feat: allow adapters to override getRequest and setResponse

.changeset/rare-schools-itch.md

@@ -0,0 +1,6 @@
+---
+"@sveltejs/kit": minor
+---
+
+feat: allow adapters to override getRequest and setResponse
+

documentation/docs/25-build-and-deploy/99-writing-adapters.md

@@ -13,6 +13,8 @@ type AdapterSpecificOptions = any;
 
 // @filename: index.js
 // ---cut---
+import { getRequest, setResponse } from '@sveltejs/kit/node';
+
 /** @param {AdapterSpecificOptions} options */
 export default function (options) {
 	/** @type {import('@sveltejs/kit').Adapter} */
@@ -40,6 +42,15 @@ export default function (options) {
 				// Return `false if it can't, or throw a descriptive error.
 			}
 		},
+		getRequest(options) {
+			const request = getRequest(options);
+			// modify the Request object here if needed
+			return request;
+		},
+		setResponse(res, response) {
+			// handle WebSockets here, for example
+			setResponse(res, response);
+		},
 		vite: {
 			plugins: {
 				// add plugins here to integrate with Vite
@@ -53,7 +64,7 @@ export default function (options) {
 }
 ```
 
-Of these, `name` and `adapt` are required. `emulate`, `vite`, and `supports` are optional.
+Of these, `name` and `adapt` are required. `emulate`, `vite`, `getRequest`, `setResponse`, and `supports` are optional.
 
 Within the `adapt` method, there are a number of things that an adapter should do:
 

packages/kit/src/exports/public.d.ts

@@ -23,6 +23,7 @@ import { SvelteConfig } from '@sveltejs/vite-plugin-svelte';
 import { Plugin } from 'vite';
 import { RouteId as AppRouteId, LayoutParams as AppLayoutParams } from '$app/types';
 import { ParamMatcher } from '@sveltejs/kit/params';
+import { getRequest, setResponse } from '@sveltejs/kit/node';
 
 export { PrerenderOption } from '../types/private.js';
 
@@ -58,6 +59,18 @@ export interface Adapter {
 		 */
 		instrumentation?: () => boolean;
 	};
+	/**
+	 * This function overrides the default behavior to convert an `http.IncomingMessage` to a `Request` object.
+	 * To call the original setRequest function, import it from `@sveltejs/kit/node`.
+	 * @since 3.0.0
+	 */
+	getRequest?: typeof getRequest;
+	/**
+	 * This function overrides the default behavior to write a `Response` object to an `http.ServerResponse`.
+	 * To call the original setResponse function, import it from `@sveltejs/kit/node`.
+	 * @since 3.0.0
+	 */
+	setResponse?: typeof setResponse;
 	/**
 	 * Creates an `Emulator`, which allows the adapter to influence the environment
 	 * during dev, build and prerendering.

packages/kit/src/exports/vite/dev/index.js

@@ -594,7 +594,7 @@ export async function dev(
 					read: (file) => createReadableStream(from_fs(file))
 				});
 
-				const request = getRequest({
+				const request = (svelte_config.kit.adapter?.getRequest ?? getRequest)({
 					base,
 					request: req
 				});
@@ -646,11 +646,11 @@ export async function dev(
 					// @ts-expect-error
 					serve_static_middleware.handle(req, res, () => {
 						log_response(rendered.status, request);
-						setResponse(res, rendered);
+						(svelte_config.kit.adapter?.setResponse ?? setResponse)(res, rendered);
 					});
 				} else {
 					log_response(rendered.status, request);
-					setResponse(res, rendered);
+					(svelte_config.kit.adapter?.setResponse ?? setResponse)(res, rendered);
 				}
 			} catch (e) {
 				const error = coalesce_to_error(e);

packages/kit/src/exports/vite/preview/index.js

@@ -204,12 +204,12 @@ export async function preview(vite, vite_config, svelte_config) {
 		vite.middlewares.use(async (req, res) => {
 			const host = req.headers[':authority'] || req.headers.host;
 
-			const request = getRequest({
+			const request = (svelte_config.kit.adapter?.getRequest ?? getRequest)({
 				base: `${protocol}://${host}`,
 				request: req
 			});
 
-			setResponse(
+			(svelte_config.kit.adapter?.setResponse ?? setResponse)(
 				res,
 				await server.respond(request, {
 					getClientAddress: () => {

packages/kit/types/index.d.ts

@@ -5,6 +5,7 @@ declare module '@sveltejs/kit' {
 	import type { SvelteConfig } from '@sveltejs/vite-plugin-svelte';
 	import type { Plugin } from 'vite';
 	import type { RouteId as AppRouteId, LayoutParams as AppLayoutParams } from '$app/types';
+	import type { getRequest, setResponse } from '@sveltejs/kit/node';
 	import type { StandardSchemaV1 } from '@standard-schema/spec';
 	// @ts-ignore this is an optional peer dependency so could be missing. Written like this so dts-buddy preserves the ts-ignore
 	type Span = import('@opentelemetry/api').Span;
@@ -38,6 +39,18 @@ declare module '@sveltejs/kit' {
 			 */
 			instrumentation?: () => boolean;
 		};
+		/**
+		 * This function overrides the default behavior to convert an `http.IncomingMessage` to a `Request` object.
+		 * To call the original setRequest function, import it from `@sveltejs/kit/node`.
+		 * @since 3.0.0
+		 */
+		getRequest?: typeof getRequest;
+		/**
+		 * This function overrides the default behavior to write a `Response` object to an `http.ServerResponse`.
+		 * To call the original setResponse function, import it from `@sveltejs/kit/node`.
+		 * @since 3.0.0
+		 */
+		setResponse?: typeof setResponse;
 		/**
 		 * Creates an `Emulator`, which allows the adapter to influence the environment
 		 * during dev, build and prerendering.