## Summary
Fixes two critical bugs in Bun Shell:
1. **Memory leaks & incorrect GC reporting**: Shell objects weren't
reporting their memory usage to JavaScriptCore's garbage collector,
causing memory to accumulate unchecked. Also fixes a leak where
`ShellArgs` wasn't being freed in `Interpreter.finalize()`.
2. **Blocking I/O on macOS**: Fixes a bug where writing large amounts of
data (>1MB) to pipes would block the main thread on macOS. The issue:
`sendto()` with `MSG_NOWAIT` flag blocks on macOS despite the flag, so
we now avoid the socket fast path unless the socket is already
non-blocking.
## Changes
- Adds `memoryCost()` and `estimatedSize()` implementations across shell
AST nodes, interpreter, and I/O structures
- Reports estimated memory size to JavaScriptCore GC via
`vm.heap.reportExtraMemoryAllocated()`
- Fixes missing `this.args.deinit()` call in interpreter finalization
- Fixes `BabyList.memoryCost()` to return bytes, not element count
- Conditionally uses socket fast path in IOWriter based on platform and
socket state
## Test plan
- [x] New test: `shell-leak-args.test.ts` - validates memory doesn't
leak during parsing/execution
- [x] New test: `shell-blocking-pipe.test.ts` - validates large pipe
writes don't block the main thread
- [x] Existing shell tests pass
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Claude Bot <claude-bot@bun.sh>
## What does this PR do?
Fixes https://github.com/oven-sh/bun/issues/22650
Fixes https://github.com/oven-sh/bun/issues/22615
Fixes https://github.com/oven-sh/bun/issues/22603
Fixes https://github.com/oven-sh/bun/issues/22602
Fixes a crash that occurred when running shell commands through `bun
run` (package.json scripts) on Windows that use the `&&` operator
followed by an external command.
### The Problem
The minimal reproduction was:
```bash
bun exec 'echo && node --version'
```
This would crash with: `panic(main thread): attempt to use null value`
### Root Causes
Two issues were causing the crash:
1. **Missing top_level_dir**: When `runPackageScriptForeground` creates
a MiniEventLoop for running package scripts, it wasn't setting the
`top_level_dir` field. This caused a null pointer dereference when the
shell tried to access it.
2. **MovableIfWindowsFd handling**: After PR #21800 introduced
`MovableIfWindowsFd` to handle file descriptor ownership on Windows, the
`IOWriter.fd` could be moved to libuv, leaving it null. When the shell
tried to spawn an external command after a `&&` operator, it would crash
trying to access this null fd.
### The Fix
1. Set `mini.top_level_dir = cwd` after initializing the MiniEventLoop
in `run_command.zig`
2. In `IO.zig`, when the fd has been moved to libuv (is null), use
`.inherit` for stdio instead of trying to pass the null fd
### How did you verify your code works?
- Added a regression test that reproduces the issue
- Verified the test fails without the fix and passes with it
- Tested the minimal reproduction command directly
- The fix correctly allows both commands in the `&&` chain to execute
```bash
# Before fix: crashes
> bun exec 'echo test && node --version'
panic(main thread): attempt to use null value
# After fix: works correctly
> bun exec 'echo test && node --version'
test
v22.4.1
```
<sub>
also probably fixes#22615 and fixes#22603 and fixes#22602
</sub>
---------
Co-authored-by: Zack Radisic <zack@theradisic.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>
