### What does this PR do?
Fixes a crash related to the dev server overwriting the uws user context
pointer when setting abort callback.
Adds support for `return new Response(<jsx />, { ... })` and `return
Response.render(...)` and `return Response.redirect(...)`:
- Created a `SSRResponse` class to handle this (see
`JSBakeResponse.{h,cpp}`)
- `SSRResponse` is designed to "fake" being a React component
- This is done in JSBakeResponse::create inside of
src/bun.js/bindings/JSBakeResponse.cpp
- And `src/js/builtins/BakeSSRResponse.ts` defines a `wrapComponent`
function which wraps
the passed in component (when doing `new Response(<jsx />, ...)`). It
does
this to throw an error (in redirect()/render() case) or return the
component.
- Created a `BakeAdditionsToGlobal` struct which contains some
properties
needed for this
- Added some of the properties we need to fake to BunBuiltinNames.h
(e.g.
`$$typeof`), the rationale behind this is that we couldn't use
`structure->addPropertyTransition` because JSBakeResponse is not a final
JSObject.
- When bake and server-side, bundler rewrites `Response ->
Bun.SSRResponse` (see `src/ast/P.zig` and `src/ast/visitExpr.zig`)
- Created a new WebCore body variant (`Render: struct { path: []const u8
}`)
- Created when `return Response.render(...)`
- When handled, it re-invokes dev server to render the new path
Enables server-side sourcemaps for the dev server:
- New source providers for server-side:
(`DevServerSourceProvider.{h,cpp}`)
- IncrementalGraph and SourceMapStore are updated to support this
There are numerous other stuff:
- allow `app` configuration from Bun.serve(...)
- fix errors stopping dev server
- fix use after free related to in
RequestContext.finishRunningErrorHandler
- Request.cookies
- Make `"use client";` components work
- Fix some bugs using `require(...)` in dev server
- Fix catch-all routes not working in the dev server
- Updates `findSourceMappingURL(...)` to use `std.mem.lastIndexOf(...)`
because
the sourcemap that should be used is the last one anyway
---------
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Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Alistair Smith <hi@alistair.sh>
### What does this PR do?
Missing `.t_equals` and `.t_slash` checks. This matches esbuild.
```go
// Returns true if the current less-than token is considered to be an arrow
// function under TypeScript's rules for files containing JSX syntax
func (p *parser) isTSArrowFnJSX() (isTSArrowFn bool) {
oldLexer := p.lexer
p.lexer.Next()
// Look ahead to see if this should be an arrow function instead
if p.lexer.Token == js_lexer.TConst {
p.lexer.Next()
}
if p.lexer.Token == js_lexer.TIdentifier {
p.lexer.Next()
if p.lexer.Token == js_lexer.TComma || p.lexer.Token == js_lexer.TEquals {
isTSArrowFn = true
} else if p.lexer.Token == js_lexer.TExtends {
p.lexer.Next()
isTSArrowFn = p.lexer.Token != js_lexer.TEquals && p.lexer.Token != js_lexer.TGreaterThan && p.lexer.Token != js_lexer.TSlash
}
}
// Restore the lexer
p.lexer = oldLexer
return
}
```
fixes#19697
### How did you verify your code works?
Added some tests.
### What does this PR do?
Fixes code like `[(()=>{})()][''+'c']`.
We were calling `visitExpr` on a node that was already visited. This
code doesn't exist in esbuild, but we should keep it because it's an
optimization.
fixes#18629fixes#15926
### How did you verify your code works?
Manually and added a test.
### What does this PR do?
esbuild returns `left` from the inner loop. This PR matches this
behavior. Before it was breaking out of the inner loop and continuing
through the outer loop, potentially parsing too far.
fixes#22013fixes#22384
### How did you verify your code works?
Added some tests.
---------
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### What does this PR do?
fixes#7157, fixes#14662
migrates pnpm-workspace.yaml data to package.json & converts
pnpm-lock.yml to bun.lock
---
### How did you verify your code works?
manually, tests and real world examples
---------
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Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Dylan Conway <dylan.conway567@gmail.com>
Reduce the size of `bun.webcore.Blob` from 120 bytes to 96. Also make it
ref-counted: in-progress work on improving the bindings generator
depends on this, as it means C++ can pass a pointer to the `Blob` to Zig
without risking it being destroyed if the GC collects the associated
`JSBlob`.
