fix: use validated args in batch resolver

[Rishab49]

fixes #15112

The PR includes following

• Added a new function run_remote_batch_function which returns validated args along with resolver function, same as run_remote_function but with different return value.
• Updated the logic of batch to use run_remote_batch_function function and use the validated args while calling the resolver function.

---

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[changeset-bot]

🦋 Changeset detected

Latest commit: 2b5a398

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

This PR includes changesets to release 1 package

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@sveltejs/kit	Patch

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[teemingc]

Since this function has the exact same logic as run_remote_function, can we deduplicate this and simply change the returned value of the original function? Refactoring the other usages should be as simple as accessing the resolver property.

[teemingc]

Thanks! The fix is good. Just needs a changeset, a bit of refactoring and a test. The test can be added to packages/kit/test/apps/async/test/test.js and can be similar to the issue reproduction. We'll just need to verify the argument type in the returned function (maybe by sending that data to the page and asserting the correct type value via Playwright?)

[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-kit-15114-svelte.vercel.app/

[Rishab49]

Hi @teemingc,

While writing the test I came across another bug.

Current fix works fine for ssr but when we enable csr then again we get the same unvalidated args to the resolver function.

this is because I have updated the run_remote_function to run_remote_batch_function here

kit/packages/kit/src/runtime/app/server/remote/query.js

Lines 199 to 211 in b5b338c

	const result = await run_remote_batch_function(
	event,
	state,
	false,
	batched.args,
	(array) => Promise.all(array.map(validate)),
	fn
	);
	for (let i = 0; i < batched.resolvers.length; i++) {
	try {
	batched.resolvers[i].resolve(result.resolver(result.validated_args[i], i));
	} catch (error) {

but not here

kit/packages/kit/src/runtime/app/server/remote/query.js

Lines 151 to 163 in 7237e8d

	run: (args) => {
	const { event, state } = get_request_store();
	return run_remote_function(
	event,
	state,
	false,
	args,
	(array) => Promise.all(array.map(validate)),
	fn
	);
	}
	};

and because of this it is using the old returned function without validated args when batch functions are evaluated for csr

kit/packages/kit/src/runtime/server/remote.js

Lines 76 to 82 in 7237e8d

	const args = payloads.map((payload) => parse_remote_arg(payload, transport));
	const get_result = await with_request_store({ event, state }, () => info.run(args));
	const results = await Promise.all(
	args.map(async (arg, i) => {
	try {
	return { type: 'result', data: get_result(arg, i) };
	} catch (error) {

I have made the necessary changes and added test cases as well.

[elliott-with-the-longest-name-on-github]

Looks like there are some linting problems but otherwise this looks pretty good

[elliott-with-the-longest-name-on-github]

I've reworked this a little bit but I'm noticing some weirdness with how we're handling errors, so I'm going to come back to it tomorrow to polish it off. Thank you!

[elliott-with-the-longest-name-on-github]

I'm giving this my stamp of "it's ready" but since I modified it a bunch, I'm going to have @Rich-Harris or @teemingc review before I merge it -- whenever we get their stamp we can merge!

[Rich-Harris]

I think we can simplify it a little #15215

[elliott-with-the-longest-name-on-github]

We went with Rich's solution, but I gave you co-contributor credit on the merge commit. Thank you!