## What does this PR do?
Fixes a race condition where multiple threads could attempt to
initialize JavaScriptCore concurrently when the bundler's thread pool
processes files with macros.
Fixes#23540
## How did you verify your code works?
Reproduced the segfault with the Brisa project build and verified the
fix resolves it:
```bash
git clone https://github.com/brisa-build/brisa
cd brisa
bun install
bun run build
```
Before the fix: Segmentation fault with assertion failure
After the fix: Build proceeds without crashing
## Root Cause
The previous implementation used a simple boolean flag `has_loaded_jsc`
without synchronization. When multiple bundler threads tried to execute
macros simultaneously, they could race through the initialization check
before `JSC::initialize()` finished finalizing options on another
thread.
This caused crashes with:
```
ASSERTION FAILED: g_jscConfig.options.allowUnfinalizedAccess || g_jscConfig.options.isFinalized
vendor/WebKit/Source/JavaScriptCore/runtime/Options.h(146) : static OptionsStorage::Bool &JSC::Options::forceTrapAwareStackChecks()
```
## The Fix
Replace the boolean flag with `std::call_once`, which provides:
- Thread-safe initialization
- Guaranteed exactly-once execution
- Proper memory barriers to ensure visibility across threads
The initialization code is now wrapped in a lambda passed to
`std::call_once`, capturing the necessary parameters (`evalMode`,
`envp`, `envc`, `onCrash`).
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
---------
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
Adds `BUN_WATCHER_TRACE` environment variable that logs all file watcher
events to a JSON file for debugging. When set, the watcher appends
detailed event information to the specified file path.
## Motivation
Debugging watch-related issues (especially with `bun --watch` and `bun
--hot`) can be difficult without visibility into what the watcher is
actually seeing. This feature provides detailed trace logs showing
exactly which files are being watched and what events are triggered.
## Implementation
- **Isolated module** (`src/watcher/WatcherTrace.zig`) - All trace logic
in separate file
- **No locking needed** - Watcher runs on its own thread, no mutex
required
- **Append-only mode** - Traces persist across multiple runs for easier
debugging
- **Silent errors** - Won't break functionality if trace file can't be
created
- **JSON format** - Easy to parse and analyze
## Usage
```bash
BUN_WATCHER_TRACE=/tmp/watch.log bun --watch script.js
BUN_WATCHER_TRACE=/tmp/hot.log bun --hot server.ts
```
## JSON Output Format
Each line is a JSON object with:
```json
{
"timestamp": 1760280923269,
"index": 0,
"path": "/path/to/watched/file.js",
"delete": false,
"write": true,
"rename": false,
"metadata": false,
"move_to": false,
"changed_files": ["script.js"]
}
```
## Testing
All tests use stdout streaming to wait for actual reloads (no
sleeps/timeouts):
- Tests with `--watch` flag
- Tests with `fs.watch` API
- Tests that trace file appends across multiple runs
- Tests validation of JSON format and event details
```
✅ 4 pass
❌ 0 fail
📊 52 expect() calls
```
## Files Changed
- `src/Watcher.zig` - Minimal integration with WatcherTrace module
- `src/watcher/WatcherTrace.zig` - New isolated trace implementation
- `src/watcher/KEventWatcher.zig` - Calls writeTraceEvents before
onFileUpdate
- `src/watcher/INotifyWatcher.zig` - Calls writeTraceEvents before
onFileUpdate
- `src/watcher/WindowsWatcher.zig` - Calls writeTraceEvents before
onFileUpdate
- `test/cli/watch/watcher-trace.test.ts` - Comprehensive tests
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
---------
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
This PR implements support for `localAddress` and `localPort` options in
TCP connections, allowing users to bind outgoing connections to a
specific local IP address and port.
This addresses issue #6888 and implements Node.js-compatible behavior
for these options.
