^3.1.1 missing finished, pipeline when READABLE_STREAM env var is 'disable'

[trxcllnt]

@mcollina We're running into the same issue as fastify/fastify#1413 after updating to fastify rc.6. Looking closer, it seems the main readable-stream ^3.x export is missing the new finished and pipeline methods when running with READABLE_STREAM=disable:

readable-stream/readable.js

Lines 2 to 11 in 1df8b0c

	if (process.env.READABLE_STREAM === 'disable' && Stream) {
	module.exports = Stream;
	exports = module.exports = Stream.Readable;
	exports.Readable = Stream.Readable;
	exports.Writable = Stream.Writable;
	exports.Duplex = Stream.Duplex;
	exports.Transform = Stream.Transform;
	exports.PassThrough = Stream.PassThrough;
	exports.Stream = Stream;
	} else {

Unsetting READABLE_STREAM isn't an option since many dependencies are stuck on readable-stream <= 3.x, and we need the consistency of using node-core streams across the board. I'm able to fix this (for now) by doing an Object.assign(require('readable-stream'), require('stream')) before requiring fastify, but this may not be a stable solution as more libraries update to readable-stream 3.x.

[mcollina]

I would not recommend running with READABLE_STREAM=disable in production, but you are right, this is a bug. Would you like to send a PR?

[trxcllnt]

I'd be happy to, is the Object.assign() approach ok with you?

I would not recommend running with READABLE_STREAM=disable in production

I understand the risk of readable-stream shipping features (and other libs relying on those features) before they land in node core, but that's an acceptable risk considering the alternative is a maelstrom of incompatible readable-stream versions (e.g. flowing/non-flowing, no Symbol.asyncIterator etc.).

I'm curious, do you have other reasons to not recommend node's built-in streams in production?

[qm3ster]

I too, remain curious!