Nav Bridge

A progressive, router-agnostic navigation layer for Flutter that allows you to wrap existing GoRouter apps and migrate to a clean, testable, decoupled architecture — without rewriting your routes.

Why Nav Bridge?

Flutter apps are usually tightly coupled to a routing library:

// ❌ Your business logic depends on GoRouter
context.go('/users/42');
context.push('/settings');

This creates several problems:

• Vendor lock-in: Business logic depends on GoRouter/AutoRoute
• Untestable: Navigation requires Flutter widgets
• Expensive migrations: Changing routers means rewriting navigation
• Tight coupling: UI and routing are inseparable

Nav Bridge solves this with a thin abstraction layer:

// ✅ Your app talks to AppRouter, not GoRouter
appRouter.goToUserProfile('42');

Key Features

Feature	Description
Wrap Mode	Use your existing GoRouter without any changes
Progressive Migration	Migrate one feature at a time, old & new coexist
Full DI Support	Riverpod Ref available in all guards
Guard Bridges	Keep existing guards working immediately
InMemoryAdapter	Unit test navigation without Flutter
Shell Navigation	Full StatefulShellRoute support

Installation

dependencies:
  nav_bridge: ^2.0.0
  go_router: ^15.0.0

  # Optional - for Riverpod guards
  flutter_riverpod: ^2.4.0

flutter pub get

Quick Start

Step 1: Wrap Your Existing Router

Zero changes to your existing code:

import 'package:nav_bridge/nav_bridge.dart';

// Your existing GoRouter (unchanged)
final goRouter = GoRouter(
  routes: [...],
  redirect: myRedirectLogic,
);

// Wrap it with Nav Bridge
final adapter = GoRouterAdapter.wrap(goRouter);

// Everything still works!
context.go('/profile/42');  // ✅ Still works

Step 2: Add Guards with DI Support

final adapter = GoRouterAdapter.wrap(
  goRouter,
  additionalGuards: [AuthGuard(), RoleGuard()],
);

// Inject dependencies (Riverpod Ref, etc.)
adapter.contextBuilder = (state) => {
  'ref': ref,
  'goRouterState': state,
  'context': navigatorKey.currentContext,
};

Step 3: Create Type-Safe Navigation (Optional)

abstract class AppRouter {
  Future<void> goToHome();
  Future<void> goToUserProfile(String userId);
}

class MyAppRouter implements AppRouter {
  final GoRouterAdapter _adapter;

  MyAppRouter(this._adapter);

  @override
  Future<void> goToUserProfile(String userId) =>
      _adapter.go('/profile/$userId');
}

Guards

Modern Riverpod Guards

class AuthGuard extends RiverpodRouteGuard {
  @override
  int get priority => 100;  // Higher = runs first

  @override
  List<String>? get excludes => ['/login', '/register'];

  @override
  Future<GuardResult> canActivateWithRef(
    GuardContext context,
    Ref ref,
  ) async {
    final isAuthenticated = ref.read(authProvider).isAuthenticated;

    if (!isAuthenticated) {
      return GuardResult.redirect('/login');
    }

    return GuardResult.allow();
  }
}

Bridge Existing Guards (Zero Rewrite)

Already have guards? Bridge them without any changes:

// Your existing guard function
FutureOr<GuardResult> myExistingGuard(
  BuildContext context,
  GoRouterState state,
  Ref ref,
) async {
  // Your existing logic...
}

// Bridge it - zero changes needed!
final bridgedGuard = GoRouterGuardBridge(myExistingGuard);

Guard Result Types

sealed class GuardResult {
  // Allow navigation
  static GuardAllow allow();

  // Redirect to another path
  static GuardRedirect redirect(String path, {Map<String, dynamic>? extra});

