feat(download): refactor, remove flow and add some more events

.babelrc

@@ -9,7 +9,6 @@
     ]
   ],
   "plugins": [
-    "babel-plugin-syntax-flow",
-    "babel-plugin-transform-flow-strip-types"
+    ["transform-object-rest-spread", { "useBuiltIns": true }]
   ]
 }

README.md

@@ -65,17 +65,19 @@ download.on('progress', data => {
 download.on('error', err => {
   console.log('Error', err);
 });
+download.on('connection-finished', data => {
+  console.log('Connection Finished', data);
+});
 download.on('finish', () => {
   console.log('Download Finished!');
 });
 download.on('stop', () => {
-  console.log('Download Stoped!');
+  console.log('Download Stopped!');
 });
 download.start();
-
 ```
 
-`Download` class inherits from EventEmitter. You can listen on it for `start`, `progress`, `error`, `finish`, `stop` events.
+`Download` class inherits from EventEmitter. You can listen on it for `start`, `progress`, `error`, `connection-finished`, `finish`, `stop` events.
 
 *More details will be added.*
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "axel-downloader",
-  "version": "0.1.6",
+  "version": "0.2.0",
   "description": "A node wrapper around axel downloader",
   "main": "lib/index.js",
   "files": [
@@ -20,17 +20,17 @@
   "devDependencies": {
     "ava": "^0.18.1",
     "babel-cli": "^6.22.2",
-    "babel-plugin-syntax-flow": "^6.18.0",
-    "babel-plugin-transform-flow-strip-types": "^6.22.0",
+    "babel-plugin-transform-object-rest-spread": "^6.22.0",
     "babel-preset-env": "^1.1.8",
     "coveralls": "^2.11.16",
     "eslint": "^3.15.0",
-    "eslint-config-airbnb-base": "^11.0.1",
+    "eslint-config-airbnb-base": "^11.1.0",
     "eslint-plugin-import": "^2.2.0",
     "nyc": "^10.1.2"
   },
   "dependencies": {
     "babel-eslint": "^7.1.1",
+    "deep-equal": "^1.0.1",
     "stream-splitter": "^0.3.2"
   },
   "ava": {

src/Download.js

@@ -1,22 +1,21 @@
-// @flow
 import EventEmitter from 'events';
+import deepEqual from 'deep-equal';
 import { spawn } from 'child_process';
 
 import { splitStream, parseProgress } from './helpers';
-import { DownloadOptions } from './types';
 
 
 // A class for download task
 export default class Download extends EventEmitter {
   constructor(
-    url: string,
-    downloadPath: string = process.cwd(),
+    url,
+    downloadPath = process.cwd(),
     {
       connections = 16,
       maxSpeed = 0,
       userAgent,
       headers = []
-    }: DownloadOptions = {}
+    } = {}
   ) {
     super();
 
@@ -30,10 +29,11 @@ export default class Download extends EventEmitter {
     this.userAgent = userAgent;
     this.headers = headers;
     this.childProcess = null;
+    this.status = {};
   }
 
   // Start download
-  start(): void {
+  start() {
     Download.checkAxel();
 
     this.childProcess = spawn('axel', this.getCommandArgs());
@@ -43,20 +43,37 @@ export default class Download extends EventEmitter {
 
     stdout.on('token', (data) => {
       const rawDownloadProgress = data.toString();
-      const progressInfo = parseProgress(rawDownloadProgress);
-      this.emit('progress', progressInfo);
+      const operation = parseProgress(rawDownloadProgress);
+
+      switch (operation.type) {
+        case 'start':
+          this.emit('start');
+          break;
+        case 'progress':
+          if (!deepEqual(operation.data, this.status)) {
+            this.status = operation.data;
+            this.emit('progress', operation.data);
+          }
+          break;
+        case 'connection-finished':
+          this.emit('connection-finished', operation.data);
+          break;
+        default:
+          // nothing for now
+      }
