Buffer.writeUInt64BE should return offset plus bytes written #17694

What version of Bun is running?

1.2.3+8c4d3ff80

What platform is your computer?

Linux 6.13.3-arch1-1 x86_64 unknown

What steps can reproduce the bug?

const buf = Buffer.alloc(8)
buf.writeBigUInt64BE(7n) // returns 0

writeBigUInt64BE seems to return the offset without the number of bytes written. This diverges from nodejs.

What is the expected behavior?

https://nodejs.org/api/buffer.html#bufwritebiguint64bevalue-offset

buf.writeBigUInt64BE(value[, offset])

• value Number to be written to buf.
• offset Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8. Default: 0.
• Returns: offset plus the number of bytes written.

Writes value to buf at the specified offset as big-endian.

This method should return the offset (default=0) + 8 since it always writes 8 bytes.

What do you see instead?

No response

Additional information

I suspect other buffer write methods may have the same problem (with zero evidence).