## Summary
- Fixes#26422
- Preserve HTTP header case when sending requests (e.g., `Content-Type`
instead of `content-type`)
- HTTP headers are technically case-insensitive per RFC 7230, but many
APIs expect specific casing
## Test plan
- [x] Added tests that verify headers are sent with proper case on the
wire
- [x] Tests use raw TCP sockets to capture actual HTTP wire format
- [x] Tests fail with system Bun (lowercase headers), pass with fixed
build
🤖 Generated with [Claude Code](https://claude.ai/claude-code)
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
## Summary
Fix a memory leak in `RequestContext.doRenderWithBody()` where
`Strong.Impl` memory was leaked when proxying streaming responses
through Bun's HTTP server.
## Problem
When a streaming response (e.g., from a proxied fetch request) was
forwarded through Bun's server:
1. `response_body_readable_stream_ref` was initialized at line 1836
(from `lock.readable`) or line 1841 (via `Strong.init()`)
2. For `.Bytes` streams with `has_received_last_chunk=false`, a **new**
Strong reference was created at line 1902
3. The old Strong reference was **never deinit'd**, causing
`Strong.Impl` memory to leak
This leak accumulated over time with every streaming response proxied
through the server.
## Solution
Add `this.response_body_readable_stream_ref.deinit()` before creating
the new Strong reference. This is safe because:
- `stream` exists as a stack-local variable
- JSC's conservative GC tracks stack-local JSValues
- No GC can occur between consecutive synchronous Zig statements
- Therefore, `stream` won't be collected between `deinit()` and
`Strong.init()`
## Test
Added `test/js/web/fetch/server-response-stream-leak.test.ts` which:
- Creates a backend server that returns delayed streaming responses
- Creates a proxy server that forwards the streaming responses
- Makes 200 requests and checks that ReadableStream objects don't
accumulate
- Fails on system Bun v1.3.5 (202 leaked), passes with the fix
## Related
Similar to the Strong reference leak fixes in:
- #23313 (fetch memory leak)
- #25846 (fetch cyclic reference leak)
### What does this PR do?
remove agent in global WebSocket (in node.js it uses dispatcher not
agent) add agent support in ws module (this actually uses agent)
### How did you verify your code works?
Tests
## Summary
This PR fixes a memory leak that occurs when `fetch()` is called with a
`ReadableStream` body. The ReadableStream objects were not being
properly released, causing them to accumulate in memory.
## Problem
When using `fetch()` with a ReadableStream body:
```javascript
const stream = new ReadableStream({
start(controller) {
controller.enqueue(new TextEncoder().encode("data"));
controller.close();
}
});
await fetch(url, { method: "POST", body: stream });
```
The ReadableStream objects leak because `FetchTasklet.clearData()` has a
conditional that prevents `detach()` from being called on ReadableStream
request bodies after streaming has started.
### Root Cause
The problematic condition in `clearData()`:
```zig
if (this.request_body != .ReadableStream or this.is_waiting_request_stream_start) {
this.request_body.detach();
}
```
After `startRequestStream()` is called:
- `is_waiting_request_stream_start` becomes `false`
- `request_body` is still `.ReadableStream`
- The condition evaluates to `(false or false) = false`
- `detach()` is skipped → **memory leak**
### Why the Original Code Was Wrong
The original code appears to assume that when `startRequestStream()` is
called, ownership of the Strong reference is transferred to
`ResumableSink`. However, this is incorrect:
1. `startRequestStream()` creates a **new independent** Strong reference
in `ResumableSink` (see `ResumableSink.zig:119`)
2. The FetchTasklet's original reference is **not transferred** - it
becomes redundant
3. Strong references in Bun are independent - calling `deinit()` on one
does not affect the other
## Solution
Remove the conditional and always call `detach()`:
```zig
// Always detach request_body regardless of type.
// When request_body is a ReadableStream, startRequestStream() creates
// an independent Strong reference in ResumableSink, so FetchTasklet's
// reference becomes redundant and must be released to avoid leaks.
this.request_body.detach();
```
### Safety Analysis
This change is safe because:
1. **Strong references are independent**: Each Strong reference
maintains its own ref count. Detaching FetchTasklet's reference doesn't
affect ResumableSink's reference
2. **Idempotency**: `detach()` is safe to call on already-detached
references
3. **Timing**: `clearData()` is only called from `deinit()` after
streaming has completed (ref_count = 0)
4. **No UAF risk**: `deinit()` only runs when ref_count reaches 0, which
means all streaming operations have completed
## Test Results
Before fix (with system Bun):
```
Expected: <= 100
Received: 501 (Request objects leaked)
Received: 1002 (ReadableStream objects leaked)
```
After fix:
```
6 pass
0 fail
```
## Test Coverage
Added comprehensive tests in
`test/js/web/fetch/fetch-cyclic-reference.test.ts` covering:
- Response stream leaks with cyclic references
- Streaming response body leaks
- Request body stream leaks with cyclic references
- ReadableStream body leaks (no cyclic reference needed to reproduce)
- Concurrent fetch operations with cyclic references
---------
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
## Summary
- Add maximum decompressed message size limit to WebSocket client
deflate handling
- Add test coverage for decompression limits
## Test plan
- Run `bun test
test/js/web/websocket/websocket-permessage-deflate-edge-cases.test.ts`
🤖 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
- Fix bug where `Response.clone()` would lock the original response's
body when `response.body` was accessed before cloning
- Apply the same fix to `Request.clone()`
## Root Cause
When `response.body` was accessed before calling `response.clone()`, the
original response's body would become locked after cloning. This
happened because:
1. When the cloned response was wrapped with `toJS()`,
`checkBodyStreamRef()` was called which moved the stream from
`Locked.readable` to `js.gc.stream` and cleared `Locked.readable`
2. The subsequent code tried to get the stream from `Locked.readable`,
which was now empty, so the body cache update was skipped
3. The JavaScript-level body property cache still held the old locked
stream
## Fix
Updated the cache update logic to:
1. For the cloned response: use `js.gc.stream.get()` instead of
`Locked.readable.get()` since `toJS()` already moved the stream
2. For the original response: use `Locked.readable.get()` which still
holds the teed stream since `checkBodyStreamRef` hasn't been called yet
## Reproduction
```javascript
const readableStream = new ReadableStream({
start(controller) {
controller.enqueue(new TextEncoder().encode("Hello, world!"));
controller.close();
},
});
const response = new Response(readableStream);
console.log(response.body?.locked); // Accessing body before clone
const cloned = response.clone();
console.log(response.body?.locked); // Expected: false, Actual: true ❌
console.log(cloned.body?.locked); // Expected: false, Actual: false ✅
```
## Test plan
- [x] Added regression tests for `Response.clone()` in
`test/js/web/fetch/response.test.ts`
- [x] Added regression test for `Request.clone()` in
`test/js/web/request/request.test.ts`
- [x] Verified tests fail with system bun (before fix) and pass with
debug build (after fix)
🤖 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?
