import { stringifyCookie } from '../../web/spec-extension/cookies' import type { I18NConfig } from '../../config-shared' import { NextURL } from '../next-url' import { toNodeOutgoingHttpHeaders, validateURL } from '../utils' import { ReflectAdapter } from './adapters/reflect' import { ResponseCookies } from './cookies' const INTERNALS = Symbol('internal response') const REDIRECTS = new Set([301, 302, 303, 307, 308]) function handleMiddlewareField( init: MiddlewareResponseInit | undefined, headers: Headers ) { if (init?.request?.headers) { if (!(init.request.headers instanceof Headers)) { throw new Error('request.headers must be an instance of Headers') } const keys = [] for (const [key, value] of init.request.headers) { headers.set('x-middleware-request-' + key, value) keys.push(key) } headers.set('x-middleware-override-headers', keys.join(',')) } } /** * This class extends the [Web `Response` API](https://developer.mozilla.org/docs/Web/API/Response) with additional convenience methods. * * Read more: [Next.js Docs: `NextResponse`](https://nextjs.org/docs/app/api-reference/functions/next-response) */ export class NextResponse extends Response { [INTERNALS]: { cookies: ResponseCookies url?: NextURL body?: Body } constructor(body?: BodyInit | null, init: ResponseInit = {}) { super(body, init) const headers = this.headers const cookies = new ResponseCookies(headers) const cookiesProxy = new Proxy(cookies, { get(target, prop, receiver) { switch (prop) { case 'delete': case 'set': { return (...args: [string, string]) => { const result = Reflect.apply(target[prop], target, args) const newHeaders = new Headers(headers) if (result instanceof ResponseCookies) { headers.set( 'x-middleware-set-cookie', result .getAll() .map((cookie) => stringifyCookie(cookie)) .join(',') ) } handleMiddlewareField(init, newHeaders) return result } } default: return ReflectAdapter.get(target, prop, receiver) } }, }) this[INTERNALS] = { cookies: cookiesProxy, url: init.url ? new NextURL(init.url, { headers: toNodeOutgoingHttpHeaders(headers), nextConfig: init.nextConfig, }) : undefined, } } [Symbol.for('edge-runtime.inspect.custom')]() { return { cookies: this.cookies, url: this.url, // rest of props come from Response body: this.body, bodyUsed: this.bodyUsed, headers: Object.fromEntries(this.headers), ok: this.ok, redirected: this.redirected, status: this.status, statusText: this.statusText, type: this.type, } } public get cookies() { return this[INTERNALS].cookies } static json( body: JsonBody, init?: ResponseInit ): NextResponse { const response: Response = Response.json(body, init) return new NextResponse(response.body, response) } static redirect(url: string | NextURL | URL, init?: number | ResponseInit) { const status = typeof init === 'number' ? init : init?.status ?? 307 if (!REDIRECTS.has(status)) { throw new RangeError( 'Failed to execute "redirect" on "response": Invalid status code' ) } const initObj = typeof init === 'object' ? init : {} const headers = new Headers(initObj?.headers) headers.set('Location', validateURL(url)) return new NextResponse(null, { ...initObj, headers, status, }) } static rewrite( destination: string | NextURL | URL, init?: MiddlewareResponseInit ) { const headers = new Headers(init?.headers) headers.set('x-middleware-rewrite', validateURL(destination)) handleMiddlewareField(init, headers) return new NextResponse(null, { ...init, headers }) } static next(init?: MiddlewareResponseInit) { const headers = new Headers(init?.headers) headers.set('x-middleware-next', '1') handleMiddlewareField(init, headers) return new NextResponse(null, { ...init, headers }) } } interface ResponseInit extends globalThis.ResponseInit { nextConfig?: { basePath?: string i18n?: I18NConfig trailingSlash?: boolean } url?: string } interface ModifiedRequest { /** * If this is set, the request headers will be overridden with this value. */ headers?: Headers } interface MiddlewareResponseInit extends globalThis.ResponseInit { /** * These fields will override the request from clients. */ request?: ModifiedRequest }