fix(react-router): cleaning up tab navigation to use proper navigation step post debugging

packages/react-router/src/ReactRouter/IonRouter.tsx

@@ -114,6 +114,18 @@ export const IonRouter = ({ children, registerHistoryListener }: PropsWithChildr
     // for future navigations once React has committed the mount. This avoids
     // duplicate entries when React StrictMode runs an extra render pre-commit.
     locationHistory.current.add(routeInfo);
+
+    // If IonTabBar already called handleSetCurrentTab during render (before this
+    // effect), the tab was stored in currentTab.current but the history entry was
+    // not yet seeded. Apply the pending tab to the seed entry now.
+    if (currentTab.current) {
+      const ri = { ...locationHistory.current.current() };
+      if (ri.tab !== currentTab.current) {
+        ri.tab = currentTab.current;
+        locationHistory.current.update(ri);
+      }
+    }
+
     registerHistoryListener(handleHistoryChange);
 
     didMountRef.current = true;
@@ -179,14 +191,17 @@ export const IonRouter = ({ children, registerHistoryListener }: PropsWithChildr
     const leavingUrl = leavingLocationInfo.pathname + leavingLocationInfo.search;
     if (leavingUrl !== location.pathname + location.search) {
       if (!incomingRouteParams.current) {
-        // Determine if the destination is a tab route by checking if it matches
-        // the pattern of tab routes (containing /tabs/ in the path)
-        const isTabRoute = /\/tabs(\/|$)/.test(location.pathname);
-        const tabToUse = isTabRoute ? currentTab.current : undefined;
-
-        // If we're leaving tabs entirely, clear the current tab
-        if (!isTabRoute && currentTab.current) {
-          currentTab.current = undefined;
+        // Use history-based tab detection instead of URL-pattern heuristics,
+        // so tab routes work with any URL structure (not just paths containing "/tabs").
+        // Fall back to currentTab.current only when the destination is within the
+        // current tab's path hierarchy (prevents non-tab routes from inheriting a tab).
+        let tabToUse = locationHistory.current.findTabForPathname(location.pathname);
+        if (!tabToUse && currentTab.current) {
+          const tabFirstRoute = locationHistory.current.getFirstRouteInfoForTab(currentTab.current);
+          const tabRootPath = tabFirstRoute?.pathname;
+          if (tabRootPath && (location.pathname === tabRootPath || location.pathname.startsWith(tabRootPath + '/'))) {
+            tabToUse = currentTab.current;
+          }
         }
 
         /**
@@ -256,7 +271,7 @@ export const IonRouter = ({ children, registerHistoryListener }: PropsWithChildr
       let routeInfo: RouteInfo;
 
       // If we're navigating away from tabs to a non-tab route, clear the current tab
-      if (!/\/tabs(\/|$)/.test(location.pathname) && currentTab.current) {
+      if (!locationHistory.current.findTabForPathname(location.pathname) && currentTab.current) {
         currentTab.current = undefined;
       }
 
@@ -441,7 +456,13 @@ export const IonRouter = ({ children, registerHistoryListener }: PropsWithChildr
    */
   const handleSetCurrentTab = (tab: string) => {
     currentTab.current = tab;
-    const ri = { ...locationHistory.current.current() };
+    const current = locationHistory.current.current();
+    if (!current) {
+      // locationHistory not yet seeded (e.g., called during initial render
+      // before mount effect). The mount effect will seed the correct entry.
+      return;
+    }
+    const ri = { ...current };
     if (ri.tab !== tab) {
       ri.tab = tab;
       locationHistory.current.update(ri);
@@ -553,26 +574,27 @@ export const IonRouter = ({ children, registerHistoryListener }: PropsWithChildr
     let navigationTab = tab;
 
     // If no explicit tab is provided and we're in a tab context,
-    // check if the destination path is outside of the current tab context
+    // check if the destination path is outside of the current tab context.
+    // Uses history-based tab detection instead of URL pattern matching,
+    // so it works with any tab URL structure.
     if (!tab && currentTab.current && path) {
-      // Get the current route info to understand where we are
-      const currentRoute = locationHistory.current.current();
-
-      // If we're navigating from a tab route to a completely different path structure,
-      // we should clear the tab context. This is a simplified check that assumes
-      // tab routes share a common parent path.
-      if (currentRoute && currentRoute.pathname) {
-        // Extract the base tab path (e.g., /routing/tabs from /routing/tabs/home)
-        const tabBaseMatch = currentRoute.pathname.match(/^(.*\/tabs)/);
-        if (tabBaseMatch) {
-          const tabBasePath = tabBaseMatch[1];
-          // If the new path doesn't start with the tab base path, we're leaving tabs
-          if (!path.startsWith(tabBasePath)) {
+      // Check if destination was previously visited in a tab context
+      const destinationTab = locationHistory.current.findTabForPathname(path);
+      if (destinationTab) {
+        // Previously visited as a tab route - use the known tab
+        navigationTab = destinationTab;
+      } else {
+        // New destination - check if it's a child of the current tab's root path
+        const tabFirstRoute = locationHistory.current.getFirstRouteInfoForTab(currentTab.current);
+        if (tabFirstRoute) {
+          const tabRootPath = tabFirstRoute.pathname;
+          if (path === tabRootPath || path.startsWith(tabRootPath + '/')) {
+            // Still within the current tab's path hierarchy
+            navigationTab = currentTab.current;
+          } else {
+            // Destination is outside the current tab context
             currentTab.current = undefined;
             navigationTab = undefined;
-          } else {
-            // Still within tabs, preserve the tab context
-            navigationTab = currentTab.current;
           }
         }
       }

