fix(providers): make string endpoint handlers overrideable (#2842)

* chore: remove `console.log`

* chore(ts): improve `InternalProvider` type

* refactor(ts): convert some files to TypeScript

* fix(providers): make string endpoint handlers overrideable

Author: balazsorban44

src/lib/types.ts

@@ -11,22 +11,38 @@ import type {
   Awaitable,
 } from ".."
 
-import type { Provider } from "../providers"
+import type {
+  OAuthConfig,
+  EmailConfig,
+  CredentialsConfig,
+  AuthorizationEndpointHandler,
+  TokenEndpointHandler,
+  UserinfoEndpointHandler,
+  ProviderType,
+} from "../providers"
 import type { JWTOptions } from "../jwt"
 import type { Adapter } from "../adapters"
 
 // Below are types that are only supposed be used by next-auth internally
 
 /** @internal */
-export type InternalProvider = Provider & {
+export type InternalProvider<T extends ProviderType = any> = (T extends "oauth"
+  ? Omit<OAuthConfig<any>, "authorization" | "token" | "userinfo"> & {
+      authorization: AuthorizationEndpointHandler
+      token: TokenEndpointHandler
+      userinfo: UserinfoEndpointHandler
+    }
+  : T extends "email"
+  ? EmailConfig
+  : T extends "credentials"
+  ? CredentialsConfig
+  : never) & {
   signinUrl: string
   callbackUrl: string
 }
 
 /** @internal */
-export interface InternalOptions<
-  P extends InternalProvider = InternalProvider
-> {
+export interface InternalOptions<T extends ProviderType = any> {
   providers: InternalProvider[]
   baseUrl: string
   basePath: string
@@ -39,7 +55,9 @@ export interface InternalOptions<
     | "callback"
     | "verify-request"
     | "error"
-  provider: P
+  provider: T extends string
+    ? InternalProvider<T>
+    : InternalProvider<T> | undefined
   csrfToken?: string
   csrfTokenVerified?: boolean
   secret: string

src/providers/email.ts

@@ -72,7 +72,6 @@ export default function Email(options: EmailUserConfig): EmailConfig {
       provider: { server, from },
     }) {
       const { host } = new URL(url)
-      console.log(server)
       const transport = createTransport(server)
       await transport.sendMail({
         to: email,

src/providers/oauth.ts

@@ -50,9 +50,39 @@ interface AdvancedEndpointHandler<P extends UrlParams, C, R> {
 }
 
 /** Either an URL (containing all the parameters) or an object with more granular control. */
-type EndpointHandler<P extends UrlParams, C = any, R = any> =
-  | string
-  | AdvancedEndpointHandler<P, C, R>
+export type EndpointHandler<
+  P extends UrlParams,
+  C = any,
+  R = any
+> = AdvancedEndpointHandler<P, C, R>
+
+export type AuthorizationEndpointHandler =
+  EndpointHandler<AuthorizationParameters>
+
+export type TokenEndpointHandler = EndpointHandler<
+  UrlParams,
+  {
+    /**
+     * Parameters extracted from the request to the `/api/auth/callback/:providerId` endpoint.
+     * Contains params like `state`.
+     */
+    params: CallbackParamsType
+    /**
+     * When using this custom flow, make sure to do all the necessary security checks.
+     * Thist object contains parameters you have to match against the request to make sure it is valid.
+     */
+    checks: OAuthChecks
+  },
+  {
+    tokens: TokenSet
+  }
+>
+
+export type UserinfoEndpointHandler = EndpointHandler<
+  UrlParams,
+  { tokens: TokenSet },
+  Profile
+>
 