     });
-    stdout.on('close', () => {
+
+    this.childProcess.stdout.on('close', () => {
       this.emit('finish');
     });
+
     stderr.on('data', (err) => {
       this.emit('error', err.toString());
     });
-    this.emit('start');
   }
 
   // Stop download
-  stop(): void {
+  stop() {
     if (this.childProcess) {
       this.childProcess.kill();
       this.childProcess = null;
@@ -65,7 +82,7 @@ export default class Download extends EventEmitter {
   }
 
   // Get axel command arguments
-  getCommandArgs(): Array<string> {
+  getCommandArgs() {
     const args = [];
 
     // download path
@@ -100,7 +117,7 @@ export default class Download extends EventEmitter {
   }
 
   // Check if axel downloader is installed
-  static checkAxel(): void {
+  static checkAxel() {
     const axelCheck = spawn('axel');
     axelCheck.on('error', () => {
       throw new Error('Axel is not installed or is not available in your path');

src/helpers.js

@@ -1,31 +1,60 @@
-// @flow
 import StreamSplitter from 'stream-splitter';
 
-import { DownloadProgress } from './types';
 
+// Download operations
+const downloadOperations = [
+  {
+    type: 'start',
+    pattern: /Starting download/,
+    props: []
+  },
+  {
+    type: 'progress',
+    pattern: /\[\s+(\d+)%][\s.]+\[\s*(\d+\.?\d)KB\/s]/,
+    props: [
+      'progress',
+      'speed'
+    ]
+  },
+  {
+    type: 'connection-finished',
+    pattern: /Connection\s(\d+)\sfinished/,
+    props: [
+      'number'
+    ]
+  }
+];
 
 // Get a stream that splits on a token
-export function splitStream(stream: any, token: string = '\n'): any {
+export function splitStream(stream, token = '\n') {
   return stream.pipe(StreamSplitter(token));
 }
 
-// Get progress and speed of download from a line of string stdout
-export function parseProgress(rawDownloadProgress: string): DownloadProgress {
-  const regexPattern = /\[\s+(\d+)%][\s.]+\[\s*(\d+\.?\d)KB\/s]/;
-  const matchedPatterns = rawDownloadProgress.match(regexPattern);
+// Parse stdout and return operation type and params
+export function parseProgress(rawDownloadProgress) {
+  const operation = downloadOperations.find(item => rawDownloadProgress.match(item.pattern));
 
-  if (!matchedPatterns) {
+  if (!operation) {
     return {
-      downloading: false,
-      progress: 0,
-      speed: 0
+      type: 'none'
     };
   }
 
-  const [progress, speed] = [Number(matchedPatterns[1]), Number(matchedPatterns[2])];
-  return {
-    downloading: true,
-    progress,
-    speed
-  };
+  const matchedPattern = rawDownloadProgress.match(operation.pattern);
+  matchedPattern.shift();
+
+  const result = operation.props.reduce((acc, curr) => (
+    {
+      type: acc.type,
+      data: {
+        ...acc.data,
+        [curr]: matchedPattern.shift()
+      }
+    }
+  ), {
+    type: operation.type,
+    data: {}
+  });
+
+  return result;
 }

test/helpers.js

@@ -4,17 +4,15 @@ import { parseProgress } from '../src/helpers';
 
 
 test('wrong raw progress', t => {
-  const { downloading, progress, speed } = parseProgress('some wrong raw progress data');
-  t.is(downloading, false);
-  t.is(progress, 0);
-  t.is(speed, 0);
+  const { type } = parseProgress('some wrong raw progress data');
+  t.is(type, 'none');
 });
 
 test('correct raw progress', t => {
-  const { downloading, progress, speed } = parseProgress(
+  const { type, data } = parseProgress(
     '[  79%]  .......... .......... .......... .......... ..........  [   3412.9KB/s]'
   );
-  t.is(downloading, true);
-  t.is(progress, 79);
-  t.is(speed, 3412.9);
+  t.is(type, 'progress');
+  t.is(data.progress, '79');
+  t.is(data.speed, '3412.9');
 });