fix: truly replace .flat() to support Node <11 again (#1691)

* Fix validation of provider existence before looking for protection property

* Use optional chaining

.github/labeler.yml

@@ -1,5 +1,6 @@
 test:
   - test/**/*
+  - types/tests/**/*
 
 documentation:
   - www/**/*
@@ -32,4 +33,7 @@ client:
 
 pages:
   - src/server/pages/**/*
-  - www/docs/configuration/pages.md
+  - www/docs/configuration/pages.md
+
+TypeScript:
+  - types/**/*

package-lock.json

@@ -4450,6 +4450,12 @@
             "yallist": "^3.0.2"
           }
         },
+        "y18n": {
+          "version": "4.0.1",
+          "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.1.tgz",
+          "integrity": "sha512-wNcy4NvjMYL8gogWWYAO7ZFWFfHcbdbE57tZO8e4cbpj8tfUcwrwqSl3ad8HxpYWCdXcJUCeKKZS62Av1affwQ==",
+          "dev": true
+        },
         "yallist": {
           "version": "3.1.1",
           "resolved": "https://registry.npmjs.org/yallist/-/yallist-3.1.1.tgz",
@@ -4801,11 +4807,6 @@
             "strip-ansi": "^6.0.0"
           }
         },
-        "y18n": {
-          "version": "5.0.5",
-          "resolved": "https://registry.npmjs.org/y18n/-/y18n-5.0.5.tgz",
-          "integrity": "sha512-hsRUr4FFrvhhRH12wOdfs38Gy7k2FFzB9qgN9v3aLykRq0dRcdcpz5C9FxdS2NuhOrI/628b/KSTJ3rwHysYSg=="
-        },
         "yargs": {
           "version": "16.2.0",
           "resolved": "https://registry.npmjs.org/yargs/-/yargs-16.2.0.tgz",
@@ -13875,8 +13876,9 @@
           "dev": true
         },
         "y18n": {
-          "version": "4.0.0",
-          "bundled": true,
+          "version": "4.0.1",
+          "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.1.tgz",
+          "integrity": "sha512-wNcy4NvjMYL8gogWWYAO7ZFWFfHcbdbE57tZO8e4cbpj8tfUcwrwqSl3ad8HxpYWCdXcJUCeKKZS62Av1affwQ==",
           "dev": true
         },
         "yallist": {
@@ -15042,6 +15044,12 @@
             "is-number": "^7.0.0"
           }
         },
+        "y18n": {
+          "version": "4.0.1",
+          "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.1.tgz",
+          "integrity": "sha512-wNcy4NvjMYL8gogWWYAO7ZFWFfHcbdbE57tZO8e4cbpj8tfUcwrwqSl3ad8HxpYWCdXcJUCeKKZS62Av1affwQ==",
+          "dev": true
+        },
         "yargs": {
           "version": "15.3.1",
           "resolved": "https://registry.npmjs.org/yargs/-/yargs-15.3.1.tgz",
@@ -18834,11 +18842,6 @@
             "strip-ansi": "^6.0.0"
           }
         },
-        "y18n": {
-          "version": "5.0.5",
-          "resolved": "https://registry.npmjs.org/y18n/-/y18n-5.0.5.tgz",
-          "integrity": "sha512-hsRUr4FFrvhhRH12wOdfs38Gy7k2FFzB9qgN9v3aLykRq0dRcdcpz5C9FxdS2NuhOrI/628b/KSTJ3rwHysYSg=="
-        },
         "yargs": {
           "version": "16.2.0",
           "resolved": "https://registry.npmjs.org/yargs/-/yargs-16.2.0.tgz",
@@ -19642,10 +19645,9 @@
       "dev": true
     },
     "y18n": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.0.tgz",
-      "integrity": "sha512-r9S/ZyXu/Xu9q1tYlpsLIsa3EeLXXk0VwlxqTcFRfg9EhMW+17kbt9G0NrgCmhGb5vT2hyhJZLfDGx+7+5Uj/w==",
-      "dev": true
+      "version": "5.0.5",
+      "resolved": "https://registry.npmjs.org/y18n/-/y18n-5.0.5.tgz",
+      "integrity": "sha512-hsRUr4FFrvhhRH12wOdfs38Gy7k2FFzB9qgN9v3aLykRq0dRcdcpz5C9FxdS2NuhOrI/628b/KSTJ3rwHysYSg=="
     },
     "yallist": {
       "version": "4.0.0",
@@ -19812,6 +19814,12 @@
             "strip-ansi": "^5.0.0"
           }
         },
+        "y18n": {
+          "version": "4.0.1",
+          "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.1.tgz",
+          "integrity": "sha512-wNcy4NvjMYL8gogWWYAO7ZFWFfHcbdbE57tZO8e4cbpj8tfUcwrwqSl3ad8HxpYWCdXcJUCeKKZS62Av1affwQ==",
+          "dev": true
+        },
         "yargs-parser": {
           "version": "13.1.2",
           "resolved": "https://registry.npmjs.org/yargs-parser/-/yargs-parser-13.1.2.tgz",
@@ -19941,6 +19949,12 @@
             "strip-ansi": "^5.0.0"
           }
         },
+        "y18n": {
+          "version": "4.0.1",
+          "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.1.tgz",
+          "integrity": "sha512-wNcy4NvjMYL8gogWWYAO7ZFWFfHcbdbE57tZO8e4cbpj8tfUcwrwqSl3ad8HxpYWCdXcJUCeKKZS62Av1affwQ==",
+          "dev": true
+        },
         "yargs": {
           "version": "14.2.3",
           "resolved": "https://registry.npmjs.org/yargs/-/yargs-14.2.3.tgz",

