fix: redirect required SAML users to SSO

[KJ21-ENG]

Explanation of Change

This PR makes the required-SAML sign-in redirect resilient to the transient account.isLoading value from BeginSignIn.

Previously, SignInPage only initiated required SAML when account.isLoading and account.isSAMLRequired were true in the same render. If the completed BeginSignIn response set isSAMLRequired: true after loading was already cleared, the sign-in page could clear credentials instead of navigating to SAML.

This change:

• Tracks that the current sign-in page observed a pending login attempt, so required SAML can launch after the completed response arrives with isLoading: false.
• Moves required-SAML navigation and stale cleanup out of render and into effects.
• Keeps the stale/reloaded required-SAML cleanup path so persisted required-SAML state does not loop forever.
• Lets native SAML callbacks with credentials.login and shortLivedAuthToken continue even if account.isLoading is true, while guarding duplicate callback consumption locally.

Fixed Issues

$ #92479
PROPOSAL: #92479 (comment)

Tests

1. Open New Expensify on the sign-in page.
2. Use a SAML-required test account/domain.
3. Enter the SAML-required email address and submit.
4. Verify the app navigates to the SAML sign-in flow instead of staying on the password/magic-code path.
5. Verify the user is redirected to the SSO provider.
6. Verify credentials are not cleared before the SAML page can request the IdP URL.
7. On native, complete the SAML browser callback and verify the callback signs in with the short-lived auth token even if account loading state is still true.
8. Verify that no errors appear in the JS console.

Additional local frontend-only verification was performed with an Onyx fixture that simulates a completed BeginSignIn response with account.isSAMLRequired: true and account.isLoading: false.

Offline tests

N/A. SAML sign-in requires network access to request the IdP URL and complete authentication. No offline behavior was changed.

QA Steps

1. Use a SAML-required test account/domain.
2. Open New Expensify on the sign-in page.
3. Enter the SAML-required email address and submit.
4. Verify the app navigates to the SAML sign-in flow and redirects to the SSO provider.
5. Verify the user is not left on the password/magic-code path.
6. Verify the entered login is not cleared before the SAML page can request the IdP URL.
7. On native, complete the SAML browser callback and verify sign-in succeeds.
8. Verify that no errors appear in the JS console.

PR Author Checklist

• I linked the correct issue in the ### Fixed Issues section above
• I wrote clear testing steps that cover the changes made in this PR
  • I added steps for local testing in the Tests section
  • I added steps for the expected offline behavior in the Offline steps section
  • I added steps for Staging and/or Production testing in the QA steps section
  • I added steps to cover failure scenarios (i.e. verify an input displays the correct error message if the entered data is not correct)
  • I turned off my network connection and tested it while offline to ensure it matches the expected behavior (i.e. verify the default avatar icon is displayed if app is offline) (N/A: SAML sign-in requires network access and no offline behavior was changed)
  • I tested this PR with a High Traffic account against the staging or production API to ensure there are no regressions (e.g. long loading states that impact usability). (N/A: this is an unauthenticated SAML sign-in redirect change)
• I included screenshots or videos for tests on all platforms
• I ran the tests on all platforms & verified they passed on:
  • Android: Native
  • Android: mWeb Chrome
  • iOS: Native
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
• I verified there are no console errors (if there's a console error not related to the PR, report it or open an issue for it to be fixed)
• I followed proper code patterns (see Reviewing the code)
  • I verified that any callback methods that were added or modified are named for what the method does and never what callback they handle (i.e. toggleReport and not onIconClick)
  • I verified that comments were added to code that is not self explanatory
  • I verified that any new or modified comments were clear, correct English, and explained "why" the code was doing something instead of only explaining "what" the code was doing.
  • I verified any copy / text shown in the product is localized by adding it to src/languages/* files and using the translation method
  • I verified all numbers, amounts, dates and phone numbers shown in the product are using the localization methods
  • I verified any copy / text that was added to the app is grammatically correct in English. It adheres to proper capitalization guidelines (note: only the first word of header/labels should be capitalized), and is either coming verbatim from figma or has been approved by marketing (in order to get marketing approval, ask the Bug Zero team member to add the Waiting for copy label to the issue)
  • I verified proper file naming conventions were followed for any new files or renamed files. All non-platform specific files are named after what they export and are not named "index.js". All platform-specific files are named for the platform the code supports as outlined in the README.
  • I verified the JSDocs style guidelines (in STYLE.md) were followed
• If a new code pattern is added I verified it was agreed to be used by multiple Expensify engineers
• I followed the guidelines as stated in the Review Guidelines
• I tested other components that can be impacted by my changes (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar are working as expected)
• I verified all code is DRY (the PR doesn't include any logic written more than once, with the exception of tests)
• I verified any variables that can be defined as constants (ie. in CONST.ts or at the top of the file that uses the constant) are defined as such
• I verified that if a function's arguments changed that all usages have also been updated correctly
• If any new file was added I verified that:
  • The file has a description of what it does and/or why is needed at the top of the file if the code is not self explanatory
• If a new CSS style is added I verified that:
  • A similar style doesn't already exist
  • The style can't be created with an existing StyleUtils function (i.e. StyleUtils.getBackgroundAndBorderStyle(theme.componentBG))
• If new assets were added or existing ones were modified, I verified that:
  • The assets are optimized and compressed (for SVG files, run npm run compress-svg)
  • The assets load correctly across all supported platforms.
• If the PR modifies code that runs when editing or sending messages, I tested and verified there is no unexpected behavior for all supported markdown - URLs, single line code, code blocks, quotes, headings, bold, strikethrough, and italic.
• If the PR modifies a generic component, I tested and verified that those changes do not break usages of that component in the rest of the App (i.e. if a shared library or component like Avatar is modified, I verified that Avatar is working as expected in all cases)
• If the PR modifies a component related to any of the existing Storybook stories, I tested and verified all stories for that component are still working as expected.
• If the PR modifies a component or page that can be accessed by a direct deeplink, I verified that the code functions as expected when the deeplink is used - from a logged in and logged out account.
• If the PR modifies the UI (e.g. new buttons, new UI components, changing the padding/spacing/sizing, moving components, etc) or modifies the form input styles:
  • I verified that all the inputs inside a form are aligned with each other.
  • I added Design label and/or tagged @Expensify/design so the design team can review the changes.
• If a new page is added, I verified it's using the ScrollView component to make it scrollable when more elements are added to the page.
• I added unit tests for any new feature or bug fix in this PR to help automatically prevent regressions in this user flow. (N/A: no new unit tests were added; this was verified with targeted checks, CI, and platform recordings for the SAML redirect flow)
• If the main branch was merged into this PR after a review, I tested again and verified the outcome was still expected according to the Test steps.

