fix(core): Prevent email link sign in completion from double error handling

examples/react/src/routes.ts

@@ -64,7 +64,7 @@ export const routes = [
   {
     name: "Forgot Password Screen",
     description: "A screen allowing a user to reset their password",
-    path: "/screens/forgot-password-screen",
+    path: "/screens/forgot-password-auth-screen",
     component: ForgotPasswordAuthScreenPage,
   },
   {

examples/react/src/screens/sign-in-auth-screen-w-handlers.tsx

@@ -24,7 +24,7 @@ export default function SignInAuthScreenWithHandlersPage() {
   return (
     <SignInAuthScreen
       onForgotPasswordClick={() => {
-        navigate("/screen/forgot-password-auth-screen");
+        navigate("/screens/forgot-password-auth-screen");
       }}
       onSignUpClick={() => {
         navigate("/screens/sign-up-auth-screen");

packages/core/src/auth.test.ts

@@ -1257,8 +1257,6 @@ describe("completeEmailLinkSignIn", () => {
 
     expect(_isSignInWithEmailLink).toHaveBeenCalledWith(mockUI.auth, currentUrl);
     expect(result).toBeNull();
-
-    expect(vi.mocked(mockUI.setState).mock.calls).toEqual([["idle"]]);
   });
 
   it("should return null when no email is stored in localStorage", async () => {
@@ -1271,7 +1269,6 @@ describe("completeEmailLinkSignIn", () => {
 
     expect(_isSignInWithEmailLink).toHaveBeenCalledWith(mockUI.auth, currentUrl);
     expect(result).toBeNull();
-    expect(vi.mocked(mockUI.setState).mock.calls).toEqual([["idle"]]);
   });
 
   it("should complete email link sign-in with no behavior", async () => {
@@ -1294,7 +1291,8 @@ describe("completeEmailLinkSignIn", () => {
     expect(EmailAuthProvider.credentialWithLink).toHaveBeenCalledWith(email, currentUrl);
     expect(_signInWithCredential).toHaveBeenCalledWith(mockUI.auth, emailLinkCredential);
     expect(result).toBe(mockCredential);
-    expect(vi.mocked(mockUI.setState).mock.calls).toEqual([["pending"], ["pending"], ["idle"], ["idle"]]);
+
+    expect(vi.mocked(mockUI.setState).mock.calls).toEqual([["pending"], ["idle"]]);
     expect(window.localStorage.getItem("emailForSignIn")).toBeNull();
   });
 
@@ -1315,16 +1313,18 @@ describe("completeEmailLinkSignIn", () => {
     const result = await completeEmailLinkSignIn(mockUI, currentUrl);
 
     expect(_isSignInWithEmailLink).toHaveBeenCalledWith(mockUI.auth, currentUrl);
+    // Behavior is checked by signInWithCredential (called via signInWithEmailLink)
     expect(hasBehavior).toHaveBeenCalledWith(mockUI, "autoUpgradeAnonymousCredential");
     expect(EmailAuthProvider.credentialWithLink).toHaveBeenCalledWith(email, currentUrl);
     expect(getBehavior).toHaveBeenCalledWith(mockUI, "autoUpgradeAnonymousCredential");
     expect(mockBehavior).toHaveBeenCalledWith(mockUI, emailLinkCredential);
     expect(result).toBe(mockResult);
+    // State is managed by signInWithCredential
     expect(vi.mocked(mockUI.setState).mock.calls).toEqual([["pending"], ["idle"]]);
     expect(window.localStorage.getItem("emailForSignIn")).toBeNull();
   });
 