src/providers/instagram.js

@@ -45,6 +45,7 @@ export default function Instagram (options) {
         email: null,
         image: null
       }
-    }
+    },
+    ...options
   }
 }

src/server/index.js

@@ -7,7 +7,7 @@ import * as defaultEvents from './lib/default-events'
 import * as defaultCallbacks from './lib/default-callbacks'
 import parseProviders from './lib/providers'
 import callbackUrlHandler from './lib/callback-url-handler'
-import extendRes from './lib/extend-req'
+import extendRes from './lib/extend-res'
 import * as routes from './routes'
 import renderPage from './pages'
 import csrfTokenHandler from './lib/csrf-token-handler'
@@ -79,6 +79,10 @@ async function NextAuthHandler (req, res, userOptions) {
       provider.protection = 'state' // Default to state, as we did in 3.1 REVIEW: should we use "pkce" or "none" as default?
     }
 
+    if (typeof provider?.protection === 'string') {
+      provider.protection = [provider.protection]
+    }
+
     const maxAge = 30 * 24 * 60 * 60 // Sessions expire after 30 days of being idle
 
     // Parse database / adapter

src/server/lib/oauth/client.js

@@ -136,7 +136,7 @@ async function getOAuth2AccessToken (code, provider, codeVerifier) {
     headers.Authorization = `Bearer ${code}`
   }
 
-  if (provider.protection === 'pkce') {
+  if (provider.protection.includes('pkce')) {
     params.code_verifier = codeVerifier
   }
 

src/server/lib/oauth/pkce-handler.js

@@ -16,7 +16,7 @@ const PKCE_MAX_AGE = 60 * 15 // 15 minutes in seconds
 export async function handleCallback (req, res) {
   const { cookies, provider, baseUrl, basePath } = req.options
   try {
-    if (provider.protection !== 'pkce') { // Provider does not support PKCE, nothing to do.
+    if (!provider.protection.includes('pkce')) { // Provider does not support PKCE, nothing to do.
       return
     }
 
@@ -50,7 +50,7 @@ export async function handleCallback (req, res) {
 export async function handleSignin (req, res) {
   const { cookies, provider, baseUrl, basePath } = req.options
   try {
-    if (provider.protection !== 'pkce') { // Provider does not support PKCE, nothing to do.
+    if (!provider.protection.includes('pkce')) { // Provider does not support PKCE, nothing to do.
       return
     }
     // Started login flow, add generated pkce to req.options and (encrypted) code_verifier to a cookie

src/server/lib/oauth/state-handler.js

@@ -12,7 +12,7 @@ import { OAuthCallbackError } from '../../../lib/errors'
 export async function handleCallback (req, res) {
   const { csrfToken, provider, baseUrl, basePath } = req.options
   try {
-    if (provider.protection !== 'state') { // Provider does not support state, nothing to do.
+    if (!provider.protection.includes('state')) { // Provider does not support state, nothing to do.
       return
     }
 
@@ -41,7 +41,7 @@ export async function handleCallback (req, res) {
 export async function handleSignin (req, res) {
   const { provider, baseUrl, basePath, csrfToken } = req.options
   try {
-    if (provider.protection !== 'state') { // Provider does not support state, nothing to do.
+    if (!provider.protection.includes('state')) { // Provider does not support state, nothing to do.
       return
     }
 

www/docs/configuration/callbacks.md

@@ -79,7 +79,7 @@ When using NextAuth.js without a database, the user object it will always be a p
 :::
 
 :::tip
-If you only want to allow users who already have accounts in the database to sign in, you can check for the existance of a `user.id` property and reject any sign in attempts from accounts that do not have one.
+If you only want to allow users who already have accounts in the database to sign in, you can check for the existence of a `user.id` property and reject any sign in attempts from accounts that do not have one.
 