- removes the `Unimplemented in Bun` comment on `CompressionStream` and
`DecompressionStream`
- updates the types for `CompressionStream` and `DecompressionStream` to
add a new internal `CompressionFormat` type to the constructor, which
adds `brotli` and `zstd` to the union
- adds tests for brotli and zstd usage
- adds lib.dom.d.ts exclusions for brotli and zstd as these don't exist
in the DOM version of CompressionFormat
fixes#25367
### How did you verify your code works?
typechecks and tests
### What does this PR do?
Fixes checking for exceptions when creating empty or used readable
streams
also fixes ENG-24038
### How did you verify your code works?
Added a test for creating empty streams
## Summary
- Implements the `%j` format specifier for `console.log` and related
console methods
- `%j` outputs the JSON stringified representation of the value
- Previously, `%j` was not recognized and was left as literal text in
the output
## Test plan
- [x] Run `bun bd test test/regression/issue/24234.test.ts` - all 5
tests pass
- [x] Verify tests fail with system Bun (`USE_SYSTEM_BUN=1`) to confirm
fix validity
- [x] Manual verification: `console.log('%j', {foo: 'bar'})` outputs
`{"foo":"bar"}`
## Example
Before (bug):
```
$ bun -e "console.log('%j %s', {foo: 'bar'}, 'hello')"
%j [object Object] hello
```
After (fixed):
```
$ bun -e "console.log('%j %s', {foo: 'bar'}, 'hello')"
{"foo":"bar"} hello
```
Closes#24234🤖 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
Implements the [URLPattern Web
API](https://developer.mozilla.org/en-US/docs/Web/API/URLPattern) based
on WebKit's implementation. URLPattern provides declarative pattern
matching for URLs, similar to how regular expressions work for strings.
### Features
- **Constructor**: Create patterns from strings or `URLPatternInit`
dictionaries
- **`test()`**: Check if a URL matches the pattern (returns boolean)
- **`exec()`**: Extract matched groups from a URL (returns
`URLPatternResult` or null)
- **Pattern properties**: `protocol`, `username`, `password`,
`hostname`, `port`, `pathname`, `search`, `hash`
- **`hasRegExpGroups`**: Detect if the pattern uses custom regular
expressions
### Example Usage
```js
// Match URLs with a user ID parameter
const pattern = new URLPattern({ pathname: '/users/:id' });
pattern.test('https://example.com/users/123'); // true
pattern.test('https://example.com/posts/456'); // false
const result = pattern.exec('https://example.com/users/123');
console.log(result.pathname.groups.id); // "123"
// Wildcard matching
const filesPattern = new URLPattern({ pathname: '/files/*' });
const match = filesPattern.exec('https://example.com/files/image.png');
console.log(match.pathname.groups[0]); // "image.png"
```
## Implementation Notes
- Adapted from WebKit's URLPattern implementation
- Modified JS bindings to work with Bun's infrastructure (simpler
`convertDictionary` patterns, WTF::Variant handling)
- Added IsoSubspaces for proper GC integration
## Test Plan
- [x] 408 tests from Web Platform Tests pass
- [x] Tests fail with system Bun (URLPattern not defined), pass with
debug build
- [x] Manual testing of basic functionality
Fixes https://github.com/oven-sh/bun/issues/2286🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
## Summary
- Fix crash in `FormData.from()` when called with very large ArrayBuffer
input
- Add length check in C++ `toString` function against both Bun's
synthetic limit and WebKit's `String::MaxLength`
- For UTF-8 tagged strings, use simdutf to calculate actual UTF-16
length only when byte length exceeds the limit
## Root Cause
When `FormData.from()` was called with a very large ArrayBuffer (e.g.,
`new Uint32Array(913148244)` = ~3.6GB), the code would crash with:
```
ASSERTION FAILED: data.size() <= MaxLength
vendor/WebKit/Source/WTF/wtf/text/StringImpl.h(886)
```
The `toString()` function in `helpers.h` was only checking against
`Bun__stringSyntheticAllocationLimit` (which defaults to ~4GB), but not
against WebKit's `String::MaxLength` (INT32_MAX, ~2GB). When the input
exceeded `String::MaxLength`, `createWithoutCopying()` would fail with
an assertion.
## Changes
1. **helpers.h**: Added `|| str.len > WTF::String::MaxLength` checks to
all three code paths in `toString()`:
- UTF-8 tagged pointer path (with simdutf length calculation only when
needed)
- External pointer path
- Non-copying creation path
2. **url.zig**: Reverted the incorrect Zig-side check (UTF-8 byte length
!= UTF-16 character length)
## Test plan
- [x] Added test that verifies FormData.from with oversized input
doesn't crash
- [x] Verified original crash case now returns empty FormData instead of
crashing:
```js
const v3 = new Uint32Array(913148244);
FormData.from(v3); // No longer crashes
```
🤖 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?
