is-deflate

snippet::is-deflate-buffer

Simple or drop-in replacement

This package is no longer necessary. You can check the first two bytes of a buffer to detect if it's compressed using deflate.

// example

function isDeflate(buf) {
	if (buf.length < 2 || buf[0] !== 0x78)
		return false;
	const b = buf[1];
	return b === 1 || b === 0x9c || b === 0xda;
}