[feat] customizable output file names for prerendering

[dishuostec]

Before submitting the PR, please make sure you do the following

• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
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• Ideally, include a test that fails without this PR but passes with it.

Tests

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Ref #1443

This PR provide an optional callback to custom entry names for adapter-static.

Example:

• blog/hello-world.html.svelte => blog/hello-world.html
• about.svelte => about.html

// svelte.config.js
import adapter from '@sveltejs/adapter-static';
import { format, parse } from 'path';

/** @type {import('@sveltejs/kit').Config} */
const config = {
	kit: {
		adapter: adapter({
			fallback: '200.html',
			outputFileName: ({ path, is_html }) => {
				if (!is_html) return path;

				let { root, dir, name, ext } = parse(path);

				if (!ext) ext = '.html';

				return format({ root, dir, name, ext });
			}
		}),
		target: '#svelte'
	}
};

export default config;

[changeset-bot]

🦋 Changeset detected

Latest commit: 90c596d

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

This PR includes changesets to release 2 packages

Name	Type
@sveltejs/kit	Patch
@sveltejs/adapter-static	Patch

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[benmccann]

can we test this feature using an existing test project? we try to minimize the number of test projects we create in order to avoid time starting / stopping the server, etc.

[dishuostec]

I have no idea how to test in one project using two different adapter options. The structure of build dir is totally different with or without this option. May be we can use subdir to split different strategies?

routes
├── default
│   ├── index.svelte
│   └── sub
│       └── page.svelte
└── strip-index
    ├── index.svelte
    └── sub
        └── page.svelte

outputFileName: ({ path, is_html }) => {
	if (!is_html) return path;

	if (path.startsWith('/strip-index/')) {
		// return custom name
	}

	// return default name
}

[dishuostec]

According to the coding style guidelines, renamed API option name and use deconstruction of object as argument.
Added changeset.

[benmccann]

Rather than include the code here, I would describe it textually like:

By default, prerendered html pages are output as index.html files in the directory matching the URL path.

And then maybe show an example of doing something else with it

[dishuostec]

What about this one:

---

outputFileName

A optional function that is called per entry to return the destination to write to.

By default, prerendered html pages are output as index.html files in the directory matching the URL path.

URL	output file
/	/index.html
/foo	/foo/index.html
/bar.html	/bar.html/index.html
/foo/bar	/foo/bar/index.html

For example, you may prefer /foo.html to /foo/index.html:

import { format, parse } from 'path';

outputFileName: ({ path, is_html }) => {
	if (!is_html) return path;

	let { root, dir, name, ext } = parse(path);

	if (!ext) ext = '.html';

	return format({ root, dir, name, ext });
}

[benmccann]

It looks like pnpm lint is failing. Please run pnpm format to fix it

[benmccann]

I'd expect a new option to go with the pre-rendering options. There's nothing specific about adapter-static to it

https://kit.svelte.dev/docs#configuration-prerender

[benmccann]

Thank you for this PR. I discussed it with the rest of the maintainers at today's maintainer's meeting and the thought was that we should just add a boolean to add the .html extension. Folks thought the need for the option was fairly specific and that adding a function was too broad of a solution and would be harder to use for the more narrow need that has been expressed

I really appreciate all the work that you've done on this. I'm going to go ahead and close it though given the feedback from the maintainers group. I'd be happy to consider a PR for the boolean option though