`blob.stream(undefined)`
### How did you verify your code works?
Added a test
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Should fix https://github.com/oven-sh/bun/issues/24104
### What does this PR do?
This PR is changing `ERR_BODY_ALREADY_USED` to be TypeError instead of
Error.
### How did you verify your code works?
A test case added to verify that request call correctly throws a
TypeError after another request call on the same Request, confirming the
fix addresses the issue.
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
### What does this PR do?
Previously, `JSC__JSPromise__wrap` would call
`JSC::JSPromise::resolvedPromise(globalObject, result)` without checking
if an exception was thrown during promise resolution. This
could happen in certain edge cases, such as when the result value is a
thenable that triggers stack overflow, or when the promise resolution
mechanism itself encounters an error.
When such exceptions occurred, they would escape back to the Zig code,
causing the CatchScope assertion to fail with "ASSERTION FAILED:
Unexpected exception observed on thread"
instead of being properly handled.
This PR adds an exception check immediately after calling
`JSC::JSPromise::resolvedPromise()` and before the `RELEASE_AND_RETURN`
macro. If an exception is detected, the function
now clears it and returns a rejected promise with the exception value,
ensuring consistent error handling behavior. This matches the pattern
already used earlier in the function
for the initial function call exception handling.
### How did you verify your code works?
new and existing tests
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
### What does this PR do?
When `process.nextTick` is overwritten, segv will be occured via
internal `processTick` call.
This patch fixes it.
### How did you verify your code works?
Tests.
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
### What does this PR do?
Adds missing exception check for ReadableStream.
### How did you verify your code works?
Tests
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
## Summary
Fixes a panic that occurred when a WebSocket close frame's payload was
split across multiple TCP packets.
## The Bug
The panic occurred at `websocket_client.zig:681`:
```
panic: index out of bounds: index 24, len 14
```
This happened when:
- A close frame had a payload of 24 bytes (2 byte code + 22 byte reason)
- The first TCP packet contained 14 bytes (header + partial payload)
- The code tried to access `data[2..24]` causing the panic
## Root Causes
1. **Bounds checking issue**: The code assumed all close frame data
would arrive in one packet and tried to `@memcpy` without verifying
sufficient data was available.
2. **Premature flag setting**: `close_received = true` was set
immediately upon entering the close state. This prevented `handleData`
from being called again when the remaining bytes arrived (early return
at line 354).
## The Fix
Implemented proper fragmentation handling for close frames, following
the same pattern used for ping frames:
- Added `close_frame_buffering` flag to track buffering state
- Buffer incoming data incrementally using the existing
`ping_frame_bytes` buffer
- Track total expected length and bytes received so far
- Only set `close_received = true` after all bytes are received
- Wait for more data if the frame is incomplete
## Testing
- Created two regression tests that fragment close frames across
multiple packets
- All existing WebSocket tests pass (`test/js/web/websocket/`)
- Verified the original panic no longer occurs
## Related
This appears to be the root cause of crashes reported on Windows when
WebSocket connections close, particularly when close frames have reasons
that get fragmented by the network stack.
---
🤖 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>
## Summary
Fixes an assertion failure that occurred when `URLSearchParams.toJSON()`
was called with numeric string keys.
## The Problem
When using numeric string keys (e.g., `"39208"`, `"0"`, `"100"`),
calling `toJSON()` would trigger:
```
ASSERTION FAILED: !parseIndex(propertyName)
cache/webkit-6d0f3aac0b817cc0/include/JavaScriptCore/JSObjectInlines.h:444
```
Reproduction:
```javascript
const params = new URLSearchParams();
params.set("39208", "updated");
params.toJSON(); // crashes
```
## Root Cause
The `getInternalProperties` function in `JSURLSearchParams.cpp` was
using `putDirect()` to add properties to the result object. However,
`putDirect()` cannot be used with property names that can be parsed as
array indices - JSC expects such properties to use indexed storage
instead.
## The Fix
- Replace `putDirect()` with `putDirectMayBeIndex()`, which
automatically handles both regular properties and numeric indices
- Replace `getDirect()` with `get()` to properly retrieve values for
both types of properties
## Test Plan
Added comprehensive tests to `test/js/web/html/URLSearchParams.test.ts`:
- ✅ Single numeric string keys
- ✅ Multiple numeric keys
- ✅ Mixed numeric and non-numeric keys
- ✅ Duplicate numeric keys
- ✅ Extra arguments (original crash case)
All tests pass, and the original crash no longer occurs.
🤖 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?
reduce memory usage when streaming (this should be a temporary solution
until owned_and_done is fixed)
### How did you verify your code works?
Added a test that should not be flaky in CI
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.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>
### 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>
### What does this PR do?
When we added "happy eyeballs" support to fetch(), it meant that
`onOpen` would not be called potentially for awhile. If the AbortSignal
is aborted between `connect()` and the socket becoming
readable/writable, then we would delay closing the connection until the
connection opens. Fixing that fixes#18536.
Separately, the `isHTTPS()` function used in abort and in request body
streams was not thread safe. This caused a crash when many redirects
happen simultaneously while either AbortSignal or request body messages
are in-flight.
This PR fixes https://github.com/oven-sh/bun/issues/14137
### How did you verify your code works?
There are tests
---------
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: Ciro Spaciari <ciro.spaciari@gmail.com>
### 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>
# bun test
Fixes#8768, Fixes#14624, Fixes#20100, Fixes#19875, Fixes#14135,
Fixes#20980, Fixes#21830, Fixes#5738, Fixes#19758, Fixes#12782,
Fixes#5585, Fixes#9548, Might fix 5996
# New features:
## Concurrent tests
Concurrent tests allow running multiple async tests at the same time.
