The slicing method in the buffer.Blob is wrong according to the spec

[jimmywarting]

• Version: v15.8.0
• Platform: Darwin Kernel Version 20.1.0: Sat Oct 31 00:07:11 PDT 2020; root:xnu-7195.50.7~2/RELEASE_X86_64 x86_64
• Subsystem:

Thought I would try it out and help you find some quirks before making it stable. The slicing method is wrong

What steps will reproduce the bug?

import { Blob } from 'buffer'

new Blob().slice(0, 500)
new Blob(['abc']).slice(-1).text()        // c
new Blob(['abc']).slice(0, -1).text()     // ab
new Blob(['abcdef']).slice(-3, -1).text() // de

How often does it reproduce?

Happens everytime

What is the expected behavior?

...to get a new Blob slice without throwing any error.
the slicing method should behave similar like you slice a String or a ArrayBuffer

But internally it can be more complicated then that if it should operate on multiple blob parts that are async (see #37338)

What do you see instead?

Uncaught:
RangeError [ERR_OUT_OF_RANGE]: The value of "end" is out of range.
It must be less than or equal to length. Received 500

This should not happen.