('./models/TodoList');
@@ -17,6 +18,7 @@ const app = express();
 app.use(bodyParser.urlencoded({ extended: false }));
 app.use(bodyParser.json());
 app.use(cors());
+app.use(compression());
 process.env.NODE_ENV === 'production'
   ? app.use(morgan('combined'))
   : app.use(morgan('dev'));

package-lock.json

@@ -1636,6 +1636,35 @@
       "integrity": "sha1-E3kY1teCg/ffemt8WmPhQOaUJeY=",
       "dev": true
     },
+    "compressible": {
+      "version": "2.0.14",
+      "resolved": "https://registry.npmjs.org/compressible/-/compressible-2.0.14.tgz",
+      "integrity": "sha1-MmxfUH+7BV9UEWeCuWmoG2einac=",
+      "requires": {
+        "mime-db": ">= 1.34.0 < 2"
+      },
+      "dependencies": {
+        "mime-db": {
+          "version": "1.34.0",
+          "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.34.0.tgz",
+          "integrity": "sha1-RS0Oz/XDA0am3B5kseruDTcZ/5o="
+        }
+      }
+    },
+    "compression": {
+      "version": "1.7.2",
+      "resolved": "http://registry.npmjs.org/compression/-/compression-1.7.2.tgz",
+      "integrity": "sha1-qv+81qr4VLROuygDU9WtFlH1mmk=",
+      "requires": {
+        "accepts": "~1.3.4",
+        "bytes": "3.0.0",
+        "compressible": "~2.0.13",
+        "debug": "2.6.9",
+        "on-headers": "~1.0.1",
+        "safe-buffer": "5.1.1",
+        "vary": "~1.1.2"
+      }
+    },
     "concat-map": {
       "version": "0.0.1",
       "resolved": "https://registry.npmjs.org/concat-map/-/concat-map-0.0.1.tgz",

package.json

@@ -20,6 +20,7 @@
   "author": "",
   "dependencies": {
     "body-parser": "^1.18.3",
+    "compression": "^1.7.2",
     "cors": "^2.8.4",
     "dotenv": "^5.0.1",
     "express": "^4.16.3",