Add some debug output to test-child-process-double-pipe

test/simple/test-child-process-double-pipe.js

@@ -44,6 +44,7 @@ var echo = spawn('echo', ['hello\nnode\nand\nworld\n']),
 
 // pipe echo | grep
 echo.stdout.on('data', function(data) {
+  console.error("grep stdin write " + data.length);
   if (!grep.stdin.write(data)) {
     echo.stdout.pause();
   }
@@ -58,10 +59,23 @@ echo.stdout.on('end', function(code) {
   grep.stdin.end();
 });
 
+echo.on('exit', function() {
+  console.error("echo exit");
+})
+
+grep.on('exit', function() {
+  console.error("grep exit");
+})
+
+sed.on('exit', function() {
+  console.error("sed exit");
+})
+
 
 
 // pipe grep | sed
 grep.stdout.on('data', function(data) {
+  console.error("grep stdout " + data.length);
   if (!sed.stdin.write(data)) {
     grep.stdout.pause();
   }
@@ -73,6 +87,7 @@ sed.stdin.on('drain', function(data) {
 
 // propagate end from grep to sed
 grep.stdout.on('end', function(code) {
+  console.error("grep stdout end");
   sed.stdin.end();
 });