fix: allow routes to contain [ and ] via the [x+5b] and [x+5d] escapes

[Nic-Polumeyv]

The [ and ] escapes prescribed in documentation/docs/30-advanced/10-advanced-routing.md have never worked: a route directory named [x+5b] fails the build with Invalid regular expression: /^/\\[/?$/: Unterminated character class, and [x+5d] compiles to a pattern that cannot match /]. Introduced with the escape syntax itself in #7644.

escape() escapes [ and ] first to protect the %2[Ff] and %3[Ff] classes the URL substitutions emit, then its final pass re-escapes those backslashes because \\ is in its character class. Regex escaping now runs before the substitutions rather than around them.

parse_route_id output is byte-identical to version-3 for every printable ASCII character and 23 mixed route ids; only [x+5b] and [x+5d] change.

[pkg-svelte-dev]

Install the latest version of @sveltejs/kit from 6031e0c:

pnpm add https://pkg.svelte.dev/@sveltejs/kit/c/6031e0c2ab590c8329bbf056f4d2f0382613bc00

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/kit/pr/16569

Note

This PR is from a fork. A maintainer must approve approve each commit before it can be built and installed.

[changeset-bot]

🦋 Changeset detected

Latest commit: 6031e0c

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

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@sveltejs/kit	Patch

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[Nic-Polumeyv]

#16570 fixes the other half of this: resolve() returns escape sequences verbatim, so a pathname built from an escaped route id doesn't match the route. Independent changes, but with both, all 94 printable ASCII escape sequences resolve to a pathname their own pattern matches.