Prerendered root `+server.js` is always saved as `index.html`

[teemingc]

Describe the bug

Line 146 is incorrectly assigning the index.html name to the prerendered +server.js endpoint response because we're on the root path and the statement slices off the / character leaving us with an empty string / falsy value.

kit/packages/kit/src/core/postbuild/prerender.js

Lines 145 to 153 in 4559e66

	function output_filename(path, is_html) {
	const file = path.slice(config.paths.base.length + 1) || 'index.html';
	if (is_html && !file.endsWith('.html')) {
	return file + (file.endsWith('/') ? 'index.html' : '.html');
	}
	return file;
	}

Ideally, it has a .json filename like other prerendered endpoints.

Reproduction

n/a

Logs

No response

System Info

n/a

Severity

serious, but I can work around it

Additional Information

No response

[krish-italiya]

Is the issue still open ?
If yes can I solve it ?

[geodask]

No recent updates here, I’d be glad to take this on. The root path is a bit of a puzzle since /index.html is typically served for /, but with a prerendered +server.js, that default might not suit. What should the root file be named in this case to ensure it’s still accessible when visiting /?

[aewing]

EDIT: What would we expect to happen here? index.[content-type file extension], i.e. index.json?

Static sites wouldn't really know what to do with a non-html static base file, but I guess that's something the user would already have in mind if they needed this functionality.

@eltigerchino

[teemingc]

EDIT: What would we expect to happen here? index.[content-type file extension], i.e. index.json?

Static sites wouldn't really know what to do with a non-html static base file, but I guess that's something the user would already have in mind if they needed this functionality.

@eltigerchino

Yeah, sorry this was a poorly filed issue. It was a while ago but I think this stemmed from someone's reproduction where they had no root page but they had an endpoint in the root instead and the rest of their app in a subroute such as /admin/*. While completely valid, I think it's definitely an edge case since most people wouldn't do this. However, it just doesn't work at the moment due to the issue mentioned earlier.

[aewing]

I implemented a fix in draft right now for this.
The approach I took was to map content-type to extension with a simple heuristic on root-scoped prerender with an endpoint, so for application/json we generate index.json and warn the user about non-standard index files and proper prerender usage.