Merge pull request #155 from shirish87/pr-gzip

feat: support for gzip download

Author: yashdsaraf

lib/LocalBinary.js

@@ -4,27 +4,33 @@ var https = require('https'),
   path = require('path'),
   os = require('os'),
   childProcess = require('child_process'),
+  zlib = require('zlib'),
   HttpsProxyAgent = require('https-proxy-agent'),
+  version = require('../package.json').version,
   LocalError = require('./LocalError');
 
+const packageName = 'browserstack-local-nodejs';
+
 function LocalBinary(){
   this.hostOS = process.platform;
   this.is64bits = process.arch == 'x64';
 
   this.getDownloadPath = function () {
+    let sourceURL = 'https://www.browserstack.com/local-testing/downloads/binaries/';
+
     if(this.hostOS.match(/darwin|mac os/i)){
-      return 'https://www.browserstack.com/local-testing/downloads/binaries/BrowserStackLocal-darwin-x64';
+      return sourceURL + 'BrowserStackLocal-darwin-x64';
     } else if(this.hostOS.match(/mswin|msys|mingw|cygwin|bccwin|wince|emc|win32/i)) {
       this.windows = true;
-      return 'https://www.browserstack.com/local-testing/downloads/binaries/BrowserStackLocal.exe';
+      return sourceURL + 'BrowserStackLocal.exe';
     } else {
       if(this.is64bits) {
         if(this.isAlpine())
-          return 'https://www.browserstack.com/local-testing/downloads/binaries/BrowserStackLocal-alpine';
+          return sourceURL + 'BrowserStackLocal-alpine';
         else
-          return 'https://www.browserstack.com/local-testing/downloads/binaries/BrowserStackLocal-linux-x64';
+          return sourceURL + 'BrowserStackLocal-linux-x64';
       } else {
-        return 'https://www.browserstack.com/local-testing/downloads/binaries/BrowserStackLocal-linux-ia32';
+        return sourceURL + 'BrowserStackLocal-linux-ia32';
       }
     }
   };
@@ -81,7 +87,9 @@ function LocalBinary(){
     }
 
     try{
-      const obj = childProcess.spawnSync(cmd, opts);
+      const userAgent = [packageName, version].join('/');
+      const env = Object.assign({ 'USER_AGENT': userAgent }, process.env);
+      const obj = childProcess.spawnSync(cmd, opts, { env: env });
       let output;
       if(obj.stdout.length > 0) {
         if(fs.existsSync(binaryPath)){
@@ -122,12 +130,27 @@ function LocalBinary(){
       try {
         options.ca = fs.readFileSync(conf.useCaCertificate);
       } catch(err) {
-        console.log("failed to read cert file", err)
+        console.log('failed to read cert file', err);
       }
     }
 
+    options.headers = Object.assign({}, options.headers, {
+      'accept-encoding': 'gzip, *',
+      'user-agent': [packageName, version].join('/'),
+    });
+
     https.get(options, function (response) {
-      response.pipe(fileStream);
+      const contentEncoding = response.headers['content-encoding'];
+      if (typeof contentEncoding === 'string' && contentEncoding.match(/gzip/i)) {
+        if (process.env.BROWSERSTACK_LOCAL_DEBUG_GZIP) {
+          console.info('Using gzip in ' + options.headers['user-agent']);
+        }
+
+        response.pipe(zlib.createGunzip()).pipe(fileStream);
+      } else {
+        response.pipe(fileStream);
+      }
+
       response.on('error', function(err) {
         console.error('Got Error in binary download response', err);
         that.retryBinaryDownload(conf, destParentDir, callback, retries, binaryPath);

lib/download.js

@@ -1,7 +1,8 @@
 const https = require('https'),
   fs = require('fs'),
   HttpsProxyAgent = require('https-proxy-agent'),
-  url = require('url');
+  url = require('url'),
+  zlib = require('zlib');
 
 const binaryPath = process.argv[2], httpPath = process.argv[3], proxyHost = process.argv[4], proxyPort = process.argv[5], useCaCertificate = process.argv[6];
 
@@ -17,13 +18,28 @@ if(proxyHost && proxyPort) {
     try {
       options.ca = fs.readFileSync(useCaCertificate);
     } catch(err) {
-      console.log("failed to read cert file", err)
+      console.log('failed to read cert file', err);
     }
   }
 }
 
+options.headers = Object.assign({}, options.headers, {
+  'accept-encoding': 'gzip, *',
+  'user-agent': process.env.USER_AGENT,
+});
+
 https.get(options, function (response) {
-  response.pipe(fileStream);
+  const contentEncoding = response.headers['content-encoding'];
+  if (typeof contentEncoding === 'string' && contentEncoding.match(/gzip/i)) {
+    if (process.env.BROWSERSTACK_LOCAL_DEBUG_GZIP) {
+      console.info('Using gzip in ' + options.headers['user-agent']);
+    }
+
+    response.pipe(zlib.createGunzip()).pipe(fileStream);
+  } else {
+    response.pipe(fileStream);
+  }
+
   response.on('error', function(err) {
     console.error('Got Error in binary download response', err);
   });