From eb02af93b6d7516a242aec74b99a104c29c832e6 Mon Sep 17 00:00:00 2001
From: Andrey Lushnikov <lushnikov@chromium.org>
Date: Tue, 20 Jun 2017 19:26:16 -0700
Subject: [PATCH] Improve error reporting when chrome fails to start

This patch starts throwing exception and dumping chromium stderr when
the browser fails to start.

References #33
---
 lib/Browser.js | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/lib/Browser.js b/lib/Browser.js
index 7ed797813ca..e6452462706 100644
--- a/lib/Browser.js
+++ b/lib/Browser.js
@@ -99,6 +99,8 @@ class Browser {
         if (this._chromeProcess)
             return;
         this._chromeProcess = childProcess.spawn(this._chromeExecutable, this._chromeArguments, {});
+        var stderr = '';
+        this._chromeProcess.stderr.on('data', data => stderr += data.toString('utf8'));
         // Cleanup as processes exit.
         process.on('exit', () => this._chromeProcess.kill());
         this._chromeProcess.on('exit', () => {
@@ -106,7 +108,9 @@ class Browser {
             removeRecursive(this._userDataDir);
         });
 
-        await waitForChromeResponsive(this._remoteDebuggingPort);
+        await waitForChromeResponsive(this._remoteDebuggingPort, () => !this._terminated);
+        if (this._terminated)
+            throw new Error('Failed to launch chrome! ' + stderr);
     }
 
     close() {
@@ -118,7 +122,7 @@ class Browser {
 
 module.exports = Browser;
 
-function waitForChromeResponsive(remoteDebuggingPort) {
+function waitForChromeResponsive(remoteDebuggingPort, shouldWaitCallback) {
     var fulfill;
     var promise = new Promise(x => fulfill = x);
     var options = {
@@ -135,7 +139,12 @@ function waitForChromeResponsive(remoteDebuggingPort) {
         var req = http.request(options, res => {
             fulfill();
         });
-        req.on('error', e => setTimeout(sendRequest, probeTimeout));
+        req.on('error', e => {
+            if (shouldWaitCallback())
+                setTimeout(sendRequest, probeTimeout);
+            else
+                fulfill();
+        });
         req.end();
     }
 }