Note that this PR depends on #23013.
(For internal tracking: fixes STAB-1289, STAB-1290)
## Summary
Fixes#22656, #11730, and #7116
Fixes a panic that occurred when macros returned collections containing
three or more arrays or objects.
## Problem
The issue was caused by hash table resizing during recursive processing.
When `this.run()` was called recursively to process nested
arrays/objects, it could add more entries to the `visited` map,
triggering a resize. This would invalidate the `_entry.value_ptr`
pointer obtained from `getOrPut`, leading to memory corruption and
crashes.
## Solution
The fix ensures we handle hash table resizing safely:
1. Use `getOrPut` to reserve an entry and store a placeholder
2. Process all children (which may trigger hash table resizing)
3. Create the final expression with all data
4. Use `put` to update the entry (safe even after resizing)
This approach is applied consistently to both arrays and objects.
## Verification
All three issues have been tested and verified as fixed:
### ✅#22656 - "Panic when returning collections with three or more
arrays or objects"
- **Before**: `panic(main thread): switch on corrupt value`
- **After**: Works correctly
### ✅#11730 - "Constructing deep objects in macros causes segfaults"
- **Before**: `Segmentation fault at address 0x8` with deep nested
structures
- **After**: Handles deep nesting without crashes
### ✅#7116 - "[macro] crash with large complex array"
- **Before**: Crashes with objects containing 50+ properties (hash table
stress)
- **After**: Processes large complex arrays successfully
## Test Plan
Added comprehensive regression tests that cover:
- Collections with 3+ arrays
- Collections with 3+ objects
- Deeply nested structures (5+ levels)
- Objects with many properties (50+) to stress hash table operations
- Mixed collections of arrays and objects
All tests pass with the fix applied.
🤖 Generated with [Claude Code](https://claude.ai/code)
---------
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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?
Fixes accessing the wrong union field.
Resolves BUN-WQF
### How did you verify your code works?
Added a regression test
---------
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## Summary
- Removes unused function and class expression names when
`--minify-syntax` is enabled during bundling
- Adds `--keep-names` flag to preserve original names when minifying
- Matches esbuild's minification behavior
## Problem
When minifying with `--minify-syntax`, Bun was keeping function and
class expression names even when they were never referenced, resulting
in larger bundle sizes compared to esbuild.
**Before:**
```js
export var AB = function A() { };
// Bun output: var AB = function A() {};
// esbuild output: var AB = function() {};
```
## Solution
This PR adds logic to remove unused function and class expression names
during minification, matching esbuild's behavior. Names are only removed
when:
- `--minify-syntax` is enabled
- Bundling is enabled (not transform-only mode)
- The scope doesn't contain direct eval (which could reference the name
dynamically)
- The symbol's usage count is 0
Additionally, a `--keep-names` flag has been added to preserve original
names when desired (useful for debugging or runtime reflection).
## Testing
- Updated existing test in `bundler_minify.test.ts`
- All transpiler tests pass
- Manually verified output matches esbuild for various cases
## Examples
```bash
# Without --keep-names (names removed)
bun build --minify-syntax input.js
# var AB = function() {}
# With --keep-names (names preserved)
bun build --minify-syntax --keep-names input.js
# var AB = function A() {}
```
🤖 Generated with [Claude Code](https://claude.ai/code)
---------
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Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Dylan Conway <dylan.conway567@gmail.com>
## Summary
Implements the `typeof undefined === 'u'` minification optimization from
esbuild in Bun's minifier, and fixes dead code elimination (DCE) for
typeof comparisons with string literals.
### Part 1: Minification Optimization
This optimization transforms:
- `typeof x === "undefined"` → `typeof x > "u"`
- `typeof x !== "undefined"` → `typeof x < "u"`
- `typeof x == "undefined"` → `typeof x > "u"`
- `typeof x != "undefined"` → `typeof x < "u"`
Also handles flipped operands (`"undefined" === typeof x`).
### Part 2: DCE Fix for Typeof Comparisons
Fixed dead code elimination to properly handle typeof comparisons with
strings (e.g., `typeof x <= 'u'`). These patterns can now be correctly
eliminated when they reference unbound identifiers that would throw
ReferenceErrors.
