fix: handle requests for double slash in dev

[ascorbic]

Changes

Fixes a bug caused by the fact that new URL("//", "http://localhost") is invalid: it treats the double slash as an empty protocol-relative URL. This caused a 500 error if there was a request for http://localhost//. Now it handles that type of URL correctly, and also redirects to /. This redirect is only implemented for dev, because support for it in platforms is poor, and needs special handling. For that reason we can defer rto the adapters to handle it.

Fixes #12722

Testing

Adds tests

Docs

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Latest commit: ae9f1b9

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[codspeed-hq]

CodSpeed Performance Report

Merging #12733 will not alter performance

_{Comparing double-slash-redirect (ae9f1b9) with main (25c1e59)}

Summary

✅ 6 untouched benchmarks

[ematipico]

I would advise against creating full routes like this because many of those data might not be mandatory, and some of them need to be built using the proper functions. E.g. getPattern or getRouteGenerator.

Plus, we need to take into consideration things like base, trailing slash and more. Follow this pattern:

astro/packages/astro/src/core/routing/manifest/create.ts

Lines 237 to 261 in 901c21f

	components.push(item.file);
	const component = item.file;
	const { trailingSlash } = settings.config;
	const pattern = getPattern(segments, settings.config.base, trailingSlash);
	const generate = getRouteGenerator(segments, trailingSlash);
	const pathname = segments.every((segment) => segment.length === 1 && !segment[0].dynamic)
	? `/${segments.map((segment) => segment[0].content).join('/')}`
	: null;
	const route = joinSegments(segments);
	routes.push({
	route,
	isIndex: item.isIndex,
	type: item.isPage ? 'page' : 'endpoint',
	pattern,
	segments,
	params,
	component,
	generate,
	pathname: pathname || undefined,
	prerender,
	fallbackRoutes: [],
	distURL: [],
	origin: 'project',
	});
	}

It requires more code, but it's more reliable

[ascorbic]

I tried that at first but it didn't seem to be possible for this. Unless I'm missing something, the path isn't one that can be represented with segments. It's for a specific path, regardless of trailing slash or base rules. The pattern needs to match two or more slashes, whether or not trailing slash is enabled, and doesn't apply if base is set. Of the fields I included, it looks like pathname is the only one that's optional.