[inspector] Expose scopes for suspended generator objects

test/inspector/debugger/suspended-generator-scopes.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+InspectorTest.addScript(
+`function *gen(a) {
+  var b = 42;
+  yield a;
+  return b;
+}
+function testSuspendedGenerator()
+{
+  var g = gen(420);
+  g.next();
+
+  debugger;
+}`);
+
+Protocol.Debugger.enable().then(testSuite);
+
+function dumpInnermostScope(msg) {
+  var scopes = msg.result.result;
+  var inner_scope = scopes[0].value;
+  return Protocol.Runtime.getProperties({ objectId : inner_scope.objectId })
+      .then(InspectorTest.logMessage);
+}
+
+function dumpGeneratorScopes(msg)
+{
+  var props = msg.result.internalProperties;
+  var promises = props
+      .filter(prop => prop.name == "[[Scopes]]")
+      .map(prop => prop.value.objectId)
+      .map(scopesId => Protocol.Runtime.getProperties({ objectId : scopesId })
+          .then(dumpInnermostScope));
+  return Promise.all(promises);
+}
+
+function fetchGeneratorProperties(objectId) {
+  return Protocol.Runtime.getProperties({ objectId : objectId });
+}
+
+function extractGeneratorObjectFromScope(scopeId) {
+  return Protocol.Runtime.getProperties({ objectId : scopeId })
+      .then(msg => {
+          var generatorObjectId = msg.result.result[0].value.objectId;
+          return fetchGeneratorProperties(generatorObjectId);
+      });
+}
+
+function dumpGeneratorScopesOnPause(msg) {
+  var scopeChain = msg.params.callFrames[0].scopeChain;
+  var promises = scopeChain
+      .filter(scope => scope.type === "local")
+      .map(scope => scope.object.objectId)
+      .map(scopeId => extractGeneratorObjectFromScope(scopeId)
+                          .then(dumpGeneratorScopes));
+  return Promise.all(promises).then(Protocol.Debugger.resume);
+}
+
+function testSuite() {
+  InspectorTest.runTestSuite([
+
+    function testScopesPaused(next) {
+      Protocol.Debugger.oncePaused()
+          .then(dumpGeneratorScopesOnPause)
+          .then(next);
+      Protocol.Runtime.evaluate({ expression : "testSuspendedGenerator()" });
+    },
+
+    function testScopesNonPaused(next) {
+      Protocol.Runtime.evaluate({ expression : "gen(430)"})
+          .then(msg => fetchGeneratorProperties(msg.result.result.objectId))
+          .then(dumpGeneratorScopes)
+          .then(next);
+    },
+  ]);
+}