Parse JSON in JavaScript

Author: timfish

module.cc

@@ -467,18 +467,13 @@ void CaptureStackTraces(const FunctionCallbackInfo<Value> &args) {
           capture_from_isolate, result.poll_state.c_str(),
           NewStringType::kNormal);
       if (!stateStr.IsEmpty()) {
-        v8::MaybeLocal<v8::Value> maybeStateVal =
-            v8::JSON::Parse(current_context, stateStr.ToLocalChecked());
-        v8::Local<v8::Value> stateVal;
-        if (maybeStateVal.ToLocal(&stateVal)) {
-          threadObj
-              ->Set(current_context,
-                    String::NewFromUtf8(capture_from_isolate, "pollState",
-                                        NewStringType::kInternalized)
-                        .ToLocalChecked(),
-                    stateVal)
-              .Check();
-        }
+        threadObj
+            ->Set(current_context,
+                  String::NewFromUtf8(capture_from_isolate, "pollState",
+                                      NewStringType::kInternalized)
+                      .ToLocalChecked(),
+                  stateStr.ToLocalChecked())
+            .Check();
       }
     }
 
@@ -487,18 +482,13 @@ void CaptureStackTraces(const FunctionCallbackInfo<Value> &args) {
           capture_from_isolate, result.stack_trace.async_state.c_str(),
           NewStringType::kNormal);
       if (!stateStr.IsEmpty()) {
-        v8::MaybeLocal<v8::Value> maybeStateVal =
-            v8::JSON::Parse(current_context, stateStr.ToLocalChecked());
-        v8::Local<v8::Value> stateVal;
-        if (maybeStateVal.ToLocal(&stateVal)) {
-          threadObj
-              ->Set(current_context,
-                    String::NewFromUtf8(capture_from_isolate, "asyncState",
-                                        NewStringType::kInternalized)
-                        .ToLocalChecked(),
-                    stateVal)
-              .Check();
-        }
+        threadObj
+            ->Set(current_context,
+                  String::NewFromUtf8(capture_from_isolate, "asyncState",
+                                      NewStringType::kInternalized)
+                      .ToLocalChecked(),
+                  stateStr.ToLocalChecked())
+            .Check();
       }
     }
 

src/index.ts

@@ -49,7 +49,7 @@ interface Native {
   registerThread(threadName: string): void;
   registerThread(storage: AsyncStorageArgs, threadName: string): void;
   threadPoll(enableLastSeen?: boolean, pollState?: object): void;
-  captureStackTrace<A = unknown, P = unknown>(): Record<string, Thread<A, P>>;
+  captureStackTrace(): Record<string, Thread<string, string>>;
   getThreadsLastSeen(): Record<string, number>;
 }
 
@@ -230,7 +230,20 @@ export function threadPoll(enableLastSeen: boolean = true, pollState?: object):
  * Captures stack traces for all registered threads.
  */
 export function captureStackTrace<A = unknown, P = unknown>(): Record<string, Thread<A, P>> {
-  return native.captureStackTrace<A, P>();
+  const result = native.captureStackTrace();
+
+  // Parse the asyncState and pollState from JSON strings back into objects
+  const transformedResult: Record<string, Thread<A, P>> = {};
+  for (const [key, value] of Object.entries(result)) {
+    const thread: Thread<A, P> = {
+      frames: value.frames,
+      ...(value.asyncState && { asyncState: JSON.parse(value.asyncState) }),
+      ...(value.pollState && { pollState: JSON.parse(value.pollState) }),
+    };
+    transformedResult[key] = thread;
+  }
+
+  return transformedResult;
 }
 
 /**