Ensure path can be specified for clearPreviewData

packages/next/server/api-utils/index.ts

@@ -2,6 +2,7 @@ import type { IncomingMessage } from 'http'
 import type { BaseNextRequest } from '../base-http'
 
 import { NextApiRequest, NextApiResponse } from '../../shared/lib/utils'
+import type { CookieSerializeOptions } from 'next/dist/compiled/cookie'
 
 export type NextApiRequestCookies = Partial<{ [key: string]: string }>
 export type NextApiRequestQuery = Partial<{ [key: string]: string | string[] }>
@@ -98,7 +99,10 @@ export const SYMBOL_PREVIEW_DATA = Symbol(COOKIE_NAME_PRERENDER_DATA)
 export const SYMBOL_CLEARED_COOKIES = Symbol(COOKIE_NAME_PRERENDER_BYPASS)
 
 export function clearPreviewData<T>(
-  res: NextApiResponse<T>
+  res: NextApiResponse<T>,
+  options: {
+    path?: string
+  } = {}
 ): NextApiResponse<T> {
   if (SYMBOL_CLEARED_COOKIES in res) {
     return res
@@ -122,6 +126,9 @@ export function clearPreviewData<T>(
       sameSite: process.env.NODE_ENV !== 'development' ? 'none' : 'lax',
       secure: process.env.NODE_ENV !== 'development',
       path: '/',
+      ...(options.path !== undefined
+        ? ({ path: options.path } as CookieSerializeOptions)
+        : undefined),
     }),
     serialize(COOKIE_NAME_PRERENDER_DATA, '', {
       // To delete a cookie, set `expires` to a date in the past:
@@ -132,6 +139,9 @@ export function clearPreviewData<T>(
       sameSite: process.env.NODE_ENV !== 'development' ? 'none' : 'lax',
       secure: process.env.NODE_ENV !== 'development',
       path: '/',
+      ...(options.path !== undefined
+        ? ({ path: options.path } as CookieSerializeOptions)
+        : undefined),
     }),
   ])
 

packages/next/server/api-utils/node.ts

@@ -494,7 +494,8 @@ export async function apiResolver(
       redirect(apiRes, statusOrUrl, url)
     apiRes.setPreviewData = (data, options = {}) =>
       setPreviewData(apiRes, data, Object.assign({}, apiContext, options))
-    apiRes.clearPreviewData = () => clearPreviewData(apiRes)
+    apiRes.clearPreviewData = (options = {}) =>
+      clearPreviewData(apiRes, options)
     apiRes.revalidate = (
       urlPath: string,
       opts?: {

packages/next/shared/lib/utils.ts

@@ -263,7 +263,11 @@ export type NextApiResponse<T = any> = ServerResponse & {
       path?: string
     }
   ) => NextApiResponse<T>
-  clearPreviewData: () => NextApiResponse<T>
+
+  /**
+   * Clear preview data for Next.js' prerender mode
+   */
+  clearPreviewData: (options?: { path?: string }) => NextApiResponse<T>
 
   /**
    * @deprecated `unstable_revalidate` has been renamed to `revalidate`

test/integration/prerender-preview/pages/api/reset.js

@@ -1,4 +1,10 @@
 export default (req, res) => {
-  res.clearPreviewData()
+  res.clearPreviewData(
+    req.query.cookiePath
+      ? {
+          path: req.query.cookiePath,
+        }
+      : undefined
+  )
   res.status(200).end()
 }

test/integration/prerender-preview/test/index.test.js

@@ -211,6 +211,38 @@ function runTests(startServer = nextStart) {
     expect(cookies[1]).not.toHaveProperty('Max-Age')
   })
 
+  it('should return cookies to be expired on reset request with path specified', async () => {
+    const res = await fetchViaHTTP(
+      appPort,
+      '/api/reset',
+      { cookiePath: '/blog' },
+      { headers: { Cookie: previewCookieString } }
+    )
+    expect(res.status).toBe(200)
+
+    const cookies = res.headers
+      .get('set-cookie')
+      .replace(/(=(?!Lax)\w{3}),/g, '$1')
+      .split(',')
+      .map(cookie.parse)
+
+    expect(cookies.length).toBe(2)
+    expect(cookies[0]).toMatchObject({
+      Path: '/blog',
+      SameSite: 'None',
+      Expires: 'Thu 01 Jan 1970 00:00:00 GMT',
+    })
+    expect(cookies[0]).toHaveProperty('__prerender_bypass')
+    expect(cookies[0]).not.toHaveProperty('Max-Age')
+    expect(cookies[1]).toMatchObject({
+      Path: '/blog',
+      SameSite: 'None',
+      Expires: 'Thu 01 Jan 1970 00:00:00 GMT',
+    })
+    expect(cookies[1]).toHaveProperty('__next_preview_data')
+    expect(cookies[1]).not.toHaveProperty('Max-Age')
+  })
+
   it('should pass undefined to API routes when not in preview', async () => {
     const res = await fetchViaHTTP(appPort, `/api/read`)
     const json = await res.json()