Undici

[Rich-Harris]

#5113. This replaces node-fetch with undici, which is more standards-compliant and is built in to Node 18. This will unlock using web streams for request and response bodies, on platforms that support them.

TODO:

• get remaining tests passing
• replace git dependency with undici@latest when feat: remove headers filtering nodejs/undici#1469 is released
• only apply polyfills where necessary
• document addition of web streams in https://kit.svelte.dev/docs/web-standards

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🦋 Changeset detected

Latest commit: 1ef7340

The changes in this PR will be included in the next version bump.

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[Rich-Harris]

The handles large responses test is failing for reasons I have been unable to figure out

kit/packages/kit/test/apps/basics/test/test.js

Lines 1351 to 1385 in e38637d

	test('handles large responses', async ({ page }) => {
	await page.goto('/load');
	const chunk_size = 50000;
	const chunk_count = 100;
	const total_size = chunk_size * chunk_count;
	let chunk = '';
	for (let i = 0; i < chunk_size; i += 1) {
	chunk += String(i % 10);
	}
	let times_responded = 0;
	const { port, server } = await start_server(async (req, res) => {
	if (req.url === '/large-response.json') {
	times_responded += 1;
	res.writeHead(200, {
	'Access-Control-Allow-Origin': '*'
	});
	for (let i = 0; i < chunk_count; i += 1) {
	if (!res.write(chunk)) {
	await new Promise((fulfil) => {
	res.once('drain', () => {
	fulfil(undefined);
	});
	});
	}
	}
	res.end();
	}
	});

[Rich-Harris]

oh and a bunch of packaging tests have started failing for absolutely no good reason whatsoever. jfc software is awful

[Rich-Harris]

ok i think the unrelated packaging tests are failing because this PR installs undici from git, which means it's pulling in dev dependencies that mess up some stuff. programming is super fun

[pixelmund]

Seems like undici had a new release, so we can remove the git dependency now.

[Rich-Harris]

I don't really understand why handles large responses is starting a second server

Because before undici it wasn't possible to generate a chunked response from a SvelteKit app. That's no longer the case, so I've updated the test — instead of generating the response in a second server, it does it in an endpoint