inspector: fix crash when the IsolateData has no platform

An embedder that creates its IsolateData without a MultiIsolatePlatform
(allowed; node.h says only Workers need one) and keeps the inspector
segfaulted on the first `console.log()`, `console.time()` or profiler
use after a `node:inspector` session was connected: V8 calls the
inspector client's `currentTimeMS()` there, and
`NodeInspectorClient::currentTimeMS()` dereferenced
`isolate_data()->platform()` unconditionally.

Fall back to the wall clock when there is no platform, which is what
`NodePlatform::CurrentClockTimeMillis()` returns anyway.

Refs: #21917
Signed-off-by: Shelley Vohr <shelley.vohr@gmail.com>
PR-URL: #65818
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>

Author: codebytere

src/inspector_agent.cc

@@ -864,7 +864,9 @@ class NodeInspectorClient : public V8InspectorClient {
   }
 
   double currentTimeMS() override {
-    return env_->isolate_data()->platform()->CurrentClockTimeMillis();
+    MultiIsolatePlatform* platform = env_->isolate_data()->platform();
+    if (platform == nullptr) return GetCurrentTimeInMicroseconds() / 1000;
+    return platform->CurrentClockTimeMillis();
   }
 
   std::unique_ptr<StringBuffer> resourceNameToUrl(

test/cctest/test_environment.cc

@@ -702,6 +702,34 @@ TEST_F(EnvironmentTest, InspectorMultipleEmbeddedEnvironments) {
   CHECK_EQ(data.extracted_value, 42);
   CHECK_EQ(from_inspector->IntegerValue(context).FromJust(), 42);
 }
+
+TEST_F(EnvironmentTest, InspectorWithoutPlatform) {
+  const v8::HandleScope handle_scope(isolate_);
+  const Argv argv;
+  node::IsolateData* isolate_data = node::CreateIsolateData(
+      isolate_, &NodeTestFixture::current_loop, nullptr);
+  v8::Local<v8::Context> context = node::NewContext(isolate_);
+  v8::Context::Scope context_scope(context);
+  std::vector<std::string> args(*argv, *argv + 1);
+  node::Environment* env =
+      node::CreateEnvironment(isolate_data, context, args, args);
+  CHECK_NOT_NULL(env);
+
+  v8::Local<v8::Value> result =
+      node::LoadEnvironment(env,
+                            "const { Session } = require('inspector');\n"
+                            "const session = new Session();\n"
+                            "session.connect();\n"
+                            "console.time('t'); console.timeEnd('t');\n"
+                            "session.disconnect();\n"
+                            "return 42;")
+          .ToLocalChecked();
+  EXPECT_EQ(result->Int32Value(context).FromJust(), 42);
+
+  node::FreeEnvironment(env);
+  node::FreeIsolateData(isolate_data);
+}
+
 #endif  // HAVE_INSPECTOR
 
 TEST_F(EnvironmentTest, ExitHandlerTest) {