`handleMissingId` should treat `#top` as a valid ID

[josh-collinsworth]

Describe the bug

The ID #top is a perfectly valid href attribute, which can be used to scroll a user to the top of an HTML document. Per the HTML spec:

If decodedFragment is an ASCII case-insensitive match for the string top, then return the top of the document.

This is also confirmed by MDN.

However, at build time, an anchor tag with href="#top" will throw an error:

Error: The following pages contain links to /foo/bar#top, but no element with id="top" exists on /foo/bar - see the `handleMissingId` option in https://kit.svelte.dev/docs/configuration#prerender for more info:

This shouldn't be the case, as #top is, again, a valid HTML href value.

Further, users shouldn't be forced to adjust their compiler options simply to be able to use something that's in the spec.

Reproduction

Run a static build on a SvelteKit site with a <a href="#top">Top</a> link present

Logs

9:24:57 AM: Failed during stage 'building site': Build script returned non-zero exit code: 2 (https://ntl.fyi/exit-code-2)
9:24:57 AM: file:///opt/build/repo/node_modules/@sveltejs/kit/src/core/postbuild/prerender.js:53
9:24:57 AM: 					throw new Error(format(details));
9:24:57 AM: 					      ^
9:24:57 AM: Error: The following pages contain links to /blog/antiquated-react#top, but no element with id="top" exists on /blog/antiquated-react - see the `handleMissingId` option in https://kit.svelte.dev/docs/configuration#prerender for more info:
9:24:57 AM:   - /blog/antiquated-react
9:24:57 AM:     at file:///opt/build/repo/node_modules/@sveltejs/kit/src/core/postbuild/prerender.js:53:12
9:24:57 AM:     at prerender (file:///opt/build/repo/node_modules/@sveltejs/kit/src/core/postbuild/prerender.js:398:4)
9:24:57 AM:     at async process.<anonymous> (file:///opt/build/repo/node_modules/@sveltejs/kit/src/utils/fork.js:25:17)
9:24:57 AM: Node.js v19.3.0
9:24:57 AM: [vite-plugin-sveltekit-compile] Failed with code 1
9:24:57 AM: error during build:
9:24:57 AM: Error: Failed with code 1
9:24:57 AM:     at ChildProcess.<anonymous> (file:///opt/build/repo/node_modules/@sveltejs/kit/src/utils/fork.js:68:13)
9:24:57 AM:     at ChildProcess.emit (node:events:513:28)
9:24:57 AM:     at ChildProcess._handle.onexit (node:internal/child_process:293:12)
9:24:57 AM: ​
9:24:57 AM: "build.command" failed                                        
9:24:57 AM: ────────────────────────────────────────────────────────────────

System Info

System:
    OS: macOS 14.5
    CPU: (12) arm64 Apple M2 Pro
    Memory: 158.53 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 19.3.0 - ~/.nvm/versions/node/v19.3.0/bin/node
    Yarn: 1.22.19 - ~/.nvm/versions/node/v19.3.0/bin/yarn
    npm: 9.2.0 - ~/.nvm/versions/node/v19.3.0/bin/npm
  Browsers:
    Chrome: 126.0.6478.61
    Edge: 126.0.2592.61
    Safari: 17.5

Severity

annoyance

Additional Information

No response