-  it("should fall back to signInWithEmailLink when autoUpgradeAnonymousCredential behavior returns undefined", async () => {
+  it("should fall back to _signInWithCredential when autoUpgradeAnonymousCredential behavior returns undefined", async () => {
     const mockUI = createMockUI();
     const currentUrl = "https://example.com/auth?oobCode=abc123";
     const email = "test@example.com";
@@ -1342,17 +1342,19 @@ describe("completeEmailLinkSignIn", () => {
     const result = await completeEmailLinkSignIn(mockUI, currentUrl);
 
     expect(_isSignInWithEmailLink).toHaveBeenCalledWith(mockUI.auth, currentUrl);
+    // Behavior is checked by signInWithCredential (called via signInWithEmailLink)
     expect(hasBehavior).toHaveBeenCalledWith(mockUI, "autoUpgradeAnonymousCredential");
     expect(EmailAuthProvider.credentialWithLink).toHaveBeenCalledWith(email, currentUrl);
     expect(getBehavior).toHaveBeenCalledWith(mockUI, "autoUpgradeAnonymousCredential");
     expect(mockBehavior).toHaveBeenCalledWith(mockUI, emailLinkCredential);
     expect(_signInWithCredential).toHaveBeenCalledWith(mockUI.auth, emailLinkCredential);
     expect(result).toBe(mockResult);
-    expect(vi.mocked(mockUI.setState).mock.calls).toEqual([["pending"], ["pending"], ["idle"], ["idle"]]);
+    // State is managed by signInWithCredential
+    expect(vi.mocked(mockUI.setState).mock.calls).toEqual([["pending"], ["idle"]]);
     expect(window.localStorage.getItem("emailForSignIn")).toBeNull();
   });
 
-  it("should call handleFirebaseError if an error is thrown", async () => {
+  it("should propagate error from signInWithEmailLink", async () => {
     const mockUI = createMockUI();
     const currentUrl = "https://example.com/auth?oobCode=abc123";
     const email = "test@example.com";
@@ -1364,16 +1366,21 @@ describe("completeEmailLinkSignIn", () => {
     vi.mocked(hasBehavior).mockReturnValue(false);
     vi.mocked(EmailAuthProvider.credentialWithLink).mockReturnValue(emailLinkCredential);
     vi.mocked(_signInWithCredential).mockRejectedValue(error);
+    // handleFirebaseError throws, so we need to catch it
+    vi.mocked(handleFirebaseError).mockImplementation(() => {
+      throw new Error("Handled error");
+    });
 
-    const result = await completeEmailLinkSignIn(mockUI, currentUrl);
+    await expect(completeEmailLinkSignIn(mockUI, currentUrl)).rejects.toThrow("Handled error");
 
+    // Error is handled by signInWithCredential (called via signInWithEmailLink)
     expect(handleFirebaseError).toHaveBeenCalledWith(mockUI, error);
-    expect(vi.mocked(mockUI.setState).mock.calls).toEqual([["pending"], ["pending"], ["idle"], ["idle"]]);
+    // State is managed by signInWithCredential
+    expect(vi.mocked(mockUI.setState).mock.calls).toEqual([["pending"], ["idle"]]);
     expect(window.localStorage.getItem("emailForSignIn")).toBeNull();
-    expect(result).toBeUndefined();
   });
 
-  it("should call handleFirebaseError if autoUpgradeAnonymousCredential behavior throws error", async () => {
+  it("should propagate error when autoUpgradeAnonymousCredential behavior throws", async () => {
     const mockUI = createMockUI();
     const currentUrl = "https://example.com/auth?oobCode=abc123";
     const email = "test@example.com";
@@ -1386,13 +1393,18 @@ describe("completeEmailLinkSignIn", () => {
     vi.mocked(EmailAuthProvider.credentialWithLink).mockReturnValue(emailLinkCredential);
     const mockBehavior = vi.fn().mockRejectedValue(error);
     vi.mocked(getBehavior).mockReturnValue(mockBehavior);
+    // handleFirebaseError throws, so we need to catch it
+    vi.mocked(handleFirebaseError).mockImplementation(() => {
+      throw new Error("Handled error");
+    });
 
-    const result = await completeEmailLinkSignIn(mockUI, currentUrl);
+    await expect(completeEmailLinkSignIn(mockUI, currentUrl)).rejects.toThrow("Handled error");
 
