The getter 'length' isn't defined for the type 'List<Meals> Function({bool growable})'
Solution 1:
Change toList to toList().
final categoryMeals = DUMMY_MEALS.where((meal) {
return meal.categories.contains(categoryId);
}).toList;
Change toList to toList().
final categoryMeals = DUMMY_MEALS.where((meal) {
return meal.categories.contains(categoryId);
}).toList;