Remix/Single Fetch/Defer To Response

1.0.0Last update Jul 24, 2024

by@jacobparis

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Remix-run/react

Remix / Single Fetch / Defer to response

This codemod removes Remix's defer() helper as it is no longer needed in Single Fetch.

Any headers or status code set via the defer helper are moved to the response argument.

Headers docs

Usage

You can use this codemod with the following command:

codemod remix/single-fetch/defer-to-response

Examples

Input:

export async function loader({}: LoaderFunctionArgs) {
	return defer(
		{
			session: getSession(),
		},
		{
			status: 200,
			headers: {
				'Content-Type': 'application/json',
			},
		},
	)
}

Output:

export async function loader({ response }: LoaderFunctionArgs) {
	response.status = 200
	response.headers.set('Content-Type', 'application/json')
	return {
		session: getSession(),
	}
}

Headers can't be set to a function

If headers are set by a function, we can't automatically map that to the response object.

In this case it'll leave a TODO comment so this can be resolved manually

export async function action({ request }: ActionFunctionArgs) {
	const toastHeaders = createToastHeaders({
		title: 'Deleted',
		description: 'Your connection has been deleted.',
	})
	return defer({ status: 'success' } as const, { headers: toastHeaders })
}

export async function action({ request, response }: ActionFunctionArgs) {
	const toastHeaders = createToastHeaders({
		title: 'Deleted',
		description: 'Your connection has been deleted.',
	})
	// TODO: response.headers = toastHeaders
	return { status: 'success' } as const
}

If response is already in scope

If the function already has a variable named response, such as from another fetch operation, it will conflict with the new response argument.

In this case, it will rename your existing response to response2, which you may want to rename manually to fetchResponse or something more descriptive.

export async function loader({ request }: LoaderFunctionArgs) {
	const response = await fetch(process.env.DATABASE_URL).then(r => r.json())

	return defer(
		{
			session: response.data,
		},
		{
			status: 200,
		},
	)
}

will be transformed to

export async function loader({ request, response }: LoaderFunctionArgs) {
	const response2 = await fetch(process.env.DATABASE_URL).then(r => r.json())
	response.status = 200

	return {
		session: response2.data,
	}
}