## Changes
### C Layer (uSockets)
- **`bsd.c`**: Modified `bsd_create_connect_socket()` to accept a
`local_addr` parameter and call `bind()` before `connect()` when a local
address is specified
- **`context.c`**: Updated `us_socket_context_connect()` and
`start_connections()` to parse and pass local address parameters through
the connection flow
- **`libusockets.h`**: Updated public API signatures to include
`local_host` and `local_port` parameters
- **`internal.h`**: Added `local_host` and `local_port` fields to
`us_connecting_socket_t` structure
- **`openssl.c`**: Updated SSL connection function to match the new
signature
### Zig Layer
- **`SocketContext.zig`**: Updated `connect()` method to accept and pass
through `local_host` and `local_port` parameters
- **`socket.zig`**: Modified `connectAnon()` to handle local address
binding, including IPv6 bracket removal and proper memory management
- **`Handlers.zig`**: Added `localAddress` and `localPort` fields to
`SocketConfig` and implemented parsing from JavaScript options
- **`Listener.zig`**: Updated connection structures to store and pass
local binding information
- **`socket.zig` (bun.js/api/bun)**: Modified `doConnect()` to extract
and pass local address options
- Updated all other call sites (HTTP, MySQL, PostgreSQL, Valkey) to pass
`null, 0` for backward compatibility
### JavaScript Layer
- **`net.ts`**: Enabled `localAddress` and `localPort` support by
passing these options to `doConnect()` and removing TODO comments
### Tests
- **`06888-localaddress.test.ts`**: Added comprehensive tests covering:
- IPv4 local address binding
- IPv4 local address and port binding
- IPv6 local address binding (loopback)
- Backward compatibility (connections without local address)
## Test Results
All tests pass successfully:
```
✓ TCP socket can bind to localAddress - IPv4
✓ TCP socket can bind to localAddress and localPort - IPv4
✓ TCP socket can bind to localAddress - IPv6 loopback
✓ TCP socket without localAddress works normally
4 pass, 0 fail
```
## API Usage
```typescript
import net from "net";
// Connect with a specific local address
const client = net.createConnection({
host: "example.com",
port: 80,
localAddress: "192.168.1.100", // Bind to this local IP
localPort: 0, // Let system assign port (optional)
});
```
## Implementation Details
The implementation follows the same flow as Node.js:
1. JavaScript options are parsed in `Handlers.zig`
2. Local address/port are stored in the connection configuration
3. The Zig layer processes and passes them to the C layer
4. The C layer parses the local address and calls `bind()` before
`connect()`
5. Both IPv4 and IPv6 addresses are supported
Memory management is handled properly throughout the stack, with
appropriate allocation/deallocation at each layer.
Closes#6888🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
### What does this PR do?
Makes sure strings are doubled quoted when they start with flow
indicators and `:`.
Fixes#23502
### How did you verify your code works?
Added tests for each indicator in flow and block context
### What does this PR do?
### How did you verify your code works?
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
### What does this PR do?
Add missing error handling for directory entries errors
The code was missing a check for .err
### How did you verify your code works?
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Fixes#23474
## Summary
When `request.cookies.set()` is called before `server.upgrade()`, the
cookies are now properly included in the WebSocket upgrade response
headers.
## Problem
Previously, cookies set on the request via `req.cookies.set()` were only
written for regular HTTP responses but were ignored during WebSocket
upgrades. Users had to manually pass cookies via the `headers` option:
```js
server.upgrade(req, {
headers: {
"Set-Cookie": `SessionId=${sessionId}`,
},
});
```
## Solution
Modified `src/bun.js/api/server.zig` to check for and write cookies to
the WebSocket upgrade response after the "101 Switching Protocols"
status is set but before the actual upgrade is performed.
The fix handles both cases:
- When `upgrade()` is called without custom headers
- When `upgrade()` is called with custom headers
## Testing
Added comprehensive regression tests in
`test/regression/issue/23474.test.ts` that:
- Verify cookies are set in the upgrade response without custom headers
- Verify cookies are set in the upgrade response with custom headers
- Use `Promise.withResolvers()` for efficient async handling (no
arbitrary timeouts)
Tests confirmed:
- ❌ Fail with system bun v1.2.23 (without fix)
- ✅ Pass with debug build v1.3.0 (with fix)
## Manual verification
```bash
curl -i -H "Connection: Upgrade" -H "Upgrade: websocket" \
-H "Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==" \
-H "Sec-WebSocket-Version: 13" \
http://localhost:3000/ws
```
Response now includes:
```
HTTP/1.1 101 Switching Protocols
Set-Cookie: test=123; Path=/; SameSite=Lax
Upgrade: websocket
Connection: Upgrade
...
```
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
## Summary
Fixes Clang 19 detection in the Nix flake environment by explicitly
setting CMAKE compiler environment variables in the shellHook.