## Before/After
### Minification
Before:
```javascript
console.log(typeof x === "undefined");
```
After:
```javascript
console.log(typeof x > "u");
```
### Dead Code Elimination
Before (incorrectly kept):
```javascript
var REMOVE_1 = typeof x <= 'u' ? x : null;
```
After (correctly eliminated):
```javascript
// removed
```
## Implementation
### Minification
- Added `tryOptimizeTypeofUndefined` function in
`src/ast/visitBinaryExpression.zig`
- Handles all 4 equality operators and both operand orders
- Only optimizes when both sides match the expected pattern (typeof
expression + "undefined" string)
- Replaces "undefined" with "u" and changes operators to `>` (for
equality) or `<` (for inequality)
### DCE Improvements
- Extended `isSideEffectFreeUnboundIdentifierRef` in `src/ast/P.zig` to
handle comparison operators (`<`, `>`, `<=`, `>=`)
- Added comparison operators to `simplifyUnusedExpr` in
`src/ast/SideEffects.zig`
- Now correctly identifies when typeof comparisons guard against
undefined references
## Test Plan
✅ Added comprehensive test in `test/bundler/bundler_minify.test.ts` that
verifies:
- All 8 variations work correctly (4 operators × 2 operand orders)
- Cases that shouldn't be optimized are left unchanged
- Matches esbuild's behavior exactly using inline snapshots
✅ DCE test `dce/DCETypeOfCompareStringGuardCondition` now passes:
- Correctly eliminates dead code with typeof comparison patterns
- Maintains compatibility with esbuild's DCE behavior
🤖 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>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
Co-authored-by: Dylan Conway <dylan.conway567@gmail.com>
## Summary
Implements the `jsxSideEffects` option to control whether JSX elements
are marked as pure for dead code elimination, matching esbuild's
behavior from their TestJSXSideEffects test case.
## Features Added
- **tsconfig.json support**: `{"compilerOptions": {"jsxSideEffects":
true}}`
- **CLI flag support**: `--jsx-side-effects`
- **Dual runtime support**: Works with both classic
(`React.createElement`) and automatic (`jsx`/`jsxs`) JSX runtimes
- **Production/Development modes**: Works in both production and
development environments
- **Backward compatible**: Default value is `false` (maintains existing
behavior)
## Behavior
- **Default (`jsxSideEffects: false`)**: JSX elements marked with `/*
@__PURE__ */` comments (can be eliminated by bundlers)
- **When `jsxSideEffects: true`**: JSX elements NOT marked as pure
(always preserved)
## Example Usage
### tsconfig.json
```json
{
"compilerOptions": {
"jsxSideEffects": true
}
}
```
### CLI
```bash
bun build --jsx-side-effects
```
### Output Comparison
```javascript
// Input: console.log(<div>test</div>);
// Default (jsxSideEffects: false):
console.log(/* @__PURE__ */ React.createElement("div", null, "test"));
// With jsxSideEffects: true:
console.log(React.createElement("div", null, "test"));
```
## Implementation Details
- Added `side_effects: bool = false` field to `JSX.Pragma` struct
- Updated tsconfig.json parser to handle `jsxSideEffects` option
- Added CLI argument parsing for `--jsx-side-effects` flag
- Modified JSX element visiting logic to respect the `side_effects`
setting
- Updated API schema with proper encode/decode support
- Enhanced test framework to support the new JSX option
## Comprehensive Test Coverage (12 Tests)
### Core Functionality (4 tests)
- ✅ Classic JSX runtime with default behavior (includes `/* @__PURE__
*/`)
- ✅ Classic JSX runtime with `side_effects: true` (no `/* @__PURE__ */`)
- ✅ Automatic JSX runtime with default behavior (includes `/* @__PURE__
*/`)
- ✅ Automatic JSX runtime with `side_effects: true` (no `/* @__PURE__
*/`)
### Production Mode (4 tests)
- ✅ Classic JSX runtime in production with default behavior
- ✅ Classic JSX runtime in production with `side_effects: true`
- ✅ Automatic JSX runtime in production with default behavior
- ✅ Automatic JSX runtime in production with `side_effects: true`
### tsconfig.json Integration (4 tests)
- ✅ Default tsconfig.json behavior (automatic runtime, includes `/*
@__PURE__ */`)
- ✅ tsconfig.json with `jsxSideEffects: true` (automatic runtime, no `/*
@__PURE__ */`)
- ✅ tsconfig.json with `jsx: "react"` and `jsxSideEffects: true`
(classic runtime)
- ✅ tsconfig.json with `jsx: "react-jsx"` and `jsxSideEffects: true`
(automatic runtime)
### Snapshot Testing
All tests include inline snapshots demonstrating the exact output
differences, providing clear documentation of the expected behavior.
