fix(clerk-js): Don't use ctx SSO url if routing is virtual

.changeset/hot-cats-smell.md

@@ -0,0 +1,5 @@
+---
+'@clerk/clerk-js': patch
+---
+
+Fix issue where the SSO callback URL was incorrectly generated when using the transfer flow within a modal.

packages/clerk-js/src/ui/common/__tests__/redirects.test.ts

@@ -209,8 +209,16 @@ describe('buildSSOCallbackURL(ctx, baseUrl)', () => {
     ).toBe('http://test.host/#/sso-callback?redirect_url=%2Ffoo');
 
     // Custom SSO callback URL in the context
-    expect(buildSSOCallbackURL({ ssoCallbackUrl: 'http://test.host/ctx-sso-callback' })).toBe(
+    expect(buildSSOCallbackURL({ isCombinedFlow: true, ssoCallbackUrl: 'http://test.host/ctx-sso-callback' })).toBe(
       'http://test.host/ctx-sso-callback',
     );
+    // Does not use SSO callback URL from context when routing is virtual
+    expect(
+      buildSSOCallbackURL({
+        isCombinedFlow: true,
+        ssoCallbackUrl: 'http://test.host/ctx-sso-callback',
+        routing: 'virtual',
+      }),
+    ).toBe('http://localhost/#/sso-callback');
   });
 });

packages/clerk-js/src/ui/common/redirects.ts

@@ -54,12 +54,13 @@ export function buildSSOCallbackURL(
   ctx: Partial<SignInContextType | SignUpContextType>,
   baseUrl: string | undefined = '',
 ): string {
+  const { routing, authQueryString, path } = ctx;
   // If the context contains an SSO callback URL, use it instead of building a new one, as it likely contains the
-  // combined flow path.
-  if ('ssoCallbackUrl' in ctx && ctx.ssoCallbackUrl) {
+  // combined flow path. However, if the routing is virtual, the callback URL from context will not have factored in
+  // baseUrl, so we fallback to buildRedirectUrl instead.
+  if (ctx.ssoCallbackUrl && ctx.isCombinedFlow && routing !== 'virtual') {
     return ctx.ssoCallbackUrl;
   }
-  const { routing, authQueryString, path } = ctx;
   return buildRedirectUrl({
     routing,
     baseUrl,