oven-sh/bun · error · Error

Not supported: ${type}

Error message

Not supported: ${type}

What it means

handleMessage() on the VS Code debug session is the inbound path for editor-to-adapter traffic and only accepts DAP messages with type 'request' (it rewrites source paths and forwards to the adapter). Any other message type — a 'response' or 'event' sent toward the session — violates the protocol direction and throws immediately.

Source

Thrown at packages/bun-vscode/src/features/debug.ts:439

    const { type } = message;

    if (type === "request") {
      const { untitledDocPath, bunEvalPath } = this;
      const { command } = message;
      if (command === "setBreakpoints" || command === "breakpointLocations") {
        const args = message.arguments as any;
        if (untitledDocPath && args.source?.path === untitledDocPath) {
          args.source.path = bunEvalPath;
        } else if (args.source?.path) {
          args.source.path = this.mapLocalToRemote(args.source.path);
        }
      } else if (command === "source" && message.arguments?.source?.path) {
        message.arguments.source.path = this.mapLocalToRemote(message.arguments.source.path);
      }

      this.adapter.emit("Adapter.request", message);
    } else {
      throw new Error(`Not supported: ${type}`);
    }
  }

  dispose() {
    this.adapter.close();
  }
}

class TerminalDebugSession extends FileDebugSession {
  signal!: TCPSocketSignal | UnixSignal;

  constructor() {
    super(undefined, undefined);
  }

  async initialize() {
    await super.initialize();
    if (process.platform === "win32") {

View on GitHub (pinned to 8c5296ac45)

Solutions

1. Filter by message type before dispatching: only forward type === 'request' to handleMessage
2. Route responses and events through the adapters' 'Adapter.response'/'Adapter.event' listeners instead
3. If you are replaying traffic, split the transcript by direction first

Example fix

// before
session.handleMessage(message); // may be a response/event -> throws

// after
if (message.type === 'request') session.handleMessage(message);

function isDapRequest(m: { type: string }): boolean {
  return m.type === 'request';
}
if (!isDapRequest(message)) return; // never forward responses/events into handleMessage

const isDapRequest = (m: { type: string }): m is DAP.Request => m.type === 'request';

When it happens

Trigger: A custom extension, test harness, or DAP proxy calling session.sendMessage/sendRequest with a Response or Event object (e.g. replaying recorded adapter traffic back into the session); wiring both ends of a DebugSession to the same emitter.

Common situations: Writing VS Code extension tests that feed captured DAP transcripts into the session; proxies that accidentally loop adapter responses back to the client-side session; custom UIs multiplexing both directions through one handler.

Related errors

• Invalid UNIX path: ${path}
• HTTP2ContentLengthMismatch
• UnknownMessageType

AI-assisted analysis of oven-sh/bun@8c5296ac45 (2026-08-16). Data as JSON: /api/errors/51888c267888f4c9. Report an issue: GitHub.