[Javascript] tableToIPC has off-by-one errors in the generated IPC byte length

[aarashy]

Describe the bug, including details regarding any error messages, version, and platform.

Hello, I filed an issue with arrow-rs because panics were being triggered in their IPC byte parsing functions.
apache/arrow-rs#3215 (comment)

The input IPC bytes were the result of tableToIPC. According to the info I've gathered in my other issue, it seems like tableToIPC is not correctly padding and instead incorrectly truncating bits in cases where the length of a record batch is not divisible by 8.

For example, the Null Bit Buffer encodes whether each row is null or not using 1 bit. My record batch has length 518, which is not divisible by 8 (64.75). Some parsing/validation inside arrow-rs is therefore expecting the null bit buffer to be 65 bytes long, but it's only 64 bytes long.

Component(s)

Format, Integration, JavaScript

[aarashy]

@trxcllnt - Hello! You seem to be the biggest contributor to this file https://github.com/apache/arrow/blob/5611f2bd0d6136b005d137a84b50709fc5c813bb/js/src/ipc/writer.ts

I wonder if you have any insight on what might have been happening here.

[trxcllnt]

@aarashy thanks for the report, I'll take a look and try to repro.