Small refactor according to Node.js best practices

- moved any server related functioonality under server.js
- simplified app.js a bit
- introduced config.env file

Author: Andrey

index.js renamed to app.js

@@ -3,7 +3,6 @@ const fs = require('fs');
 const path = require('path');
 const { PDFNet } = require('@pdftron/pdfnet-node');
 const mimeType = require('./modules/mimeType');
-const port = 9000;
 const filesPath = './files';
 
 const app = express();
@@ -268,10 +267,4 @@ const PDFNetEndpoint = (main, pathname, res) => {
     });
 };
 
-app.listen(port, () =>
-  console.log(
-    `nodejs-convert-file-server listening at http://localhost:${port}`,
-  ),
-);
-
 module.exports = app;

config.env

@@ -0,0 +1 @@
+PORT=9000

files/document.docx.pdf

@@ -4,13 +4,14 @@
   "description": "This is an example how to use PDFTron Custom Server - Node JS SDK",
   "main": "index.js",
   "scripts": {
-    "start": "nodemon index.js",
+    "start": "nodemon server.js",
     "test": "mocha --timeout 10000"
   },
   "author": "",
   "license": "ISC",
   "dependencies": {
     "@pdftron/pdfnet-node": "^7.1.1",
+    "dotenv": "^8.2.0",
     "express": "^4.17.1",
     "nodemon": "^2.0.3"
   },

files/new.pdf

@@ -0,0 +1,10 @@
+const dotenv = require('dotenv');
+dotenv.config({ path: './config.env' });
+
+const app = require('./app');
+
+const port = process.env.PORT;
+
+app.listen(port, () => {
+  console.log(`nodejs-convert-file-server listening at http://localhost:${port}`);
+});