  // Block navigation
  static GuardReject reject({String? reason});
}

Unit Testing

Test navigation without Flutter widgets:

void main() {
  group('Navigation', () {
    test('authenticated user can access profile', () async {
      final router = InMemoryAdapter(
        guards: [MockAuthGuard(isAuthenticated: true)],
      );

      await router.go('/profile/42');

      expect(router.currentLocation, '/profile/42');
    });

    test('unauthenticated user is redirected to login', () async {
      final router = InMemoryAdapter(
        guards: [MockAuthGuard(isAuthenticated: false)],
      );

      await router.go('/profile/42');

      expect(router.currentLocation, '/login');
    });

    test('tracks navigation history', () async {
      final router = InMemoryAdapter();

      await router.go('/');
      await router.push('/profile/42');
      await router.push('/settings');

      expect(router.navigationHistory, ['/', '/profile/42', '/settings']);

      router.pop();
      expect(router.currentLocation, '/profile/42');
    });
  });
}

Progressive Migration Guide

Phase 1: Wrap (Day 1)

// Just wrap, nothing else changes
final adapter = GoRouterAdapter.wrap(existingRouter);

Phase 2: Bridge Guards (Week 1)

// Bridge existing guards
final bridged = GoRouterGuardBridge(existingGuard);

Phase 3: Add AppRouter (Week 2)

// Create type-safe navigation
abstract class AppRouter {
  Future<void> goToProfile(String id);
}

Phase 4: Migrate Features (Ongoing)

// Old and new coexist
context.go('/old');           // Old code ✅
appRouter.goToProfile('42');  // New code ✅

Architecture

┌─────────────────────────────────────────────────────────┐
│                    Feature Code                          │
│              (Uses AppRouter interface)                  │
└─────────────────────────┬───────────────────────────────┘
                          │
                          ▼
┌─────────────────────────────────────────────────────────┐
│                     AppRouter                            │
│            (Your type-safe abstraction)                  │
└─────────────────────────┬───────────────────────────────┘
                          │
                          ▼
┌─────────────────────────────────────────────────────────┐
│                     Nav Bridge                           │
│         (Guards, DI, Navigation abstraction)             │
└─────────────────────────┬───────────────────────────────┘
                          │
                          ▼
┌─────────────────────────────────────────────────────────┐
│              GoRouterAdapter.wrap()                      │
│            (Wraps your existing router)                  │
└─────────────────────────┬───────────────────────────────┘
                          │
                          ▼
┌─────────────────────────────────────────────────────────┐
│              Your Existing GoRouter                      │
│          (Routes, Shell, everything intact)              │
└─────────────────────────────────────────────────────────┘

API Reference

Adapters

Adapter	Use Case
GoRouterAdapter.wrap()	Existing GoRouter apps (recommended)
GoRouterAdapter.create()	New applications
GoRouterAdapter.withGuards()	New with integrated guard system
InMemoryAdapter	Unit testing

Guards

Class	Description
RouteGuard	Base class for all guards
RiverpodRouteGuard	Guard with Riverpod Ref access
GoRouterGuardBridge	Bridge for existing guards with Ref
SimpleGoRouterGuardBridge	Bridge for guards without Ref
GoRouterRedirectBridge	Bridge for redirect functions
CompositeGuard	Combine guards with AND logic
AnyGuard	Combine guards with OR logic

Core Classes

Class	Description
GuardContext	Context passed to guards with DI support
GuardResult	Sealed class: Allow, Redirect, Reject
RouteDefinition	Router-agnostic route definition
ShellRouteDefinition	Shell/tab navigation support

Roadmap

• GoRouter wrap mode
• Riverpod guard support
• Guard bridge adapters
• InMemoryAdapter for testing
• Shell navigation support
• AutoRoute adapter
• Beamer adapter
• Typed route code generation
• Analytics observers
• Transition abstraction

When Should You Use This?

Scenario	Recommendation
Existing GoRouter app	Perfect fit
Large team / enterprise	Highly recommended
Need navigation unit tests	Essential
Planning router migration	Future-proof
Small personal app	Optional

Community

• Report bugs
• Request features
• Read the docs
• Discussions

Contributing

Contributions are welcome! Please read our Contributing Guide first.

# Clone the repo
git clone https://github.com/chekarhamza88-stack/nav_bridge.git

# Install dependencies
flutter pub get

# Run tests
flutter test

# Check analysis
flutter analyze

License

MIT License - see LICENSE for details.

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Nav Bridge doesn't replace GoRouter.
It makes GoRouter testable, replaceable, decoupled, and enterprise-ready.

Made with love by chekarhamza88-stack