Use state if existing in session

lib/__tests__/sdk/oauth2-flows/AuthorizationCode.spec.ts

@@ -96,6 +96,19 @@ describe('AuthorizationCode', () => {
       const state = searchParams.get('state');
       expect(state).toBe(expectedState);
     });
+
+    it('uses same state to generate authorization URL if existing in session', async () => {
+      const client = new AuthorizationCode(clientConfig, clientSecret);
+      const authURL = await client.createAuthorizationURL(sessionManager);
+      const searchParams = new URLSearchParams(authURL.search);
+      const firstState = searchParams.get('state');
+
+      const authURL2 = await client.createAuthorizationURL(sessionManager);
+      const searchParams2 = new URLSearchParams(authURL2.search);
+      const secondState = searchParams2.get('state');
+
+      expect(firstState).toBe(secondState);
+    });
   });
 
   describe('handleRedirectFromAuthDomain()', () => {

lib/sdk/oauth2-flows/AuthorizationCode.ts

@@ -36,7 +36,12 @@ export class AuthorizationCode extends AuthCodeAbstract {
     sessionManager: SessionManager,
     options: AuthURLOptions = {}
   ): Promise<URL> {
-    this.state = options.state ?? utilities.generateRandomString();
+    this.state =
+      options.state ??
+      ((await sessionManager.getSessionItem(
+        AuthorizationCode.STATE_KEY
+      )) as string) ??
+      utilities.generateRandomString();
     await sessionManager.setSessionItem(AuthorizationCode.STATE_KEY, this.state);
     const authURL = new URL(this.authorizationEndpoint);
     const authParams = this.generateAuthURLParams(options);