```ts
// concurrent.test.ts
test.concurrent("this takes a while 1", async () => {
await Bun.sleep(1000);
});
test.concurrent("this takes a while 2", async () => {
await Bun.sleep(1000);
});
test.concurrent("this takes a while 3", async () => {
await Bun.sleep(1000);
});
```
Without `.concurrent`, this test file takes 3 seconds to run because
each one has to wait for the one before it to finish before it can
start.
With `.concurrent`, this file takes 1 second because all three sleeps
can run at once.
```
$> bun-after test concurrent
concurrent.test.js:
✓ this takes a while 1 [1005.36ms]
✓ this takes a while 2 [1012.51ms]
✓ this takes a while 3 [1013.15ms]
3 pass
0 fail
Ran 3 tests across 1 file. [1081.00ms]
```
To run all tests as concurrent, pass the `--concurrent` flag when
running tests.
Limitations:
- concurrent tests cannot attribute `expect()` call counts to the test,
meaning `expect.assertions()` does not function
- concurrent tests cannot use `toMatchSnapshot`. `toMatchInlineSnapshot`
is still supported.
- `beforeAll`/`afterAll` will never be executed concurrently.
`beforeEach`/`afterEach` will.
## Chaining
Chaining multiple describe/test qualifiers is now allowed. Previously,
it would fail.
```ts
// chaining-test-qualifiers.test.ts
test.failing.each([1, 2, 3])("each %i", async i => {
throw new Error(i);
});
```
```
$> bun-after test chaining-test-qualifiers
a.test.js:
✓ each 1
✓ each 2
✓ each 3
```
# Breaking changes:
## Describe ordering
Previously, describe callbacks were called immediately. Now, they are
deferred until the outer callback has finished running. The previous
order matched Jest. The new order is similar to Vitest, but does not
match exactly.
```ts
// describe-ordering.test.ts
describe("outer", () => {
console.log("outer before");
describe("inner", () => {
console.log("inner");
});
console.log("outer after");
});
```
Before, this would print
```
$> bun-before test describe-ordering
outer before
inner
outer after
```
Now, this will print
```
$> bun-after test describe-ordering
outer before
outer after
inner
```
## Test ordering
Describes are no longer always called before tests. They are now in
order.
```ts
// test-ordering.test.ts
test("one", () => {});
describe("scope", () => {
test("two", () => {});
});
test("three", () => {});
```
Before, this would print
```
$> bun-before test test-ordering
✓ scope > two
✓ one
✓ three
```
Now, this will print
```
$> bun-after test test-ordering
✓ one
✓ scope > two
✓ three
```
## Preload hooks
Previously, beforeAll in a preload ran before the first file and
afterAll ran after the last file. Now, beforeAll will run at the start
of each file and afterAll will run at the end of each file. This
behaviour matches Jest and Vitest.
```ts
// preload.ts
beforeAll(() => console.log("preload: beforeAll"));
afterAll(() => console.log("preload: afterAll"));
```
```ts
// preload-ordering-1.test.ts
test("demonstration file 1", () => {});
```
```ts
// preload-ordering-2.test.ts
test("demonstration file 2", () => {});
```
```
$> bun-before test --preload=./preload preload-ordering
preload-ordering-1.test.ts:
preload: beforeAll
✓ demonstration file 1
preload-ordering-2.test.ts:
✓ demonstration file 2
preload: afterAll
```
```
$> bun-after test --preload=./preload preload-ordering
preload-ordering-1.test.ts:
preload: beforeAll
✓ demonstration file 1
preload: afterAll
preload-ordering-2.test.ts:
preload: beforeAll
✓ demonstration file 2
preload: afterAll
```
## Describe failures
Current behaviour is that when an error is thrown inside a describe
callback, none of the tests declared there will run. Now, describes
declared inside will also not run. The new behaviour matches the
behaviour of Jest and Vitest.
```ts
// describe-failures.test.ts
describe("erroring describe", () => {
test("this test does not run because its describe failed", () => {
expect(true).toBe(true);
});
describe("inner describe", () => {
console.log("does the inner describe callback get called?");
test("does the inner test run?", () => {
expect(true).toBe(true);
});
});
throw new Error("uh oh!");
});
```
Before, the inner describe callback would be called and the inner test
would run, although the outer test would not:
```
$> bun-before test describe-failures
describe-failures.test.ts:
does the inner describe callback get called?
# Unhandled error between tests
-------------------------------
11 | throw new Error("uh oh!");
^
error: uh oh!
-------------------------------
✓ erroring describe > inner describe > does the inner test run?
1 pass
0 fail
1 error
1 expect() calls
Ran 1 test across 1 file.
Exited with code [1]
```
Now, the inner describe callback is not called at all.
```
$> bun-after test describe-failures
describe-failures.test.ts:
# Unhandled error between tests
-------------------------------
11 | throw new Error("uh oh!");
^
error: uh oh!
-------------------------------
0 pass
0 fail
1 error
Ran 0 tests across 1 file.
Exited with code [1]
```
## Hook failures
Previously, a beforeAll failure would skip subsequent beforeAll()s, the
test, and the afterAll. Now, a beforeAll failure skips any subsequent
beforeAll()s and the test, but not the afterAll.
```js
beforeAll(() => {
throw new Error("before all: uh oh!");
});
test("my test", () => {
console.log("my test");
});
afterAll(() => console.log("after all"));
```
```
$> bun-before test hook-failures
Error: before all: uh oh!