## Problem
When using `nix develop` or `nix print-dev-env`, CMake was unable to
detect the Clang 19 compiler because the `CMAKE_C_COMPILER` and
`CMAKE_CXX_COMPILER` environment variables were not being set, even
though the compiler was available in the environment.
The `shell.nix` file correctly sets these variables (lines 80-87), but
`flake.nix` was missing them.
## Solution
Updated `flake.nix` shellHook to export the same compiler environment
variables as `shell.nix`:
- `CC`, `CXX`, `AR`, `RANLIB`
- `CMAKE_C_COMPILER`, `CMAKE_CXX_COMPILER`, `CMAKE_AR`, `CMAKE_RANLIB`
This ensures consistent compiler detection across both Nix entry points
(`nix develop` with flakes and `nix-shell` with shell.nix).
## Testing
Verified that all compiler variables are now properly set:
```bash
nix develop --accept-flake-config --impure --command bash -c 'echo "CMAKE_C_COMPILER=$CMAKE_C_COMPILER"'
# Output: CMAKE_C_COMPILER=/nix/store/.../clang-wrapper-19.1.7/bin/clang
```
Also tested with the profile workflow:
```bash
nix develop --accept-flake-config --impure --profile ./dev-profile --command true
eval "$(nix print-dev-env ./dev-profile --accept-flake-config --impure)"
echo "CMAKE_C_COMPILER=$CMAKE_C_COMPILER"
# Output: CMAKE_C_COMPILER=/nix/store/.../clang
```
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
## Summary
This PR fixes incorrect WriteBarrier initialization patterns throughout
the Bun codebase where `.set()` or `.setEarlyValue()` was being called
in the constructor body or in `finishCreation()`. According to
JavaScriptCore's `WriteBarrier.h`, WriteBarriers that are initialized
during construction should use the `WriteBarrierEarlyInit` constructor
in the initializer list to avoid triggering unnecessary write barriers.
## Changes
The following classes were updated to properly initialize WriteBarrier
fields:
1. **InternalModuleRegistry** - Initialize internal fields in
constructor using `setWithoutWriteBarrier()` instead of calling `.set()`
in `finishCreation()`
2. **AsyncContextFrame** - Pass callback and context to constructor and
use `WriteBarrierEarlyInit`
3. **JSCommonJSModule** - Pass id, filename, dirname to constructor and
use `WriteBarrierEarlyInit`
4. **JSMockImplementation** - Pass initial values to constructor and use
`WriteBarrierEarlyInit`
5. **JSConnectionsList** - Pass connection sets to constructor and use
`WriteBarrierEarlyInit`
6. **JSBunRequest** - Pass params to constructor and initialize both
`m_params` and `m_cookies` using `WriteBarrierEarlyInit`
7. **JSNodeHTTPServerSocket** - Initialize `currentResponseObject` using
`WriteBarrierEarlyInit` instead of calling `setEarlyValue()`
## Why This Matters
From JavaScriptCore's `WriteBarrier.h`:
```cpp
enum WriteBarrierEarlyInitTag { WriteBarrierEarlyInit };
// Constructor for early initialization during object construction
WriteBarrier(T* value, WriteBarrierEarlyInitTag)
{
this->setWithoutWriteBarrier(value);
}
```
Using `WriteBarrierEarlyInit` during construction:
- Avoids triggering write barriers when they're not needed
- Is the correct pattern for initializing WriteBarriers before the
object is fully constructed
- Aligns with JavaScriptCore best practices
## Testing
- ✅ Full debug build completes successfully
- ✅ Basic functionality tested (CommonJS modules, HTTP requests, Node
HTTP servers)
- ✅ No regressions observed
## Note on generate-classes.ts
The code generator (`generate-classes.ts`) does not need updates because
generated classes intentionally leave WriteBarrier fields (callbacks,
cached fields, values) uninitialized. They start with
default-constructed WriteBarriers and are populated later by Zig code
via setter functions, which is the correct pattern for those fields.
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Fixes test\regression\issue\23316-long-path-spawn.test.ts
The problem was ``await Bun.write(join(deepPath, "test.js"),
`console.log("hello");`);`` was failing because the name was too long,
but it failed before refConcurrently was called and it called
unrefConcurrently after failing. so then when the subprocess spawned it
didn't ref.