### Existing Compatibility
- ✅ All existing JSX tests continue to pass
- ✅ Cross-platform Zig compilation succeeds
## Closes
Fixes#22295🤖 Generated with [Claude Code](https://claude.ai/code)
---------
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Co-authored-by: Claude <noreply@anthropic.com>
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Replace `catch bun.outOfMemory()`, which can accidentally catch
non-OOM-related errors, with either `bun.handleOom` or a manual `catch
|err| switch (err)`.
(For internal tracking: fixes STAB-1070)
---------
Co-authored-by: Dylan Conway <dylan.conway567@gmail.com>
For jest compatibility. Fixes#5228
---------
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Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Various types have a `deepClone` method, but there are two different
signatures in use. Some types, like those in the `css` directory, have
an infallible `deepClone` method that cannot return an error. Others,
like those in `ast`, are fallible and can return `error.OutOfMemory`.
Historically, `BabyList.deepClone` has only worked with the fallible
kind of `deepClone`, necessitating the addition of
`BabyList.deepClone2`, which only works with the *in*fallible kind.
This PR:
* Updates `BabyList.deepClone` so that it works with both kinds of
method
* Updates `BabyList.deepClone2` so that it works with both kinds of
method
* Renames `BabyList.deepClone2` to `BabyList.deepCloneInfallible`
* Adds `bun.handleOom(...)`, which is like `... catch bun.outOfMemory()`
but it can't accidentally catch non-OOM-related errors
* Replaces an occurrence of `anyerror` with a more specific error set
(For internal tracking: fixes STAB-969, STAB-970)
---------
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## Summary
- Fix transpiler bug where comma expressions like `(0, obj.method)()`
were incorrectly optimized to `obj.method()`
- This preserved the `this` binding instead of stripping it as per
JavaScript semantics
- Add comprehensive regression test to prevent future issues
## Root Cause
The comma operator optimization in `src/js_parser.zig:7281` was directly
returning the right operand when the left operand had no side effects,
without checking if the expression was being used as a call target.
## Solution
- Added the same `is_call_target` check that other operators (nullish
coalescing, logical OR/AND) use
- When a comma expression is used as a call target AND the right operand
has a value for `this`, preserve the comma expression to strip the
`this` binding
- Follows existing patterns in the codebase for consistent behavior
## Test Plan
- [x] Reproduce the original bug: `(0, obj.method)()` incorrectly
preserved `this`
- [x] Verify fix: comma expressions now correctly strip `this` binding
in function calls
- [x] All existing transpiler tests continue to pass
- [x] Added regression test covering various comma expression scenarios
- [x] Tested edge cases: nested comma expressions, side effects,
different operand types
🤖 Generated with [Claude Code](https://claude.ai/code)
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### What does this PR do?
Reduce stack space usage of parseSuffix
### How did you verify your code works?
---------
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Splits up js_parser.zig into multiple files. Also changes visitExprInOut
to use function calls rather than switch
Not ready:
- [ ] P.zig is ~70,000 tokens, still needs to get smaller
- [x] ~~measure zig build time before & after (is it slower?)~~ no
significant impact
---------
Co-authored-by: pfgithub <6010774+pfgithub@users.noreply.github.com>
### What does this PR do?
Fix: https://github.com/oven-sh/bun/issues/21351
Relevant changes:
Fix advance to properly cleanup success and failed queries that could be
still be in the queue
Always ref before executing
Use stronger atomics for ref/deref and hasPendingActivity
Fallback when thisValue is freed/null/zero and check if vm is being
shutdown
The bug in --hot in `resolveRopeIfNeeded` Issue is not meant to be fixed
in this PR this is a fix for the postgres regression
Added assertions so this bug is easier to catch on CI
### How did you verify your code works?
Test added
---------
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