packages/react-router/test/base/tests/e2e/specs/tab-history-isolation.cy.js

@@ -121,4 +121,84 @@ describe('Tab History Isolation', () => {
     cy.ionPageVisible('tab-a');
     cy.url().should('include', '/tab-history-isolation/a');
   });
+
+  /**
+   * Browser back/forward tests for non-"/tabs/" URL paths.
+   *
+   * These tests verify that per-tab history isolation works correctly
+   * when using browser back/forward buttons (POP events) with tab routes
+   * that do NOT contain "/tabs/" in their URL path.
+   *
+   * The tab-history-isolation routes use paths like /tab-history-isolation/a,
+   * /tab-history-isolation/b, etc. — no "/tabs/" segment. This exercises
+   * the context-driven tab detection (via location history) rather than
+   * URL-pattern-based detection.
+   */
+  it('should preserve tab context through browser back from detail page within a tab', () => {
+    cy.visit(`http://localhost:${port}/tab-history-isolation/a`);
+    cy.ionPageVisible('tab-a');
+
+    // Navigate to details within Tab A
+    cy.get('#go-to-a-details').click();
+    cy.ionPageHidden('tab-a');
+    cy.ionPageVisible('tab-a-details');
+
+    // Use browser back - should go back within the same tab
+    cy.go('back');
+    cy.ionPageVisible('tab-a');
+    cy.url().should('include', '/tab-history-isolation/a');
+    cy.url().should('not.include', '/details');
+  });
+
+  it('should handle browser forward after browser back within a tab', () => {
+    cy.visit(`http://localhost:${port}/tab-history-isolation/a`);
+    cy.ionPageVisible('tab-a');
+
+    // Navigate to details within Tab A
+    cy.get('#go-to-a-details').click();
+    cy.ionPageHidden('tab-a');
+    cy.ionPageVisible('tab-a-details');
+
+    // Browser back
+    cy.go('back');
+    cy.ionPageVisible('tab-a');
+    cy.url().should('not.include', '/details');
+
+    // Browser forward - should return to details
+    cy.go('forward');
+    cy.ionPageVisible('tab-a-details');
+    cy.url().should('include', '/tab-history-isolation/a/details');
+  });
+
+  it('should preserve per-tab history when using browser back after navigating within a tab and switching tabs', () => {
+    cy.visit(`http://localhost:${port}/tab-history-isolation/a`);
+    cy.ionPageVisible('tab-a');
+
+    // Navigate to details within Tab A
+    cy.get('#go-to-a-details').click();
+    cy.ionPageHidden('tab-a');
+    cy.ionPageVisible('tab-a-details');
+
+    // Switch to Tab B via tab bar
+    cy.ionTabClick('Tab B');
+    cy.ionPageHidden('tab-a-details');
+    cy.ionPageVisible('tab-b');
+
+    // Navigate to details within Tab B
+    cy.get('#go-to-b-details').click();
+    cy.ionPageHidden('tab-b');
+    cy.ionPageVisible('tab-b-details');
+
+    // Use browser back from Tab B details - should go back to Tab B root
+    cy.go('back');
+    cy.ionPageVisible('tab-b');
+    cy.url().should('include', '/tab-history-isolation/b');
+    cy.url().should('not.include', '/details');
+
+    // Switch back to Tab A - should still show Tab A details (preserved)
+    cy.ionTabClick('Tab A');
+    cy.ionPageHidden('tab-b');
+    cy.ionPageVisible('tab-a-details');
+    cy.url().should('include', '/tab-history-isolation/a/details');
+  });
 });

packages/react/src/routing/LocationHistory.ts

@@ -175,4 +175,16 @@ export class LocationHistory {
   canGoBack() {
     return this.locationHistory.length > 1;
   }
+
+  findTabForPathname(pathname: string): string | undefined {
+    for (const tab of Object.keys(this.tabHistory)) {
+      const routeInfos = this.tabHistory[tab];
+      for (let i = routeInfos.length - 1; i >= 0; i--) {
+        if (routeInfos[i].pathname === pathname) {
+          return tab;
+        }
+      }
+    }
+    return undefined;
+  }
 }