Adding --pid to README.md

* Renaming config.tunnel_pid to config.tunnel_pid_file
* Regex match for --pid instead of -pid
* Error message on invalid flag

Author: pulkitsharma07

README.md

@@ -174,7 +174,7 @@ To run browser tests on BrowserStack infrastructure, you need to create a `brows
  * `build`: A string to identify your test run in Browserstack.  In `TRAVIS` setup `TRAVIS_COMMIT` will be the default identifier.
  * `proxy`: Specify a proxy to use for the local tunnel. Object with `host`, `port`, `username` and `password` properties.
  * `exit_with_fail`: If set to true the cli process will exit with fail if any of the tests failed. Useful for automatic build systems.
- * `tunnel_pid`: Specify a path to file to save the tunnel process id into.
+ * `tunnel_pid_file`: Specify a path to file to save the tunnel process id into. Can also by specified using the `--pid` flag while launching browserstack-runner from the command line.
 
 A sample configuration file:
 

bin/runner.js

@@ -37,9 +37,15 @@ try {
 }
 
 // extract a path to file to store tunnel pid
-var matches, pid = process.argv.find(function (param) { return param.indexOf('--pid') !== -1; });
-if (pid && (matches = /-pid=([\w\/\.-]+)/g.exec(pid))) {
-  config.tunnel_pid = matches[1];
+var pid = process.argv.find(function (param) { return param.indexOf('--pid') !== -1; });
+
+if (pid) {
+  var extracted_path = /--pid=([\w\/\.-]+)/g.exec(pid);
+  if (extracted_path) {
+    config.tunnel_pid_file = extracted_path[1];
+  } else {
+    console.error('Error while parsing flag --pid. Usage: --pid=/path/to/file');
+  }
 }
 
 var runner = require('./cli.js');

lib/local.js

@@ -57,9 +57,9 @@ var Tunnel = function Tunnel(key, port, uniqueIdentifier, config, callback) {
       }
     });
 
-    if (config.tunnel_pid) {
-      utils.mkdirp(path.dirname(config.tunnel_pid));
-      fs.writeFile(config.tunnel_pid, subProcess.pid);
+    if (config.tunnel_pid_file) {
+      utils.mkdirp(path.dirname(config.tunnel_pid_file));
+      fs.writeFile(config.tunnel_pid_file, subProcess.pid);
     }
 
     that.process = subProcess;
@@ -107,8 +107,8 @@ var Tunnel = function Tunnel(key, port, uniqueIdentifier, config, callback) {
         } catch (e) {
           logger.debug('[%s] failed to kill process:', new Date(), e);
         } finally {
-          if (config.tunnel_pid) {
-            fs.unlink(config.tunnel_pid, function () {});
+          if (config.tunnel_pid_file) {
+            fs.unlink(config.tunnel_pid_file, function () {});
           }
         }
       }