Add res.redirect response helper

packages/next/next-server/lib/utils.ts

@@ -207,6 +207,7 @@ export type NextApiResponse<T = any> = ServerResponse & {
    */
   json: Send<T>
   status: (statusCode: number) => NextApiResponse<T>
+  redirect: (status: string | number, url: string) => NextApiResponse<T>
 
   /**
    * Set preview data for Next.js' prerender mode

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

@@ -59,6 +59,7 @@ export async function apiResolver(
     apiRes.status = (statusCode) => sendStatusCode(apiRes, statusCode)
     apiRes.send = (data) => sendData(apiReq, apiRes, data)
     apiRes.json = (data) => sendJson(apiRes, data)
+    apiRes.redirect = (status, url) => redirect(apiRes, status, url)
     apiRes.setPreviewData = (data, options = {}) =>
       setPreviewData(apiRes, data, Object.assign({}, apiContext, options))
     apiRes.clearPreviewData = () => clearPreviewData(apiRes)
@@ -209,6 +210,27 @@ export function sendStatusCode(
   return res
 }
 
+/**
+ *
+ * @param res response object
+ * @param [status] `HTTP` status code of redirect
+ * @param url URL of redirect
+ */
+export function redirect(
+  res: NextApiResponse,
+  status: string | number, // If this is a number it's the URL
+  url: string
+): NextApiResponse<any> {
+  if (typeof status === 'string') {
+    url = status
+    status = 302
+  }
+
+  res.writeHead(status, { Location: url })
+  res.end()
+  return res
+}
+
 function sendEtagResponse(
   req: NextApiRequest,
   res: NextApiResponse,