Swagger Utils to generate Schema Id

SwashBuckleUtils.cs

static class SwashBuckleUtils
{
    private static readonly Dictionary<Type, string> _map = new Dictionary<Type, string>();

    private static string ToSchemaId(Type type, bool skipDeclaringType)
    {
        if (!_map.TryGetValue(type, out var name))
        {
            if (type.IsGenericType && !type.IsGenericTypeDefinition)
            {
                var genericTypeName = type.GetGenericTypeDefinition().Name;
                // Check if it's a real generic type. Non-generic types nested in generic types will also have IsGenericType() == true but won't have a '`' in their name
                // "Real" generic type names must be trimmed to exclude everything after '`' including that character.
                int p = genericTypeName.IndexOf('`');
                if (p > 0)
                    genericTypeName = genericTypeName[..p];
                name = $"{genericTypeName}Of{string.Join("And", type.GetGenericArguments().Select(t => ToSchemaId(t, skipDeclaringType: true)))}";
            }
            else
            {
                // the .Replace() handles the case of nested types, since '+' is not a valid schema id character
                name = type.Namespace + '.' + type.Name.Replace('+', '_');
                if (type.DeclaringType is not null && !skipDeclaringType)
                    name = ToSchemaId(type.DeclaringType) + '_' + name;
            }
            _map[type] = name;
        }
        return name;
    }

    public static string ToSchemaId(Type type)
    {
        var name = ToSchemaId(type, skipDeclaringType: false);
        return name;
    }

    public static IEnumerable<Type> AnnotationsKnownTypesSelector(Type type)
    {
        var subtypes = new List<Type>();

        foreach (var knownTypeAttribute in type.GetCustomAttributes(false).OfType<KnownTypeAttribute>())
        {
            if (knownTypeAttribute.Type is not null)
                subtypes.Add(knownTypeAttribute.Type);
            else if (knownTypeAttribute.MethodName is not null)
                throw new InvalidOperationException($"{type}: KnownType(\"{knownTypeAttribute.MethodName}\") is not supported");
        }

        return subtypes;
    }
}