feat(clerk-expo): Introduce SAML support

.changeset/selfish-worms-switch.md

@@ -0,0 +1,8 @@
+---
+'@clerk/clerk-expo': minor
+---
+
+Introduce support for SSO with SAML
+
+- Introduce `useSSO` hook to support a wider range of SSO flow types
+- Deprecate `useOAuth` in favor of new `useSSO` hook

packages/expo/src/hooks/index.ts

@@ -10,5 +10,6 @@ export {
   useUser,
 } from '@clerk/clerk-react';
 
+export * from './useSSO';
 export * from './useOAuth';
 export * from './useAuth';

packages/expo/src/hooks/useOAuth.ts

@@ -24,6 +24,9 @@ export type StartOAuthFlowReturnType = {
   authSessionResult?: WebBrowser.WebBrowserAuthSessionResult;
 };
 
+/**
+ * @deprecated Use `useSSO` instead
+ */
 export function useOAuth(useOAuthParams: UseOAuthFlowParams) {
   const { strategy } = useOAuthParams || {};
   if (!strategy) {

packages/expo/src/hooks/useSSO.ts

@@ -0,0 +1,98 @@
+import { useSignIn, useSignUp } from '@clerk/clerk-react';
+import type { EnterpriseSSOStrategy, OAuthStrategy, SetActive, SignInResource, SignUpResource } from '@clerk/types';
+import * as AuthSession from 'expo-auth-session';
+import * as WebBrowser from 'expo-web-browser';
+
+import { errorThrower } from '../utils/errors';
+
+export type StartSSOFlowParams = {
+  unsafeMetadata?: SignUpUnsafeMetadata;
+} & (
+  | {
+      strategy: OAuthStrategy;
+    }
+  | {
+      strategy: EnterpriseSSOStrategy;
+      identifier: string;
+    }
+);
+
+export type StartSSOFlowReturnType = {
+  createdSessionId: string | null;
+  authSessionResult?: WebBrowser.WebBrowserAuthSessionResult;
+  setActive?: SetActive;
+  signIn?: SignInResource;
+  signUp?: SignUpResource;
+};
+
+export function useSSO() {
+  const { signIn, setActive, isLoaded: isSignInLoaded } = useSignIn();
+  const { signUp, isLoaded: isSignUpLoaded } = useSignUp();
+
+  async function startSSOFlow(startSSOFlowParams: StartSSOFlowParams): Promise<StartSSOFlowReturnType> {
+    if (!isSignInLoaded || !isSignUpLoaded) {
+      return {
+        createdSessionId: null,
+        signIn,
+        signUp,
+        setActive,
+      };
+    }
+
+    const { strategy, unsafeMetadata } = startSSOFlowParams ?? {};
+
+    /**
+     * Creates a redirect URL based on the application platform
+     * It must be whitelisted, either via Clerk Dashboard, or BAPI, in order
+     * to include the `rotating_token_nonce` on SSO callback
+     * @ref https://clerk.com/docs/reference/backend-api/tag/Redirect-URLs#operation/CreateRedirectURL
+     */
+    const redirectUrl = AuthSession.makeRedirectUri({
+      path: 'sso-callback',
+    });
+
+    await signIn.create({
+      strategy,
+      redirectUrl,
+      ...(startSSOFlowParams.strategy === 'enterprise_sso' ? { identifier: startSSOFlowParams.identifier } : {}),
+    });
+
+    const { externalVerificationRedirectURL } = signIn.firstFactorVerification;
+    if (!externalVerificationRedirectURL) {
+      return errorThrower.throw('Missing external verification redirect URL for SSO flow');
+    }
+
+    const authSessionResult = await WebBrowser.openAuthSessionAsync(externalVerificationRedirectURL.toString());
+    if (authSessionResult.type !== 'success' || !authSessionResult.url) {
+      return {
+        createdSessionId: null,
+        setActive,
+        signIn,
+        signUp,
+      };
+    }
+
+    const params = new URL(authSessionResult.url).searchParams;
+    const rotatingTokenNonce = params.get('rotating_token_nonce') ?? '';
+    await signIn.reload({ rotatingTokenNonce });
+
+    const userNeedsToBeCreated = signIn.firstFactorVerification.status === 'transferable';
+    if (userNeedsToBeCreated) {
+      await signUp.create({
+        transfer: true,
+        unsafeMetadata,
+      });
+    }
+
+    return {
+      createdSessionId: signUp.createdSessionId ?? signIn.createdSessionId,
+      setActive,
+      signIn,
+      signUp,
+    };
+  }
+
+  return {
+    startSSOFlow,
+  };
+}