 If you are using NextAuth.js without database and want to control who can sign in, you can check their email address or profile against a hard coded list in the `signIn()` callback.
 :::

www/docs/configuration/options.md

@@ -18,7 +18,7 @@ If your Next.js application uses a custom base path, specify the route to the AP
 _e.g. `NEXTAUTH_URL=https://example.com/custom-route/api/auth`_
 
 :::tip
-To set environment variables on Vercel, you can use the [dashboard](https://vercel.com/dashboard) or the `now env` command.
+To set environment variables on Vercel, you can use the [dashboard](https://vercel.com/dashboard) or the `vercel env` command.
 :::
 
 ### NEXTAUTH_URL_INTERNAL
@@ -121,11 +121,29 @@ By default JSON Web Tokens are signed (JWS) but not encrypted (JWE), as JWT encr
 jwt: {
   // A secret to use for key generation - you should set this explicitly
   // Defaults to NextAuth.js secret if not explicitly specified.
+  // This is used to generate the actual signingKey and produces a warning
+  // message if not defined explicitly.
   // secret: 'INp8IvdIyeMcoGAgFGoA61DdBglwwSqnXJZkgz8PSnw',
   
+  // You can generate a signing key using `jose newkey -s 512 -t oct -a HS512`
+  // This gives you direct knowledge of the key used to sign the token so you can use it
+  // to authenticate indirectly (eg. to a database driver)
+  // signingKey: {"kty":"oct","kid":"Dl893BEV-iVE-x9EC52TDmlJUgGm9oZ99_ZL025Hc5Q","alg":"HS512","k":"K7QqRmJOKRK2qcCKV_pi9PSBv3XP0fpTu30TP8xn4w01xR3ZMZM38yL2DnTVPVw6e4yhdh0jtoah-i4c_pZagA"},
+  
+  // If you chose something other than the default algorithm for the signingKey (HS512)
+  // you also need to configure the algorithm
+  // verificationOptions: {
+  //    algorithms: ['HS256']
+  // },
+  
   // Set to true to use encryption. Defaults to false (signing only).
   // encryption: true,
-
+  // encryptionKey: "",
+  // decryptionKey = encryptionKey,
+  // decryptionOptions = {
+  //    algorithms: ['A256GCM']
+  // },
+  
   // You can define your own encode/decode functions for signing and encryption
   // if you want to override the default behaviour.
   // async encode({ secret, token, maxAge }) {},

www/docs/configuration/pages.md

@@ -42,11 +42,22 @@ export default function SignIn({ providers }) {
   )
 }
 
+// This is the recommended way for Next.js 9.3 or newer
+export async function getServerSideProps(context){
+  const providers = await providers()
+  return {
+    props: { providers }
+  }
+}
+
+/*
+// If older than Next.js 9.3
 SignIn.getInitialProps = async () => {
   return {
     providers: await providers()
   }
 }
+*/
 ```
 
 ### Email Sign in
@@ -54,7 +65,7 @@ SignIn.getInitialProps = async () => {
 If you create a custom sign in form for email sign in, you will need to submit both fields for the **email** address and **csrfToken** from **/api/auth/csrf** in a POST request to **/api/auth/signin/email**.
 
 ```jsx title="pages/auth/email-signin.js"
-import { csrfToken } from 'next-auth/client'
+import { getCsrfToken } from 'next-auth/client'
 
 export default function SignIn({ csrfToken }) {
   return (
@@ -62,18 +73,29 @@ export default function SignIn({ csrfToken }) {
       <input name='csrfToken' type='hidden' defaultValue={csrfToken}/>
       <label>
         Email address
-        <input type='text' id='email' name='email'/>
+        <input type='email' id='email' name='email'/>
       </label>
       <button type='submit'>Sign in with Email</button>
     </form>
   )
 }
 
-SignIn.getInitialProps = async (context) => {
+// This is the recommended way for Next.js 9.3 or newer
+export async function getServerSideProps(context){
+  const csrfToken = await getCsrfToken(context)
   return {
-    csrfToken: await csrfToken(context)
+    props: { csrfToken }
   }
 }
+
+/*
+// If older than Next.js 9.3
+SignIn.getInitialProps = async (context) => {
+  return {
+    csrfToken: await getCsrfToken(context)
+  }
+}
+*/
 ```
 
 You can also use the `signIn()` function which will handle obtaining the CSRF token for you:
@@ -87,7 +109,7 @@ signIn('email', { email: 'jsmith@example.com' })
 If you create a sign in form for credentials based authentication, you will need to pass a **csrfToken** from **/api/auth/csrf** in a POST request to **/api/auth/callback/credentials**.
 