---------
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
### What does this PR do?
Fixes `bun -p "process.stderr.write('Hello' +
String.fromCharCode(0xd800))"`.
Also fixes potential index out of bounds if there are many invalid
sequences.
This also affects `TextEncoder`.
### How did you verify your code works?
Added tests for edgecases
---------
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
Provides a Nix flake as an alternative to `scripts/bootstrap.sh` for
setting up the Bun development environment.
## What's included:
- **flake.nix**: Full development environment with all dependencies from
bootstrap.sh
- LLVM 19, CMake 3.30+, Node.js 24, Rust, Go
- Build tools: ninja, ccache, pkg-config, make
- Chromium dependencies for Puppeteer testing
- gdb for core dump debugging
- **shell.nix**: Simple wrapper for `nix-shell` usage
- **cmake/CompilerFlags.cmake**: Nix compatibility fixes
- Disable zstd debug compression (Nix's LLVM not built with zstd)
- Set _FORTIFY_SOURCE=0 for -O0 debug builds
- Downgrade _FORTIFY_SOURCE warning to not error
## Usage:
```bash
nix-shell
export CMAKE_SYSTEM_PROCESSOR=$(uname -m)
bun bd
```
## Verified working:
✅ Successfully compiles Bun debug build
✅ Binary tested: `./build/debug/bun-debug --version` → 1.2.24-debug
✅ All dependencies from bootstrap.sh included
## Advantages:
- Fully isolated (no sudo required)
- 100% reproducible dependency versions
- Fast setup with binary caching
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
### What does this PR do?
Calls `uncork()` after flushing response headers to ensure data is sent
as soon as possible, improving responsiveness.
This behavior still works correctly even without the explicit `uncork()`
call, due to the deferred uncork logic implemented here:
6e3359dd16/packages/bun-uws/src/Loop.h (L57-L64)
A test already covers this scenario in
`test/js/node/test/parallel/test-http-flush-response-headers.js`.
### How did you verify your code works?
CI
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
### What does this PR do?
fix tests failing because of example.com
### How did you verify your code works?
CI
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Fixes#23333, Fixes#13978
### What does this PR do?
### How did you verify your code works?
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: pfg <pfg@pfg.pw>
Co-authored-by: Zack Radisic <zack@theradisic.com>
## What does this PR do?
Bumps Bun version from 1.2.24 to 1.3.0, marking the start of the 1.3.x
release series.
## Changes
- **`package.json`**: Updated version from `1.2.24` to `1.3.0`
- **`LATEST`**: Updated from `1.2.23` to `1.3.0` (used by installation
scripts)
- **`test/bundler/bundler_bun.test.ts`**: Updated version check to
include `1.3.x` so export conditions tests continue to run
## Verification
✅ Debug build successful showing version `1.3.0-debug`
✅ All platforms compile successfully via `bun run zig:check-all` (49/49
steps)
✅ Bundler tests pass with updated version check
## Additional Notes
- CI workflow Bun versions (e.g., `1.2.3`, `1.2.0` in
`.github/workflows/release.yml`) are intentionally left unchanged -
these are pinned versions used to run the release tooling, not the
version being released
- Docker images use `ARG BUN_VERSION` passed at build time and don't
need updates
- The actual release version comes from git tags via `${{
env.BUN_VERSION }}`
---
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
Fixes#23380 - this is a use-case for the `--only` flag that I missed
Adds back the `--only` flag. When running `bun test` on a full test
suite, without this flag it will run only that test in its file, but it
will run all other tests from other files. With this flag, it will not
run things from other files.
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: pfg <pfg@pfg.pw>
## Summary
Modernizes `test/bundler/bundler_promiseall_deadcode.test.ts` to use the
`itBundled` test helper instead of manual temp directory creation and
spawning. This makes the test more concise, maintainable, and consistent
with other bundler tests.