Screenshots/Videos

Android: Native

ezyZip.42.mp4

Android: mWeb Chrome

ezyZip.40.mp4

iOS: Native

ezyZip.41.mp4

iOS: mWeb Safari

ios_mwebScreen.Recording.2026-06-13.at.5.16.54.PM.mov

MacOS: Chrome / Safari

ezyZip.39.mp4

[codecov]

Codecov Report

✅ Changes either increased or maintained existing code coverage, great job!

Files with missing lines	Coverage Δ
src/pages/signin/SignInPage.tsx	84.39% <100.00%> (+9.21%)	⬆️
src/pages/signin/SAMLSignInPage/index.native.tsx	0.00% <0.00%> (ø)
... and 12 files with indirect coverage changes

[melvin-bot]

@ZhenjaHorbach Please copy/paste the Reviewer Checklist from here into a new comment on this PR and complete it. If you have the K2 extension, you can simply click: [this button]

[github-actions]

❌ PERF-15 (docs)

This useEffect calls Navigation.isNavigationReady().then(...) which performs side effects (setHasInitiatedSAMLLogin(true), mutation of hasPendingSAMLRedirectForCurrentSignIn, and Navigation.navigate(...)) inside the .then() callback. If shouldInitiateSAMLLogin toggles rapidly or the component unmounts before the promise resolves, the stale callback will still execute, potentially navigating to the SAML sign-in page after the effect is no longer relevant.

Add a cleanup mechanism using an ignore flag to prevent stale promise resolution:

useEffect(() => {
    if (!shouldInitiateSAMLLogin) {
        return;
    }

    let ignore = false;

    Navigation.isNavigationReady().then(() => {
        if (ignore) {
            return;
        }
        setHasInitiatedSAMLLogin(true);
        hasPendingSAMLRedirectForCurrentSignIn = false;
        Navigation.navigate(ROUTES.SAML_SIGN_IN);
    });

    return () => {
        ignore = true;
    };
}, [shouldInitiateSAMLLogin]);

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[KJ21-ENG]

@ZhenjaHorbach PR is ready for review: #93528

One edge case I wanted to call out before review: the implementation follows the selected proposal by using a non-persisted pending sign-in/SAML signal keyed from ACCOUNT.isLoading && loadingForm === LOGIN_FORM, then consuming it in the redirect and cleanup guards.

During regression review, I noticed one possible multi-tab case. Since ACCOUNT and CREDENTIALS are shared through Onyx, if another visible non-leader sign-in tab is open while the initiating tab submits a required-SAML login, that other tab may also observe the shared required-SAML state and navigate to SAML. The current code preserves the existing “Another login page is opened” UI, but it does not explicitly use that flag in the required-SAML auto-redirect gate.

My take is that this is a P2 edge case and outside the core bug fix, but I wanted to ask before review: do you think we should add an explicit active/leader-tab guard for the required-SAML auto-navigation, or keep this implementation proposal-scoped and let QA validate the multi-tab behavior?