Refactor the File class to use a separate event emitter module for better code organization and separation of concerns

src/models/file.js

@@ -7,11 +7,10 @@ const http = require('http');
 const https = require('https');
 const exec = util.promisify(require('child_process').exec);
 
-const EventEmitter = require('events');
 const csvParser = require('csv-parser');
 const { PassThrough } = require('stream');
 const slugify = require('slugify');
-const e = require('express');
+const emitter = require('../services/eventEmitter');
 
 // Load project path from config/constants.js
 const { basedir } = require('../config/constants');
@@ -29,7 +28,7 @@ function generateFilePath(filename) {
 
 
 // Create a class File that extends EventEmitter
-class File extends EventEmitter {
+class File {
 
   /**
    * Create a new File instance
@@ -57,13 +56,13 @@ class File extends EventEmitter {
     const request = url.protocol === 'https:' ? https : http;
 
     // Emit a download.start event with the url and filepath
-    this.emit('download.start', { url: this.url, filepath: this.filepath });
+    emitter.emit('download.start', { url: this.url, filepath: this.filepath });
 
     // Handle file errors
     file.on('error', (err) => {
       fs.unlink(filepath, () => {
         // Emit a download.error event with the error
-        this.emit('download.error', { url: this.url, filepath: this.filepath, error: err.message, type: 'file' });
+        emitter.emit('download.error', { url: this.url, filepath: this.filepath, error: err.message, type: 'file' });
       });
     });
 
@@ -73,7 +72,7 @@ class File extends EventEmitter {
         // Check if response is valid
         if (response.statusCode !== 200) {
           // Emit a download.error event with the error
-          this.emit('download.error', { url: this.url, filepath: this.filepath, error: response.statusMessage, type: 'response' });
+          emitter.emit('download.error', { url: this.url, filepath: this.filepath, error: response.statusMessage, type: 'response' });
           return reject(response.statusMessage);
         }
 
@@ -93,7 +92,7 @@ class File extends EventEmitter {
           // Check if the downloaded size is bigger than the step limit
           if (downloaded > stepLimit) {
             // Emit a download.progress event with the url, filepath and downloaded size
-            this.emit('download.progress', { url: this.url, filepath: this.filepath, percentage: Math.floor((downloaded / contentLength) * 100) });
+            emitter.emit('download.progress', { url: this.url, filepath: this.filepath, percentage: Math.floor((downloaded / contentLength) * 100) });
             stepLimit += step;
           }
         });
@@ -102,7 +101,7 @@ class File extends EventEmitter {
 
         file.on('finish', () => {
           // Emit a download.end event with the url and filepath
-          this.emit('download.end', { url: this.url, filepath: this.filepath });
+          emitter.emit('download.end', { url: this.url, filepath: this.filepath });
           file.close(() => {
             resolve(filepath);
           });
@@ -111,7 +110,7 @@ class File extends EventEmitter {
       .on('error', (err) => {
         fs.unlink(filepath, () => {
           // Emit a download.error event with the error
-          this.emit('download.error', { url: this.url, filepath: this.filepath, error: err.message, type: 'request' });
+          emitter.emit('download.error', { url: this.url, filepath: this.filepath, error: err.message, type: 'request' });
           reject(err.message);
         });
       });
@@ -145,11 +144,11 @@ class File extends EventEmitter {
     .pipe(csvParser({ separator: ';' }))
     .on('headers', (headers) => {
       // Emit a parse.start event with the url and filepath
-      this.emit('parse.start', { url: this.url, filepath: this.filepath, headers });
+      emitter.emit('parse.start', { url: this.url, filepath: this.filepath, headers });
     })
     .on('data', (row) => {
       // Emit a parse.data event with the url, filepath and data
-      this.emit('parse.data', { url: this.url, filepath: this.filepath, data: row, index: i });
+      emitter.emit('parse.data', { url: this.url, filepath: this.filepath, data: row, index: i });
 
       let result = [];
       if ( i === 0 ) {
@@ -170,11 +169,11 @@ class File extends EventEmitter {
     })
     .on('error', (err) => {
       // Emit a parse.error event with the error
-      this.emit('parse.error', { url: this.url, filepath: this.filepath, error: err.message });
+      emitter.emit('parse.error', { url: this.url, filepath: this.filepath, error: err.message });
     })
     .on('end', () => {
       // Emit a parse.end event with the url and filepath
-      this.emit('parse.end', { url: this.url, filepath: this.filepath, count: i });
+      emitter.emit('parse.end', { url: this.url, filepath: this.filepath, count: i });
       stream.end();
     });