$> bun-after test hook-failures
Error: before all: uh oh!
after all
```
Previously, an async beforeEach failure would still allow the test to
run. Now, an async beforeEach failure will prevent the test from running
```js
beforeEach(() => {
await 0;
throw "uh oh!";
});
it("the test", async () => {
console.log("does the test run?");
});
```
```
$> bun-before test async-beforeeach-failure
does the test run?
error: uh oh!
uh oh!
✗ the test
$> bun-after test async-beforeeach-failure
error: uh oh!
uh oh!
✗ the test
```
## Hook timeouts
Hooks will now time out, and can have their timeout configured in an
options parameter
```js
beforeAll(async () => {
await Bun.sleep(1000);
}, 500);
test("my test", () => {
console.log("ran my test");
});
```
```
$> bun-before test hook-timeouts
ran my test
Ran 1 test across 1 file. [1011.00ms]
$> bun-after test hook-timeouts
✗ my test [501.15ms]
^ a beforeEach/afterEach hook timed out for this test.
```
## Hook execution order
beforeAll will now execute before the tests in the scope, rather than
immediately when it is called.
```ts
describe("d1", () => {
beforeAll(() => {
console.log("<d1>");
});
test("test", () => {
console.log(" test");
});
afterAll(() => {
console.log("</d1>");
});
});
describe("d2", () => {
beforeAll(() => {
console.log("<d2>");
});
test("test", () => {
console.log(" test");
});
afterAll(() => {
console.log("</d2>");
});
});
```
```
$> bun-before test ./beforeall-ordering.test.ts
<d1>
<d2>
test
</d1>
test
</d2>
$> bun-after test ./beforeall-ordering.test.ts
<d1>
test
</d1>
<d2>
test
</d2>
```
## test inside test
test() inside test() now errors rather than silently failing. Support
for this may be added in the future.
```ts
test("outer", () => {
console.log("outer");
test("inner", () => {
console.log("inner");
});
});
```
```
$> bun-before test
outer
✓ outer [0.06ms]
1 pass
0 fail
Ran 1 test across 1 file. [8.00ms]
$> bun-after test
outer
1 | test("outer", () => {
2 | console.log("outer");
3 | test("inner", () => {
^
error: Cannot call test() inside a test. Call it inside describe() instead.
✗ outer [0.71ms]
0 pass
1 fail
```
## afterAll inside test
afterAll inside a test is no longer allowed
```ts
test("test 1", () => {
afterAll(() => console.log("afterAll"));
console.log("test 1");
});
test("test 2", () => {
console.log("test 2");
});
```
```
$> bun-before
test 1
✓ test 1 [0.05ms]
test 2
✓ test 2
afterAll
$> bun-after
error: Cannot call afterAll() inside a test. Call it inside describe() instead.
✗ test 1 [1.00ms]
test 2
✓ test 2 [0.20ms]
```
# Only inside only
Previously, an outer 'describe.only' would run all tests inside it even
if there was an inner 'test.only'. Now, only the innermost only tests
are executed.
```ts
describe.only("outer", () => {
test("one", () => console.log("should not run"));
test.only("two", () => console.log("should run"));
});
```
```
$> bun-before test
should not run
should run
$> bun-after test
should run
```
With no inner only, the outer only will still run all tests:
```ts
describe.only("outer", () => {
test("test 1", () => console.log("test 1 runs"));
test("test 2", () => console.log("test 2 runs"));
});
```
# Potential follow-up work
- [ ] for concurrent tests, display headers before console.log messages
saying which test it is for
- this will need async context or similar
- refActiveExecutionEntry should also be able to know the current test
even in test.concurrent
- [ ] `test("rerun me", () => { console.log("run one time!"); });`
`--rerun-each=3` <- this runs the first and third time but not the
second time. fix.
- [ ] should to cache the JSValue created from
DoneCallback.callAsFunction
- [ ] implement retry and rerun params for tests.
- [ ] Remove finalizer on ScopeFunctions.zig by storing the data in 3
jsvalues passed in bind rather than using a custom class. We should also
migrate off of the ClassGenerator for ScopeFunctions
- [ ] support concurrent limit, how many concurrent tests are allowed to
run at a time. ie `--concurrent-limit=25`
- [ ] flag to run tests in random order
- [ ] `test.failing` should have its own style in the same way
`test.todo` passing marks as 'todo' insetead of 'passing'. right now
it's `✓` which is confusing.
- [ ] remove all instances of bun.jsc.Jest.Jest.current
- [ ] test options should be in BunTestRoot
- [ ] we will need one global still, stored in the globalobject/vm/?.
but it should not be a Jest instance.
- [ ] consider allowing test() inside test(), as well as afterEach and
afterAll. could even allow describe() too. to do this we would switch
from indices to pointers and they would be in a linked list. they would
be allocated in memorypools for perf/locality. some special
consideration is needed for making sure repeated tests lose their
temporary items. this could also improve memory usage soomewhat.
- [ ] consider using a jsc Bound Function rather than CallbackWithArgs.
bound functions allow adding arguments and they are only one value for
GC instead of many. and this removes our unnecessary three copies.
- [ ] eliminate Strong.Safe. we should be using a C++ class instead.
- [ ] consider modifying the junit reporter to print the whole describe
tree at the end instead of trying to output as test results come in. and
move it into its own file.
- [ ] expect_call_count/expect_assertions is confusing. rename to
`expect_calls`, `assert_expect_calls`. or something.
- [ ] Should make line_no be an enum with a none option and a function
to get if line nombers are enabled
- [ ] looks like we don't need to use file_id anymore (remove
`bun.jsc.Jest.Jest.runner.?.getOrPutFile(file_path).file_id;`, store the
file path directly)
- [ ] 'dot' test reporter like vitest?
- [ ] `test.failing.if(false)` errors because it can't replace mode
'failing' with mode 'skip'. this should probably be allowed instead.
