## Summary
This PR fixes infinite recursion and stack overflow crashes when error
objects have circular references in their properties, particularly when
`error.stack = error`.
### The Problem
When an error object's stack property references itself or creates a
circular reference chain, Bun would enter infinite recursion and crash.
Common patterns that triggered this:
```javascript
const error = new Error();
error.stack = error; // Crash!
console.log(error);
// Or circular cause chains:
error1.cause = error2;
error2.cause = error1; // Crash!
```
### The Solution
Added proper circular reference detection at three levels:
1. **C++ bindings layer** (`bindings.cpp`): Skip processing if `stack`
property equals the error object itself
2. **VirtualMachine layer** (`VirtualMachine.zig`): Track visited errors
when printing error instances and their causes
3. **ConsoleObject layer** (`ConsoleObject.zig`): Properly coordinate
visited map between formatters
Circular references are now safely detected and printed as `[Circular]`
instead of causing crashes.
## Test plan
Added comprehensive tests in
`test/regression/issue/circular-error-stack.test.ts`:
- ✅ `error.stack = error` circular reference
- ✅ Nested circular references via error properties
- ✅ Circular cause chains (`error1.cause = error2; error2.cause =
error1`)
All tests pass:
```
bun test circular-error-stack.test.ts
✓ error with circular stack reference should not cause infinite recursion
✓ error with nested circular references should not cause infinite recursion
✓ error with circular reference in cause chain
```
Manual testing:
```javascript
// Before: Stack overflow crash
// After: Prints error normally
const error = new Error("Test");
error.stack = error;
console.log(error); // error: Test
```
🤖 Generated with [Claude Code](https://claude.ai/code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
## Summary
- Implements proper WebSocket subprotocol negotiation per RFC 6455 and
WHATWG standards
- Adds HeaderValueIterator utility for parsing comma-separated header
values
- Fixes WebSocket client to correctly validate server subprotocol
responses
- Sets WebSocket.protocol property to negotiated subprotocol per WHATWG
spec
- Includes comprehensive test coverage for all subprotocol scenarios
## Changes
**Core Implementation:**
- Add `HeaderValueIterator` utility for parsing comma-separated HTTP
header values
- Replace hash-based protocol matching with proper string set comparison
- Implement WHATWG compliant protocol property setting on successful
negotiation
**WebSocket Client (`WebSocketUpgradeClient.zig`):**
- Parse client subprotocols into StringSet using HeaderValueIterator
- Validate server response against requested protocols
- Set protocol property when server selects a matching subprotocol
- Allow connections when server omits Sec-WebSocket-Protocol header (per
spec)
- Reject connections when server sends unknown or empty subprotocol
values
**C++ Bindings:**
- Add `setProtocol` method to WebSocket class for updating protocol
property
- Export C binding for Zig integration
## Test Plan
Comprehensive test coverage for all subprotocol scenarios:
- ✅ Server omits Sec-WebSocket-Protocol header (connection allowed,
protocol="")
- ✅ Server sends empty Sec-WebSocket-Protocol header (connection
rejected)
- ✅ Server selects valid subprotocol from multiple client options
(protocol set correctly)
- ✅ Server responds with unknown subprotocol (connection rejected with
code 1002)
- ✅ Validates CloseEvent objects don't trigger [Circular] console bugs
All tests use proper WebSocket handshake implementation and validate
both client and server behavior per RFC 6455 requirements.
## Issues Fixed
Fixes#10459 - WebSocket client does not retrieve the protocol sent by
the server
Fixes#10672 - `obs-websocket-js` is not compatible with Bun
Fixes#17707 - Incompatibility with NodeJS when using obs-websocket-js
library
Fixes#19785 - Mismatch client protocol when connecting with multiple
Sec-WebSocket-Protocol
This enables obs-websocket-js and other libraries that rely on proper
RFC 6455 subprotocol negotiation to work correctly with Bun.
🤖 Generated with [Claude Code](https://claude.ai/code)
---------
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
### What does this PR do?
This PR adds builtin YAML parsing with `Bun.YAML.parse`
```js
import { YAML } from "bun";
const items = YAML.parse("- item1");
console.log(items); // [ "item1" ]
```
Also YAML imports work just like JSON and TOML imports
```js
import pkg from "./package.yaml"
console.log({ pkg }); // { pkg: { name: "pkg", version: "1.1.1" } }
```
### How did you verify your code works?
Added some tests for YAML imports and parsed values.
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
