public TypeTracker(ISchema schema)
{
EnterOperationDefinition = node =>
{
var root = node.Operation switch
{
OperationType.Query => schema.Query,
OperationType.Mutation => schema.Mutation,
OperationType.Subscription => schema.Subscription,
_ => throw new ArgumentOutOfRangeException()
};
Types.Push(root);
};
LeaveOperationDefinition = node => { Types.TryPop(out _); };
EnterSelectionSet = node => { ParentTypes.Push(CurrentType); };
LeaveSelectionSet = node => { ParentTypes.TryPop(out _); };
EnterFieldSelection = node =>
{
if (ParentType is not null)
{
var fieldDefinition = schema.GetField(ParentType.Name, node.Name);
FieldDefinitions.Push(fieldDefinition ?? null);
if (fieldDefinition?.Type is not null)
{
var fieldTypeDefinition = Ast.UnwrapAndResolveType(schema, fieldDefinition.Type);
if (fieldTypeDefinition is not null && TypeIs.IsOutputType(fieldTypeDefinition))
{
Types.Push(fieldTypeDefinition);
}
else
{
Types.Push(null);
}
}
else
{
Types.Push(null);
}
}