- [ ] trigger timeout termination exception for `while(true) {}`
- [ ] clean up unused callbacks. as soon as we advance to the next
execution group, we can fully clean out the previous one. sometimes
within an execution sequence we can do the same.
- clean by swapping held values with undefined
- [ ] structure cache for performance for donecallback/scopefunctions
- [ ] consider migrating CallbackWithArgs to be a bound function. the
length of the bound function can exclude the specified args.
- [ ] setting both result and maybe_skip is not ideal, maybe there
should be a function to do both at once?
- [ ] try using a linked list rather than arraylist for describe/test
children, see how it affects performance
- [ ] consider a memory pool for describescope/executionentry. test if
it improves performance.
- [ ] consider making RefDataValue methods return the reason for failure
rather than ?value. that way we can improve error messages. the reason
could be a string or it could be a defined error set
- [ ] instead of 'description orelse (unnamed)', let's have description
default to 'unnamed' and not free it if it === the global that defines
that
- [ ] Add a phase before ordering results that inherits properties to
the parents. (eg inherit only from the child and inherit has_callback
from the child. and has_callback can be on describe/test individually
rather than on base). then we won't have that happening in an init()
function (terrible!)
- [ ] this test was incidentally passing because resolves.pass() wasn't
waiting for promise
```
test("fetching with Request object - issue #1527", async () => {
const server = createServer((req, res) => {
res.end();
}).listen(0);
try {
await once(server, "listening");
const body = JSON.stringify({ foo: "bar" });
const request = new Request(`http://localhost:${server.address().port}`,
{
method: "POST",
body,
});
expect(fetch(request)).resolves.pass();
} finally {
server.closeAllConnections();
}
});
```
- [ ] the error "expect.assertions() is not supported in the describe
phase, in concurrent tests, between tests, or after test execution has
completed" is not very good. we should be able to identify which of
those it is and print the right error for the context
- [ ] consider: instead of storing weak pointers to BunTest, we can
instead give the instance an id and check that it is correct when
getting the current bun test instance from the ref
- [ ] auto_killer: add three layers of auto_killer:
- preload (includes file & test)
- file (includes test)
- test
- that way at the end of the test, we kill the test processes. at the
end of the file, we kill the file processes. at the end of all, we kill
anything remaining.
AsyncLocalStorage
- store active_id & refdatavalue. active_id is a replacement for the
above weak pointers thing. refdatavalue is for determining which test it
is. this probably fits in 2×u64
- use for auto_killer so timeouts can kill even in concurrent tests
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
## Summary
This PR migrates all Docker container usage in tests from individual
`docker run` commands to a centralized Docker Compose setup. This makes
tests run **10x faster**, eliminates port conflicts, and provides a much
better developer experience.
## What is Docker Compose?
Docker Compose is a tool for defining and running multi-container Docker
applications. Instead of each test file managing its own containers with
complex `docker run` commands, we define all services once in a YAML
file and Docker Compose handles the orchestration.
## The Problem (Before)
```javascript
// Each test file managed its own container
const container = await Bun.spawn({
cmd: ["docker", "run", "-d", "-p", "0:5432", "postgres:15"],
// ... complex setup
});
```
**Issues:**
- Each test started its own container (30+ seconds for PostgreSQL tests)
- Containers were killed after each test (wasteful!)
- Random port conflicts between tests
- No coordination between test suites
- Docker configuration scattered across dozens of test files
## The Solution (After)
```javascript
// All tests share managed containers
const pg = await dockerCompose.ensure("postgres_plain");
// Container starts only if needed, returns connection info
```
**Benefits:**
- Containers start once and stay running (3 seconds for PostgreSQL tests
- **10x faster!**)
- Automatic port management (no conflicts)
- All services defined in one place
- Lazy loading (services only start when needed)
- Same setup locally and in CI
## What Changed
### New Infrastructure
- `test/docker/docker-compose.yml` - Defines all test services
- `test/docker/index.ts` - TypeScript API for managing services
- `test/docker/README.md` - Comprehensive documentation
- Configuration files and init scripts for services
### Services Migrated
| Service | Status | Tests |
|---------|--------|--------|
| PostgreSQL (plain, TLS, auth) | ✅ | All passing |
| MySQL (plain, native_password, TLS) | ✅ | All passing |
| S3/MinIO | ✅ | 276 passing |
| Redis/Valkey | ✅ | 25/26 passing* |
| Autobahn WebSocket | ✅ | 517 available |
*One Redis test was already broken before migration (reconnection test
times out)
### Key Features
- **Dynamic Ports**: Docker assigns available ports automatically (no
conflicts!)
- **Unix Sockets**: Proxy support for PostgreSQL and Redis Unix domain
sockets
- **Persistent Data**: Volumes for services that need data to survive
restarts
- **Health Checks**: Proper readiness detection for all services
- **Backward Compatible**: Fallback to old Docker method if needed
## Performance Improvements
| Test Suite | Before | After | Improvement |
|------------|--------|-------|-------------|
| PostgreSQL | ~30s | ~3s | **10x faster** |
| MySQL | ~25s | ~3s | **8x faster** |
| Redis | ~20s | ~2s | **10x faster** |
The improvements come from container reuse - containers start once and
stay running instead of starting/stopping for each test.
