Use file-logging directly from local binary

Author: vedharish

lib/browserStackTunnel.js

@@ -1,6 +1,7 @@
 var childProcess = require('child_process'),
   ZipBinary = require('./ZipBinary'),
-  Helper = require('./helper');
+  Helper = require('./helper'),
+  Tail = require('tail').Tail;
 
 function BrowserStackTunnel(options) {
   var helper = new Helper.helper();
@@ -19,7 +20,11 @@ function BrowserStackTunnel(options) {
       }
     },
     doneStop = function(params) {
-      if(stopCallback !== null) {
+      if (this.tail) {
+        this.tail.unwatch();
+        this.tail = null;
+      }
+      if(stopCallback) {
         stopCallback(params);
       }
     };
@@ -28,6 +33,7 @@ function BrowserStackTunnel(options) {
 
   this.stdoutData = '';
   this.tunnel = null;
+  this.tail = null;
 
   if (options.hosts) {
     params.push(options.hosts);
@@ -83,7 +89,6 @@ function BrowserStackTunnel(options) {
   };
 
   this.updateState = function (data) {
-    helper.logBinaryOutput(data.toString());
     var state;
     this.stdoutData += data.toString();
     for (state in this.stateMatchers) {
@@ -124,6 +129,10 @@ function BrowserStackTunnel(options) {
       this.tunnel.kill();
       this.tunnel = null;
     }
+    if (this.tail) {
+      this.tail.unwatch();
+      this.tail = null;
+    }
   };
 
   this.exit = function () {
@@ -142,10 +151,18 @@ function BrowserStackTunnel(options) {
   this._startTunnel = function () {
     var binaryPath = helper.getBinaryPath();
     this.cleanUp();
+
+    var logFilePath = helper.getLogFilePath();
+    params.push('-logFile', logFilePath);
+
     log.info('Local Binary is located at ' + binaryPath);
     log.info('Local started with args: ' + JSON.stringify(params));
+
+    this.tail = new Tail(logFilePath);
+    this.tail.on('line', this.updateState.bind(this));
+    this.tail.on('error', this.updateState.bind(this));
+
     this.tunnel = childProcess.spawn(binaryPath, binary.args.concat([options.key]).concat(params));
-    this.tunnel.stdout.on('data', this.updateState.bind(this));
     this.tunnel.stderr.on('data', this.updateState.bind(this));
     this.tunnel.on('error', this.killTunnel.bind(this));
     this.tunnel.on('exit', this.exit.bind(this));
@@ -181,6 +198,10 @@ function BrowserStackTunnel(options) {
       stopCallback = callback;
     } else if (this.state !== 'started') {
       var err = new Error('child not started');
+      if (this.tail) {
+        this.tail.unwatch();
+        this.tail = null;
+      }
       callback(err);
     }
 

lib/helper.js

@@ -1,5 +1,4 @@
-var fs = require('fs'),
-  path = require('path'),
+var path = require('path'),
   log = require('npmlog'),
   os = require('os');
 
@@ -21,8 +20,7 @@ function helper() {
   const osHomedir = require('os-homedir');
   const basePaths = [ path.join(osHomedir(), '.browserstack'), path.join(__dirname, '..'), getTempDir() ];
   var currentBaseIndex = 0;
-  var basePath = basePaths[0],
-    appendLogs = true;
+  var basePath = basePaths[0];
 
   const localBinaryName = 'BrowserStackLocal' + ( this.getPlatform() === 'win32' ? '.exe' : '' );
   const logFileName = 'local.log';
@@ -49,23 +47,12 @@ function helper() {
 
   if(process.env.NODE_ENV === 'testing') {
     log.level = 'silent';
-    appendLogs = false;
   }
   this.log = log;
 
-  var getLogFilePath = function() {
+  this.getLogFilePath = function() {
     return path.resolve(path.join(basePath, logFileName));
   };
-  this.logBinaryOutput = function(log) {
-    if(appendLogs) {
-      fs.appendFile(getLogFilePath(), log, function (err) {
-        if(err) {
-          exports.log.warn('Error Ssaving log file to ' + getLogFilePath());
-          appendLogs = false;
-        }
-      });
-    }
-  };
 }
 
 exports.helper = helper;

node-example.js

@@ -32,6 +32,10 @@ var options = {
 };
 
 local.start(options, function(error) {
+  if(error) {
+    console.log("Got Error From Local " + error);
+    process.exit();
+  }
   console.log('Is Running ' + local.isRunning());
   console.log('Started');
 

package.json

@@ -17,6 +17,7 @@
   "dependencies": {
     "npmlog": "2.0.2",
     "os-homedir": "^1.0.1",
+    "tail": "^0.4.0",
     "unzip": "0.1.11"
   },
   "devDependencies": {