feat(next-auth): awaitable lazy init (#11364)

Author: ThangHuuVu

packages/next-auth/src/index.ts

@@ -72,7 +72,7 @@ import { reqWithEnvURL, setEnvDefaults } from "./lib/env.js"
 import { initAuth } from "./lib/index.js"
 import { signIn, signOut, update } from "./lib/actions.js"
 
-import type { Session } from "@auth/core/types"
+import type { Awaitable, Session } from "@auth/core/types"
 import type { BuiltInProviderType } from "@auth/core/providers"
 import type {
   GetServerSidePropsContext,
@@ -358,7 +358,7 @@ export interface NextAuthResult {
  * import NextAuth from "next-auth"
  * import GitHub from "@auth/core/providers/github"
  *
- * export const { handlers, auth } = NextAuth((req) => {
+ * export const { handlers, auth } = NextAuth(async (req) => {
  *   console.log(req) // do something with the request
  *   return {
  *     providers: [GitHub],
@@ -369,11 +369,11 @@ export interface NextAuthResult {
 export default function NextAuth(
   config:
     | NextAuthConfig
-    | ((request: NextRequest | undefined) => NextAuthConfig)
+    | ((request: NextRequest | undefined) => Awaitable<NextAuthConfig>)
 ): NextAuthResult {
   if (typeof config === "function") {
-    const httpHandler = (req: NextRequest) => {
-      const _config = config(req)
+    const httpHandler = async (req: NextRequest) => {
+      const _config = await config(req)
       setEnvDefaults(_config)
       return Auth(reqWithEnvURL(req), _config)
     }
@@ -383,18 +383,18 @@ export default function NextAuth(
       // @ts-expect-error
       auth: initAuth(config, (c) => setEnvDefaults(c)),
 
-      signIn: (provider, options, authorizationParams) => {
-        const _config = config(undefined)
+      signIn: async (provider, options, authorizationParams) => {
+        const _config = await config(undefined)
         setEnvDefaults(_config)
         return signIn(provider, options, authorizationParams, _config)
       },
-      signOut: (options) => {
-        const _config = config(undefined)
+      signOut: async (options) => {
+        const _config = await config(undefined)
         setEnvDefaults(_config)
         return signOut(options, _config)
       },
-      unstable_update: (data) => {
-        const _config = config(undefined)
+      unstable_update: async (data) => {
+        const _config = await config(undefined)
         setEnvDefaults(_config)
         return update(data, _config)
       },

packages/next-auth/src/lib/index.ts

@@ -121,15 +121,15 @@ function isReqWrapper(arg: any): arg is NextAuthMiddleware | AppRouteHandlerFn {
 export function initAuth(
   config:
     | NextAuthConfig
-    | ((request: NextRequest | undefined) => NextAuthConfig),
+    | ((request: NextRequest | undefined) => Awaitable<NextAuthConfig>),
   onLazyLoad?: (config: NextAuthConfig) => void // To set the default env vars
 ) {
   if (typeof config === "function") {
-    return (...args: WithAuthArgs) => {
+    return async (...args: WithAuthArgs) => {
       if (!args.length) {
         // React Server Components
         const _headers = headers()
-        const _config = config(undefined) // Review: Should we pass headers() here instead?
+        const _config = await config(undefined) // Review: Should we pass headers() here instead?
         onLazyLoad?.(_config)
 
         return getSession(_headers, _config).then((r) => r.json())
@@ -140,7 +140,7 @@ export function initAuth(
         // export { auth as default } from "auth"
         const req = args[0]
         const ev = args[1]
-        const _config = config(req)
+        const _config = await config(req)
         onLazyLoad?.(_config)
 
         // args[0] is supposed to be NextRequest but the instanceof check is failing.
@@ -155,7 +155,7 @@ export function initAuth(
         return async (
           ...args: Parameters<NextAuthMiddleware | AppRouteHandlerFn>
         ) => {
-          const _config = config(args[0])
+          const _config = await config(args[0])
           onLazyLoad?.(_config)
           return handleAuth(args, _config, userMiddlewareOrRoute)
         }
@@ -164,7 +164,7 @@ export function initAuth(
       const request = "req" in args[0] ? args[0].req : args[0]
       const response: any = "res" in args[0] ? args[0].res : args[1]
       // @ts-expect-error -- request is NextRequest
-      const _config = config(request)
+      const _config = await config(request)
       onLazyLoad?.(_config)
 
       // @ts-expect-error -- request is NextRequest