 export interface OAuthConfig<P> extends CommonProviderOptions, PartialIssuer {
   /**
@@ -70,40 +100,11 @@ export interface OAuthConfig<P> extends CommonProviderOptions, PartialIssuer {
    *
    * [Authorization endpoint](https://datatracker.ietf.org/doc/html/rfc6749#section-3.1)
    */
-  authorization?: EndpointHandler<AuthorizationParameters>
-  /**
-   * Endpoint that returns OAuth 2/OIDC tokens and information about them.
-   * This includes `access_token`, `id_token`, `refresh_token`, etc.
-   *
-   * [Token endpoint](https://datatracker.ietf.org/doc/html/rfc6749#section-3.2)
-   */
-  token?: EndpointHandler<
-    UrlParams,
-    {
-      /**
-       * Parameters extracted from the request to the `/api/auth/callback/:providerId` endpoint.
-       * Contains params like `state`.
-       */
-      params: CallbackParamsType
-      /**
-       * When using this custom flow, make sure to do all the necessary security checks.
-       * Thist object contains parameters you have to match against the request to make sure it is valid.
-       */
-      checks: OAuthChecks
-    },
-    { tokens: TokenSet }
-  >
-  /**
-   * When using an OAuth 2 provider, the user information must be requested
-   * through an additional request from the userinfo endpoint.
-   *
-   * [Userinfo endpoint](https://www.oauth.com/oauth2-servers/signing-in-with-google/verifying-the-user-info)
-   */
-  userinfo?: EndpointHandler<UrlParams, { tokens: TokenSet }, Profile>
+  authorization?: string | AuthorizationEndpointHandler
+  token?: string | TokenEndpointHandler
+  userinfo?: string | UserinfoEndpointHandler
   type: "oauth"
   version?: string
-  accessTokenUrl?: string
-  requestTokenUrl?: string
   profile?: (profile: P, tokens: TokenSet) => Awaitable<User & { id: string }>
   checks?: ChecksType | ChecksType[]
   clientId?: string
@@ -133,6 +134,11 @@ export interface OAuthConfig<P> extends CommonProviderOptions, PartialIssuer {
    * with the default configuration.
    */
   options?: OAuthUserConfig<P>
+
+  // These are kept around for backwards compatibility with OAuth 1.x
+  accessTokenUrl?: string
+  requestTokenUrl?: string
+  encoding?: string
 }
 
 export type OAuthUserConfig<P> = Omit<

src/providers/spotify.js renamed to src/providers/spotify.ts

@@ -1,5 +1,18 @@
-/** @type {import(".").OAuthProvider} */
-export default function Spotify(options) {
+import { OAuthConfig, OAuthUserConfig } from "."
+
+export interface SpotifyImage {
+  url: string
+}
+
+export interface SpotifyProfile {
+  id: string
+  display_name: string
+  email: string
+  images: SpotifyImage[]
+}
+export default function Spotify<P extends Record<string, any> = SpotifyProfile>(
+  options: OAuthUserConfig<P>
+): OAuthConfig<P> {
   return {
     id: "spotify",
     name: "Spotify",

src/server/index.ts

@@ -73,33 +73,23 @@ async function NextAuthHandler(
 
   const secret = createSecret({ userOptions, basePath, baseUrl })
 
-  const providers = parseProviders({
+  const { providers, provider } = parseProviders({
     providers: userOptions.providers,
     base: `${baseUrl}${basePath}`,
+    providerId: providerId as string | undefined,
   })
 
-  const provider = providers.find(({ id }) => id === providerId)
-
-  // Checks only work on OAuth 2.x + OIDC providers
-  if (
-    provider?.type === "oauth" &&
-    !provider.version?.startsWith("1.") &&
-    !provider.checks
-  ) {
-    provider.checks = ["state"]
-  }
-
   const maxAge = 30 * 24 * 60 * 60 // Sessions expire after 30 days of being idle by default
 
   // User provided options are overriden by other options,
   // except for the options with special handling above
-  const options: InternalOptions<any> = {
+  const options: InternalOptions = {
     debug: false,
     pages: {},
     theme: {
       colorScheme: "auto",
-      logo: '',
-      brandColor: ''
+      logo: "",
+      brandColor: "",
     },
     // Custom options override defaults
     ...userOptions,

src/server/lib/email/signin.ts

@@ -1,6 +1,5 @@
 import { randomBytes } from "crypto"
-import { EmailConfig } from "src/providers"
-import { InternalOptions, InternalProvider } from "src/lib/types"
+import { InternalOptions } from "src/lib/types"
 import { hashToken } from "../utils"
 
