fix(launcher): output error messages when child processes exit with error

Version 0.24.0 introduced a bug where child processes would error without outputting
the error message. Fix. See #902.

Author: juliemr

lib/launcher.js

@@ -93,11 +93,13 @@ var init = function(configFile, additionalConfig) {
     });
 
     this.process.on('error', function(err) {
+      self.reporter.flush();
       log_('Runner Process(' + self.process.pid + ') Error: ' + err);
       launcherExitCode = 1; 
     });
 
     this.process.on('exit', function(code) {
+      self.reporter.flush();
       if (code) {
         log_('Runner Process Exited With Error Code: ' + code);
         launcherExitCode = 1;
@@ -224,7 +226,7 @@ var TaskReporter_ = function(task, pid) {
 TaskReporter_.prototype.reportHeader_ = function() {
   var capability = this.task.capability;
   var eol = require('os').EOL;
-  var output = '------------------------------------' + eol;
+  var output = eol + '------------------------------------' + eol;
   output += 'PID: ' + this.pid + ' (capability: ';
   output += (capability.browserName) ?
     capability.browserName : '';
@@ -267,9 +269,17 @@ TaskReporter_.prototype.logStderr = function(stderr) {
  */
 TaskReporter_.prototype.testsDone = function(failedCount) {
   this.failedCount = failedCount;
+  this.flush();
+};
+
+/**
+ * Flushes the buffer to stdout.
+ */
+TaskReporter_.prototype.flush = function(failedCount) {
   if (this.buffer) {
     // Flush buffer if nonempty
     process.stdout.write(this.buffer);
+    this.buffer = '';
   }
 };