inspector: libuv notification on incoming message

Currently Inspector posts a V8 "task" when a message is incoming. To
make sure messages are processed even when no JS is executed (e.g. while
waiting for I/O or timer), inspector will now post a libuv request.

Fixes: https://github.com/nodejs/node/issues/11589
PR-URL: https://github.com/nodejs/node/pull/11617
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

2 files changed, 38 insertions, 3 deletions

diff --git a/test/inspector/inspector-helper.js b/test/inspector/inspector-helper.js
index 3f3fe17e2e0..beaf1a8aa1a 100644
--- a/test/inspector/inspector-helper.js
+++ b/test/inspector/inspector-helper.js
@@ -427,9 +427,24 @@ Harness.prototype.expectShutDown = function(errorCode) {
   });
 };
 
-exports.startNodeForInspectorTest = function(callback) {
-  const child = spawn(process.execPath,
-      [ '--inspect-brk', mainScript ]);
+Harness.prototype.kill = function() {
+  return this.enqueue_((callback) => {
+    this.process_.kill();
+    callback();
+  });
+};
+
+exports.startNodeForInspectorTest = function(callback,
+                                             inspectorFlag = '--inspect-brk',
+                                             opt_script_contents) {
+  const args = [inspectorFlag];
+  if (opt_script_contents) {
+    args.push('-e', opt_script_contents);
+  } else {
+    args.push(mainScript);
+  }
+
+  const child = spawn(process.execPath, args);
 
   const timeoutId = timeout('Child process did not start properly', 4);
 
diff --git a/test/inspector/test-not-blocked-on-idle.js b/test/inspector/test-not-blocked-on-idle.js
new file mode 100644
index 00000000000..6d32888b44b
--- /dev/null
+++ b/test/inspector/test-not-blocked-on-idle.js
@@ -0,0 +1,20 @@
+'use strict';
+require('../common');
+const helper = require('./inspector-helper.js');
+
+function shouldShutDown(session) {
+  session
+    .sendInspectorCommands([
+        { 'method': 'Debugger.enable' },
+        { 'method': 'Debugger.pause' },
+    ])
+    .disconnect(true);
+}
+
+function runTests(harness) {
+  // 1 second wait to make sure the inferior began running the script
+  setTimeout(() => harness.runFrontendSession([shouldShutDown]).kill(), 1000);
+}
+
+const script = 'setInterval(() => {debugger;}, 60000);';
+helper.startNodeForInspectorTest(runTests, '--inspect', script);