FileSink.write incoherencies

[oguimbal]

What version of Bun is running?

1.1.17+bb66bba1b

What platform is your computer?

Darwin 23.1.0 arm64 arm

What steps can reproduce the bug?

Run the below code, which is supposed to stream data through cat.

const p = Bun.spawn(['cat'], {
    stdin: 'pipe',
    stdout: 'pipe',
})

const r = p.stdout.getReader()
while (true) {
    const buf = new Uint8Array(1_000_000);
    const writeResult = p.stdin.write(buf);
    const written = await writeResult;
    console.log('writen', writeResult, ' => ', written);

    let i = 0;
    while (true) {
        const { value } = await r.read();
        i += value?.length ?? 0;
        if (i >= written) {
            break;
        }
    }
}

What is the expected behavior?

1. I'd not expect FileSink.write to randomly return a promise

2. I'd definitely not expect FileSink.write to return a number greater than the size of the buffer I passed to it

What do you see instead?

Additional information

No response