+    // Error is handled by signInWithCredential (called via signInWithEmailLink)
     expect(handleFirebaseError).toHaveBeenCalledWith(mockUI, error);
+    // State is managed by signInWithCredential
     expect(vi.mocked(mockUI.setState).mock.calls).toEqual([["pending"], ["idle"]]);
     expect(window.localStorage.getItem("emailForSignIn")).toBeNull();
-    expect(result).toBeUndefined();
   });
 
   it("should clear email from localStorage even when error occurs", async () => {
@@ -1407,9 +1419,14 @@ describe("completeEmailLinkSignIn", () => {
     vi.mocked(hasBehavior).mockReturnValue(false);
     vi.mocked(EmailAuthProvider.credentialWithLink).mockReturnValue(emailLinkCredential);
     vi.mocked(_signInWithCredential).mockRejectedValue(error);
+    // handleFirebaseError throws, but finally block should still run
+    vi.mocked(handleFirebaseError).mockImplementation(() => {
+      throw new Error("Handled error");
+    });
 
-    await completeEmailLinkSignIn(mockUI, currentUrl);
+    await expect(completeEmailLinkSignIn(mockUI, currentUrl)).rejects.toThrow("Handled error");
 
+    // finally block should still clean up localStorage
     expect(window.localStorage.getItem("emailForSignIn")).toBeNull();
   });
 

packages/core/src/auth.ts

@@ -314,23 +314,10 @@ export async function completeEmailLinkSignIn(ui: FirebaseUI, currentUrl: string
     const email = window.localStorage.getItem("emailForSignIn");
     if (!email) return null;
 
-    setPendingState(ui);
-
-    if (hasBehavior(ui, "autoUpgradeAnonymousCredential")) {
-      const emailLinkCredential = EmailAuthProvider.credentialWithLink(email, currentUrl);
-      const credential = await getBehavior(ui, "autoUpgradeAnonymousCredential")(ui, emailLinkCredential);
-
-      if (credential) {
-        return handlePendingCredential(ui, credential);
-      }
-    }
-
+    // signInWithEmailLink handles behavior checks, credential creation, and error handling
     const result = await signInWithEmailLink(ui, email, currentUrl);
     return handlePendingCredential(ui, result);
-  } catch (error) {
-    handleFirebaseError(ui, error);
   } finally {
-    ui.setState("idle");
     window.localStorage.removeItem("emailForSignIn");
   }
 }

packages/react/src/auth/forms/email-link-auth-form.tsx

@@ -77,14 +77,14 @@ export function useEmailLinkAuthFormCompleteSignIn(onSignIn?: EmailLinkAuthFormP
   useEffect(() => {
     const completeSignIn = async () => {
       const credential = await completeEmailLinkSignIn(ui, window.location.href);
-
       if (credential) {
         onSignIn?.(credential);
       }
     };
 
     void completeSignIn();
-  }, [ui, onSignIn]);
+    // eslint-disable-next-line react-hooks/exhaustive-deps -- TODO(ehesp): ui triggers re-render
+  }, [onSignIn]);
 }
 
 export function EmailLinkAuthForm({ onEmailSent, onSignIn }: EmailLinkAuthFormProps) {

packages/shadcn/src/components/email-link-auth-form.test.tsx

@@ -227,12 +227,10 @@ describe("<EmailLinkAuthForm />", () => {
       </FirebaseUIProvider>
     );
 
-    await act(async () => {
-      // Wait for the useEffect to complete
-      await new Promise((resolve) => setTimeout(resolve, 0));
+    await waitFor(() => {
+      expect(completeEmailLinkSignInMock).toHaveBeenCalled();
     });
 
-    expect(completeEmailLinkSignInMock).toHaveBeenCalledWith(mockUI.get(), window.location.href);
     expect(onSignInMock).toHaveBeenCalledWith(mockCredential);
   });
 });