## How to Use
```typescript
import * as dockerCompose from "../../docker/index.ts";
test("database test", async () => {
// Ensure service is running (starts if needed)
const pg = await dockerCompose.ensure("postgres_plain");
// Connect using provided info
const client = new PostgresClient({
host: pg.host,
port: pg.ports[5432], // Mapped to random available port
});
});
```
## Testing
All affected test suites have been run and verified:
- `bun test test/js/sql/sql.test.ts` ✅
- `bun test test/js/sql/sql-mysql*.test.ts` ✅
- `bun test test/js/bun/s3/s3.test.ts` ✅
- `bun test test/js/valkey/valkey.test.ts` ✅
- `bun test test/js/web/websocket/autobahn.test.ts` ✅
## Documentation
Comprehensive documentation added in `test/docker/README.md` including:
- Detailed explanation of Docker Compose for beginners
- Architecture overview
- Usage examples
- Debugging guide
- Migration guide for adding new services
## Notes
- The Redis reconnection test that's skipped was already broken before
this migration. It's a pre-existing issue with the Redis client's
reconnection logic, not related to Docker changes.
- All tests that were passing before continue to pass after migration.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
---------
Co-authored-by: Claude <claude@anthropic.ai>
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>
tests not in `test/no-validate-leaksan.txt` will run with leaksanitizer
in CI
leaks documented in `test/leaksan.supp` will not cause a test failure
-- notes about leaksanitizer
- will not catch garbage collected objects accumulated during
long-running processes
- will not catch js objects (eg a strong held to a promise)
- will catch native calls to `malloc` not `free`d
- will catch allocations made in C, Zig, C++, libc, dependencies,
dlopen'd
---------
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
## Summary
Adds support for overriding special WebSocket headers (`Host`,
`Sec-WebSocket-Key`, and `Sec-WebSocket-Protocol`) via the headers
option when creating a WebSocket connection.
## Changes
- Modified `WebSocketUpgradeClient.zig` to check for and use
user-provided special headers
- Added header value validation to prevent CRLF injection attacks
- Updated the NonUTF8Headers struct to automatically filter duplicate
headers
- When a custom `Sec-WebSocket-Protocol` header is provided, it properly
updates the subprotocols list for validation
## Implementation Details
The implementation adds minimal code by:
1. Using the existing `NonUTF8Headers` struct's methods to find valid
header overrides
2. Automatically filtering out WebSocket-specific headers in the format
method to prevent duplication
3. Maintaining a single, clean code path in `buildRequestBody()`
## Testing
Added comprehensive tests in `websocket-custom-headers.test.ts` that
verify:
- Custom Host header support
- Custom Sec-WebSocket-Key header support
- Custom Sec-WebSocket-Protocol header support
- Header override behavior when both protocols array and header are
provided
- CRLF injection prevention
- Protection of system headers (Connection, Upgrade, etc.)
- Support for additional custom headers
All existing WebSocket tests continue to pass, ensuring backward
compatibility.
## Security
The implementation includes validation to:
- Reject header values with control characters (preventing CRLF
injection)
- Prevent users from overriding critical system headers like Connection
and Upgrade
- Validate header values according to RFC 7230 specifications
## Use Cases
This feature enables:
- Testing WebSocket servers with specific header requirements
- Connecting through proxies that require custom Host headers
- Implementing custom WebSocket subprotocol negotiation
- Debugging WebSocket connections with specific keys
Fixes #[issue_number]
---------
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>
### What does this PR do?
Allow upgrade to websockets using fetch
This will avoid hanging in http.request and is a step necessary to
implement the upgrade event in the node:http client.
Changes in node:http need to be made in another PR to support 'upgrade'
event (see https://github.com/oven-sh/bun/pull/22412)
### How did you verify your code works?
Test
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
## Summary
Fixes#18413 - Empty chunked gzip responses were causing `Decompression
error: ShortRead`
## The Issue
When a server sends an empty response with `Content-Encoding: gzip` and
`Transfer-Encoding: chunked`, Bun was throwing a `ShortRead` error. This
occurred because the code was checking if `avail_in == 0` (no input
data) and immediately returning an error, without attempting to
decompress what could be a valid empty gzip stream.
## The Fix
Instead of checking `avail_in == 0` before calling `inflate()`, we now:
1. Always call `inflate()` even when `avail_in == 0`
2. Check the return code from `inflate()`
3. If it returns `BufError` with `avail_in == 0`, then we truly need
more data and return `ShortRead`
4. If it returns `StreamEnd`, it was a valid empty gzip stream and we
finish successfully
This approach correctly distinguishes between "no data yet" and "valid
empty gzip stream".
## Why This Works
- A valid empty gzip stream still has headers and trailers (~20 bytes)
- The zlib `inflate()` function can handle empty streams correctly
- `BufError` with `avail_in == 0` specifically means "need more input
data"
## Test Plan
✅ Added regression test in `test/regression/issue/18413.test.ts`
covering:
- Empty chunked gzip response
- Empty non-chunked gzip response
- Empty chunked response without gzip
✅ Verified all existing gzip-related tests still pass
✅ Tested with the original failing case from the issue
🤖 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>
Co-authored-by: Ciro Spaciari <ciro.spaciari@gmail.com>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[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>
## Summary
This PR fixes WebSocket to correctly emit an `error` event before the
`close` event when the handshake fails (e.g., 302 redirects, non-101
status codes, missing headers).
Fixes#14338
## Problem
Previously, when a WebSocket connection failed during handshake (like
receiving a 302 redirect or connecting to a non-WebSocket server), Bun
would only emit a `close` event. This behavior differed from the WHATWG
WebSocket specification and other runtimes (browsers, Node.js with `ws`,
Deno) which emit both `error` and `close` events.
## Solution
Modified `WebSocket::didFailWithErrorCode()` in `WebSocket.cpp` to pass
`isConnectionError = true` for all handshake failure error codes,
ensuring an error event is dispatched before the close event when the
connection is in the CONNECTING state.
## Changes
- Updated error handling in `src/bun.js/bindings/webcore/WebSocket.cpp`
to emit error events for handshake failures
- Added comprehensive test coverage in
`test/regression/issue/14338.test.ts`
## Test Coverage
The test file includes:
1. **Negative test**: 302 redirect response - verifies error event is
emitted
2. **Negative test**: Non-WebSocket HTTP server - verifies error event
is emitted
3. **Positive test**: Successful WebSocket connection - verifies NO
error event is emitted
All tests pass with the fix applied.