 ```jsx title="pages/auth/credentials-signin.js"
-import { csrfToken } from 'next-auth/client'
+import { getCsrfToken } from 'next-auth/client'
 
 export default function SignIn({ csrfToken }) {
   return (
@@ -99,18 +121,30 @@ export default function SignIn({ csrfToken }) {
       </label>
       <label>
         Password
-        <input name='password' type='text'/>
+        <input name='password' type='password'/>
       </label>
       <button type='submit'>Sign in</button>
     </form>
   )
 }
 
-SignIn.getInitialProps = async (context) => {
+// This is the recommended way for Next.js 9.3 or newer
+export async function getServerSideProps(context) {
   return {
-    csrfToken: await csrfToken(context)
+    props: {
+      csrfToken: await getCsrfToken(context)
+    }
   }
 }
+
+/*
+// If older than Next.js 9.3
+SignIn.getInitialProps = async (context) => {
+  return {
+    csrfToken: await getCsrfToken(context)
+  }
+}
+*/
 ```
 
 You can also use the `signIn()` function which will handle obtaining the CSRF token for you:

www/docs/configuration/providers.md

@@ -56,15 +56,11 @@ NextAuth.js is designed to work with any OAuth service, it supports OAuth 1.0, 1
 
 <Image src="/img/signin.png" alt="Signin Screenshot" />
 
-:::tip
-If you want to create a custom sign in link you can link to **/api/auth/signin/[provider]** which will sign in the user in directly with that provider.
-:::
-
 ### Using a custom provider
 
 You can use an OAuth provider that isn't built-in by using a custom object.
 
-As an example of what this looks like, this is the the provider object returned for the Google provider:
+As an example of what this looks like, this is the provider object returned for the Google provider:
 
 ```js
 {
@@ -145,7 +141,7 @@ You can look at the existing built-in providers for inspiration.
 |       profile       |       An callback returning an object with the user's info       |            `object`             |    No    |
 |       idToken       |   Set to `true` for services that use ID Tokens (e.g. OpenID)    |            `boolean`            |    No    |
 |       headers       |      Any headers that should be sent to the OAuth provider       |            `object`             |    No    |
-|     protection      | Additional security for OAuth login flows (defaults to `state`)  |     `pkce`, `state`, `none`     |    No    |
+|     protection      | Additional security for OAuth login flows (defaults to `state`)  |`[pkce]`,`[state]`,`[pkce,state]`|    No    |
 |        state        | Same as `protection: "state"`. Being deprecated, use protection. |            `boolean`            |    No    |
 
 ## Sign in with Email

www/docs/errors.md

@@ -76,13 +76,31 @@ In _most cases_ it does not make sense to specify a database in NextAuth.js opti
 The provider you tried to use failed when setting [PKCE or Proof Key for Code Exchange](https://tools.ietf.org/html/rfc7636#section-4.2).
 The `code_verifier` is saved in a cookie called (by default) `__Secure-next-auth.pkce.code_verifier` which expires after 15 minutes.
 Check if `cookies.pkceCodeVerifier` is configured correctly. The default `code_challenge_method` is `"S256"`. This is currently not configurable to `"plain"`, as it is not recommended, and in most cases it is only supported for backward compatibility.
-
 ---
 
 ### Session Handling
 
 #### JWT_SESSION_ERROR
 
+https://next-auth.js.org/errors#jwt_session_error JWKKeySupport: the key does not support HS512 verify algorithm
+
+The algorithm used for generating your key isn't listed as supported. You can generate a HS512 key using
+
+````
+  jose newkey -s 512 -t oct -a HS512
+````
+
+If you are unable to use an HS512 key (for example to interoperate with other services) you can define what is supported using
+
+````
+  jwt: {
+    signingKey: {"kty":"oct","kid":"--","alg":"HS256","k":"--"}
+    verificationOptions: {
+      algorithms: ["HS256"]
+    }
+  }
+````
+
 #### SESSION_ERROR
 
 ---
@@ -139,4 +157,4 @@ Check your mail server configuration.
 
 This error happens when `[...nextauth].js` file is not found inside `pages/api/auth`.
 
-Make sure the file is there and the filename is written correctly.
+Make sure the file is there and the filename is written correctly.

www/docs/providers/email.md

@@ -91,7 +91,7 @@ providers: [
   Providers.Email({
     server: process.env.EMAIL_SERVER, 
     from: process.env.EMAIL_FROM,
-    sendVerificationRequest: ({ identifier: email, url, token, site, provider }) => { /* your function */ }
+    sendVerificationRequest: ({ identifier: email, url, token, baseUrl, provider }) => { /* your function */ }
   })
 ]
 ```

www/docs/schemas/adapters.md

@@ -185,7 +185,7 @@ Once you have saved your schema, use the Prisma CLI to generate the Prisma Clien
 npx prisma generate
 ```
 
-To configure you database to use the new schema (i.e. create tables and columns) use the `primsa migrate` command:
+To configure you database to use the new schema (i.e. create tables and columns) use the `prisma migrate` command:
 
 ```
 npx prisma migrate dev --preview-feature