 /**
@@ -9,7 +8,7 @@ import { hashToken } from "../utils"
  */
 export default async function email(
   identifier: string,
-  options: InternalOptions<EmailConfig & InternalProvider>
+  options: InternalOptions<"email">
 ) {
   const { baseUrl, basePath, adapter, provider, logger, callbackUrl } = options
 

src/server/lib/oauth/client-legacy.js renamed to src/server/lib/oauth/client-legacy.ts

@@ -2,29 +2,29 @@
 // We have the intentions to provide only minor fixes for this in the future.
 
 import { OAuth } from "oauth"
+import { InternalOptions } from "src/lib/types"
 
 /**
  * Client supporting OAuth 1.x
- * @param {import("src/lib/types").InternalOptions} options
  */
-export function oAuth1Client(options) {
-  /** @type {import("src/providers").OAuthConfig} */
+export function oAuth1Client(options: InternalOptions<"oauth">) {
   const provider = options.provider
 
   const oauth1Client = new OAuth(
-    provider.requestTokenUrl,
-    provider.accessTokenUrl,
-    provider.clientId,
-    provider.clientSecret,
-    provider.version || "1.0",
+    provider.requestTokenUrl as string,
+    provider.accessTokenUrl as string,
+    provider.clientId as string,
+    provider.clientSecret as string,
+    provider.version ?? "1.0",
     provider.callbackUrl,
-    provider.encoding || "HMAC-SHA1"
+    provider.encoding ?? "HMAC-SHA1"
   )
 
   // Promisify get()  for OAuth1
   const originalGet = oauth1Client.get.bind(oauth1Client)
-  oauth1Client.get = (...args) => {
-    return new Promise((resolve, reject) => {
+  // @ts-expect-error
+  oauth1Client.get = async (...args) => {
+    return await new Promise((resolve, reject) => {
       originalGet(...args, (error, result) => {
         if (error) {
           return reject(error)
@@ -36,8 +36,8 @@ export function oAuth1Client(options) {
   // Promisify getOAuth1AccessToken()  for OAuth1
   const originalGetOAuth1AccessToken =
     oauth1Client.getOAuthAccessToken.bind(oauth1Client)
-  oauth1Client.getOAuthAccessToken = (...args) => {
-    return new Promise((resolve, reject) => {
+  oauth1Client.getOAuthAccessToken = async (...args: any[]) => {
+    return await new Promise((resolve, reject) => {
       originalGetOAuth1AccessToken(
         ...args,
         (error, oauth_token, oauth_token_secret) => {
@@ -52,8 +52,8 @@ export function oAuth1Client(options) {
 
   const originalGetOAuthRequestToken =
     oauth1Client.getOAuthRequestToken.bind(oauth1Client)
-  oauth1Client.getOAuthRequestToken = (params = {}) => {
-    return new Promise((resolve, reject) => {
+  oauth1Client.getOAuthRequestToken = async (params = {}) => {
+    return await new Promise((resolve, reject) => {
       originalGetOAuthRequestToken(
         params,
         (error, oauth_token, oauth_token_secret, params) => {

src/server/lib/oauth/client.js renamed to src/server/lib/oauth/client.ts

@@ -1,27 +1,25 @@
 import { Issuer } from "openid-client"
+import { InternalOptions } from "src/lib/types"
 
 /**
  * NOTE: We can add auto discovery of the provider's endpoint
  * that requires only one endpoint to be specified by the user.
  * Check out `Issuer.discover`
  *
  * Client supporting OAuth 2.x and OIDC
- * @param {import("src/lib/types").InternalOptions} options
  */
-export async function openidClient(options) {
-  /** @type {import("src/providers").OAuthConfig} */
+export async function openidClient(options: InternalOptions<"oauth">) {
   const provider = options.provider
 
   let issuer
   if (provider.wellKnown) {
     issuer = await Issuer.discover(provider.wellKnown)
   } else {
     issuer = new Issuer({
-      issuer: provider.issuer,
-      authorization_endpoint:
-        provider.authorization.url ?? provider.authorization,
-      token_endpoint: provider.token.url ?? provider.token,
-      userinfo_endpoint: provider.userinfo.url ?? provider.userinfo,
+      issuer: provider.issuer as string,
+      authorization_endpoint: provider.authorization.url,
+      token_endpoint: provider.token.url,
+      userinfo_endpoint: provider.userinfo.url,
     })
   }