flutter_shopping/example/lib/src/utils/go_router.dart

import "package:flutter/material.dart";
import "package:go_router/go_router.dart";

CustomTransitionPage buildScreenWithFadeTransition<T>({
  required BuildContext context,
  required GoRouterState state,
  required Widget child,
}) =>
    CustomTransitionPage<T>(
      key: state.pageKey,
      child: child,
      transitionsBuilder: (context, animation, secondaryAnimation, child) =>
          FadeTransition(opacity: animation, child: child),
    );

CustomTransitionPage buildScreenWithoutTransition<T>({
  required BuildContext context,
  required GoRouterState state,
  required Widget child,
}) =>
    CustomTransitionPage<T>(
      key: state.pageKey,
      child: child,
      transitionsBuilder: (context, animation, secondaryAnimation, child) =>
          child,
    );