Use readable byte stream for Blob.stream() and Response.body

[saschanaz]

Corresponds to whatwg/fetch#1593 and w3c/FileAPI#188.

[crowlKats]

We actually already use readable byte streams for both of these APIs which seem to align with behaviour in the spec PRs, so will close this

[saschanaz]

Oh, interesting! In that case are you interested to how to spec the behavior? whatwg/fetch#1593 (comment)

[saschanaz]

BTW, new Blob([]).stream().getReader({ mode: 'byob' }) succeeds but new Response(new Uint8Array([1,2])).body.getReader({mode: 'byob'}) still fails on Deno 1.29.2. I guess the Fetch change didn't land to the stable version yet?

[saschanaz]

(await fetch('https://example.com')).body.getReader({mode: 'byob'}) does succeed, so I guess the only remaining item is to extract byte stream from BodyInit.

[crowlKats]

actually, apparently i missed the fact that there was a recent-ish change #16038 that might have changed our behaviour.

[crowlKats]

BTW, new Blob([]).stream().getReader({ mode: 'byob' }) succeeds but new Response(new Uint8Array([1,2])).body.getReader({mode: 'byob'}) still fails on Deno 1.29.2. I guess the Fetch change didn't land to the stable version yet?

seems like Response constructor with either string or typedarray has a different path, and is creating the stream differently:

deno/ext/fetch/22_body.js

Lines 95 to 100 in 10e4b2e

	this.streamOrStatic = new ReadableStream({
	start(controller) {
	controller.enqueue(chunkToU8(body));
	controller.close();
	},
	});

looks like a trivial change

[crowlKats]

Oh, interesting! In that case are you interested to how to spec the behavior? whatwg/fetch#1593 (comment)

cc @lucacasonato

[jimmywarting]

• (await fetch('https://example.com')).body.getReader({mode: 'byob'}) works
• new Response('foo').body.getReader({mode: 'byob'}) dose not...