🤖 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: Jarred Sumner <jarred@jarredsumner.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
### 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>
## Summary
- Extends the existing string fast path to support simple objects with
primitive values
- Achieves 2-241x performance improvements for postMessage with objects
- Maintains compatibility with existing code while significantly
reducing overhead
## Performance Results
### Bun (this PR)
```
postMessage({ prop: 11 chars string, ...9 more props }) - 648ns (was 1.36µs)
postMessage({ prop: 14 KB string, ...9 more props }) - 719ns (was 2.09µs)
postMessage({ prop: 3 MB string, ...9 more props }) - 1.26µs (was 168µs)
```
### Node.js v24.6.0 (for comparison)
```
postMessage({ prop: 11 chars string, ...9 more props }) - 1.19µs
postMessage({ prop: 14 KB string, ...9 more props }) - 2.69µs
postMessage({ prop: 3 MB string, ...9 more props }) - 304µs
```
## Implementation Details
The fast path activates when:
- Object is a plain object (ObjectType or FinalObjectType)
- Has no indexed properties
- All property values are primitives or strings
- No transfer list is involved
Properties are stored in a `SimpleInMemoryPropertyTableEntry` vector
that holds property names and values directly, avoiding the overhead of
full serialization.
## Test plan
- [x] Added tests for memory usage with simple objects
- [x] Added test for objects exceeding JSFinalObject::maxInlineCapacity
- [x] Created benchmark to verify performance improvements
- [x] Existing structured clone tests continue to pass
🤖 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>
## Summary
Fixes#20596
This PR resolves the "Unable to deserialize data" error when using
`structuredClone()` with nested objects containing `Blob` or `File`
objects, and ensures that `File` objects preserve their `name` property
during structured clone operations.
## Problem
### Issue 1: "Unable to deserialize data" Error
When cloning nested structures containing Blob/File objects,
`structuredClone()` would throw:
```
TypeError: Unable to deserialize data.
```
**Root Cause**: The `StructuredCloneableDeserialize::fromTagDeserialize`
function wasn't advancing the pointer (`m_ptr`) after deserializing
Blob/File objects. This caused subsequent property reads in nested
scenarios to start from the wrong position in the serialized data.
**Affected scenarios**:
- ✅ `structuredClone(blob)` - worked fine (direct cloning)
- ❌ `structuredClone({blob})` - threw error (nested cloning)
- ❌ `structuredClone([blob])` - threw error (array cloning)
- ❌ `structuredClone({data: {files: [file]}})` - threw error (complex
nesting)
### Issue 2: File Name Property Lost
Even when File cloning worked, the `name` property was not preserved:
```javascript
const file = new File(["content"], "test.txt");
const cloned = structuredClone(file);
console.log(cloned.name); // undefined (should be "test.txt")
```
**Root Cause**: The structured clone serialization only handled basic
Blob properties but didn't serialize/deserialize the File-specific
`name` property.
## Solution
### Part 1: Fix Pointer Advancement
**Modified Code Generation** (`src/codegen/generate-classes.ts`):
- Changed `fromTagDeserialize` function signature from `const uint8_t*`
to `const uint8_t*&` (pointer reference)
- Updated implementation to cast pointer correctly: `(uint8_t**)&ptr`
- Fixed both C++ extern declarations and Zig wrapper signatures
**Updated Zig Functions**:
- **Blob.zig**: Modified `onStructuredCloneDeserialize` to take `ptr:
*[*]u8` and advance it by `buffer_stream.pos`
- **BlockList.zig**: Applied same fix for consistency across all
structured clone types
### Part 2: Add File Name Preservation
**Enhanced Serialization Format**:
- Incremented serialization version from 2 to 3 to support File name
serialization
- Added File name serialization using `getNameString()` to handle all
name storage scenarios
- Added proper deserialization with `bun.String.cloneUTF8()` for UTF-8
string creation
- Maintained backwards compatibility with existing serialization
versions
## Testing
Created comprehensive test suite
(`test/js/web/structured-clone-blob-file.test.ts`) with **24 tests**
covering:
### Core Functionality
- Direct Blob/File cloning (6 tests)
- Nested Blob/File in objects and arrays (8 tests)
- Mixed Blob/File scenarios (4 tests)
### Edge Cases
- Blob/File with empty data (6 tests)
- File with empty data and empty name (2 tests)
### Regression Tests
- Original issue 20596 reproduction cases (3 tests)
**Results**: All **24/24 tests pass** (up from 5/18 before the fix)
## Key Changes
1. **src/codegen/generate-classes.ts**:
- Updated `fromTagDeserialize` signature and implementation
- Fixed C++ extern declarations for pointer references
2. **src/bun.js/webcore/Blob.zig**:
- Enhanced pointer advancement in deserialization
- Added File name serialization/deserialization
- Incremented serialization version with backwards compatibility
3. **src/bun.js/node/net/BlockList.zig**:
- Applied consistent pointer advancement fix
4. **test/js/web/structured-clone-blob-file.test.ts**:
- Comprehensive test suite covering all scenarios and edge cases
## Backwards Compatibility
- ✅ Existing structured clone functionality unchanged
- ✅ All other structured clone tests continue to pass (118/118 worker
tests pass)
- ✅ Serialization version 3 supports versions 1-2 with proper fallback
- ✅ No breaking changes to public APIs
## Performance Impact
- ✅ No performance regression in existing functionality
- ✅ Minimal overhead for File name serialization (only when
`is_jsdom_file` is true)
- ✅ Efficient pointer arithmetic for advancement
---
🤖 Generated with [Claude Code](https://claude.ai/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>
