test: debug-signal-cluster should not be racey

unref one superfluous timer (as the test suite already has a global
timeout), and improve the state machine to iterate the messages more
reliably.

Ultimately make the test complete more quickly.

Signed-off-by: Julien Gilli <julien.gilli@joyent.com>

test/simple/test-debug-signal-cluster.js

@@ -35,17 +35,11 @@ var pids = null;
 
 child.stderr.on('data', function(data) {
   var lines = data.toString().replace(/\r/g, '').trim().split('\n');
-  var line = lines[0];
 
-  lines.forEach(function(ln) { console.log('> ' + ln) } );
+  lines.forEach(function(line) {
+    console.log('> ' + line);
 
-  if (outputTimerId !== undefined)
-    clearTimeout(outputTimerId);
-
-  if (waitingForDebuggers) {
-    outputLines = outputLines.concat(lines);
-    outputTimerId = setTimeout(onNoMoreLines, 800);
-  } else if (line === 'all workers are running') {
+    if (line === 'all workers are running') {
       child.on('message', function(msg) {
         if (msg.type !== 'pids')
           return;
@@ -60,7 +54,13 @@ child.stderr.on('data', function(data) {
       child.send({
         type: 'getpids'
       });
+    } else if (waitingForDebuggers) {
+      outputLines.push(line);
     }
+
+  });
+  if (outputLines.length >= expectedLines.length)
+    onNoMoreLines();
 });
 
 function onNoMoreLines() {
@@ -70,7 +70,7 @@ function onNoMoreLines() {
 
 setTimeout(function testTimedOut() {
   assert(false, 'test timed out.');
-}, 6000);
+}, 6000).unref();
 
 process.on('exit', function onExit() {
   pids.forEach(function(pid) {
@@ -78,16 +78,16 @@ process.on('exit', function onExit() {
   });
 });
 
-function assertOutputLines() {
-  var expectedLines = [
+var expectedLines = [
   'Starting debugger agent.',
   'Debugger listening on port ' + 5858,
   'Starting debugger agent.',
   'Debugger listening on port ' + 5859,
   'Starting debugger agent.',
   'Debugger listening on port ' + 5860,
-  ];
+];
 
+function assertOutputLines() {
   // Do not assume any particular order of output messages,
   // since workers can take different amout of time to
   // start up