## Changes
- Replace `tempDirWithFiles` + manual `Bun.spawn` with `itBundled`
- Use `files` object for test fixtures instead of creating a temp
directory
- Use `onAfterBundle` callback for bundled output assertions
- Use `run.validate` for runtime stderr validation
- Use `run.partialStdout` for stdout verification
- Preserve all original test assertions and behavior
## Test Results
All 3 tests pass with identical functional behavior:
```
3 pass
0 fail
2 snapshots, 23 expect() calls
Ran 3 tests across 1 file. [8.95s]
```
## Verification
All original assertions are preserved:
- ✅ Build success validation
- ✅ Bundled output snapshots (updated paths to match itBundled format)
- ✅ `__esm` and `__promiseAll` presence/absence checks
- ✅ Runtime execution validation (exit code 0)
- ✅ Runtime stderr validation (no async syntax errors)
- ✅ Runtime stdout validation (contains expected output)
The test is now more concise (407 insertions vs 514 deletions) while
maintaining full test coverage.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
### What does this PR do?
Makes isolated installs the default install strategy for projects with
workspaces in Bun v1.3.
Also fixes creating patches with `bun patch` and `--linker isolated`
Fixes#22693
### How did you verify your code works?
Added tests for node_modules renaming `bun patch` with isolated install.
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Alternative to #15596 where it now only impacts `bun run` for the same
cwd dir. This does not effect `bunx` ([even though according to code it
should load
it](7830e15650/src/cli.zig (L2597-L2628))),
and isnt as fancy as `bun install` where it ensures to check the bunfig
in `package.json` dir.
This shouldn't have any performance issues because its already loading
the file, but now its loading earlier so it can use `run.bun` option.
Fixes#11445, (as well as fixes#15484, fixes#15483, fixes#17064)
---------
Co-authored-by: pfg <pfg@pfg.pw>
## Summary
This PR improves the correctness of bin linking by atomically
normalizing `\r\n` to `\n` in shebang lines when linking bins.
### Changes
- **Refactored shebang normalization in `src/install/bin.zig`**:
- Extracted logic into separate `tryNormalizeShebang` function
- Changed from in-place file modification to atomic file replacement
- Reads entire file, creates temporary file with corrected shebang, then
atomically renames
- Properly cleans up temporary files on errors
- **Added test coverage**:
- New test file `test/cli/install/shebang-normalize.test.ts` verifies
CRLF normalization works correctly
- Modified existing test in `bun-link.test.ts` to use Python script with
CRLF shebang
### Why
The previous implementation modified files in-place by seeking to the
`\r` position and overwriting with `\n`. This could potentially corrupt
files if interrupted mid-write. The new atomic approach ensures file
integrity by writing to a temporary file first, then renaming it to
replace the original.
## Test plan
- ✅ `bun bd test test/cli/install/shebang-normalize.test.ts` - passes
- ✅ Verified bins with CRLF shebangs are normalized to LF during linking
- ✅ Code compiles successfully
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
### What does this PR do?
BeforeOpen code is not necessary since we have `setOnSocketUpgraded`
callback now,and we should NOT convert websocket to a response, make
sure that no closed socket is passed to `JSNodeHTTPServerSocket`, change
isIdle to be inside AsyncSocketData to be more reliable (works for
websocket and normal sockets)
### How did you verify your code works?
CI
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
## Summary
Fixed a race condition where calling `pause()` followed by `resume()` on
`process.stdin` would prevent data from being received, causing the
process to exit immediately instead of listening for input.
## Root Cause
The issue was in the pause/resume event handling logic in
`ProcessObjectInternals.ts`:
1. When `pause()` is called, the "pause" event handler schedules a
`disown()` call for the next tick
2. When `resume()` is called immediately after, it calls `own()` to
acquire a stream reader
3. On the next tick, the scheduled `disown()` from step 1 executes and
incorrectly releases the reader that was just acquired in step 2
This race condition left the stream without a reader, so no data could
be received.
## Solution
Added a `pendingDisown` flag that:
- Gets set to `true` when scheduling a disown operation
- Gets cleared to `false` when `own()` is called (during resume)
- Prevents the scheduled disown from executing if it has been cancelled
by a subsequent `own()` call
## Test Plan
- [x] Added regression tests in
`test/regression/issue/stdin-pause-resume.test.ts`
- [x] Verified fix with original reproduction case
- [x] Existing stdin/tty tests still pass
(`tty-readstream-ref-unref.test.ts`,
`tty-reopen-after-stdin-eof.test.ts`)
## Reproduction
Before this fix, the following code would exit immediately:
```ts
process.stdin.on("data", chunk => {
process.stdout.write(chunk);
});
process.stdin.pause();
process.stdin.resume();
```
After the fix, it correctly waits for and processes input.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
