fs.writeFile writes garbage to file (behavior difference from node)

[tekknolagi]

What version of Bun is running?

1.0.25+a8ff7be64

What platform is your computer?

Linux 5.19.0-38-generic x86_64 x86_64

What steps can reproduce the bug?

https://gist.github.com/tekknolagi/3ba5c6a5bea8e87742642fbb68aba6ef

Run bun run transform.js main.js

What is the expected behavior?

main.js now contains

#!/usr/bin/env node
foo bar
const fs = require('fs');
const path = require('path');
const assert = require('assert');

(note the "foo bar")

What do you see instead?

A bunch of leading 0s:

cedar% xxd main.js 
00000000: 2300 0000 0000 0000 0000 0000 0000 0000  #...............
00000010: 0000 0000 0000 0000 0000 000a 636f 6e73  ............cons
00000020: 7420 6673 203d 2072 6571 7569 7265 2827  t fs = require('
00000030: 6673 2729 3b0a 636f 6e73 7420 7061 7468  fs');.const path
00000040: 203d 2072 6571 7569 7265 2827 7061 7468   = require('path
00000050: 2729 3b0a 636f 6e73 7420 61              ');.const a
cedar%

Additional information

No response

[tekknolagi]

Running bun upgrade gets me to 1.1.3+2615dc742 which still has this issue.

[gvilums]

Simplified repro:

const fs = require('fs/promises');

(async () => {
  const fd = await fs.open("out.txt", "w+");
  await fd.writeFile("x");
  await fd.writeFile("x");
  await fd.close();
})();

node writes xx, bun writes x. This is probably because we're not correctly updating the file offset to write to

[tekknolagi]

Oh wow, that was so fast. Thank you!

…

On Fri, Apr 12, 2024, 16:02 Georgijs ***@***.***> wrote: Closed #10219 <#10219> as completed via #10225 <#10225>. — Reply to this email directly, view it on GitHub <#10219 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AADB6D4CLJUYICSFFKSVDWLY5A4WPAVCNFSM6AAAAABGELMOM6VHI2DSMVQWIX3LMV45UABCJFZXG5LFIV3GK3TUJZXXI2LGNFRWC5DJN5XDWMJSGQ2TGNRWGA3DCMI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[gvilums]

Thanks for reporting the issue!