# Limitations of Grats

Grats has some known limitations. Some are innate, some have the possibility of being resolved with effort. In the interest of transparency, I wanted to document them here.

## Method wrappers

Sometimes it can be useful to wrap a method in a function. This can emulate the behavior of of a decorator. For example:

```typescript
class User {
  approve_post = requireAuthed(({ id }: { id: ID }) => {
    Post.approve(id);
    return true;
  });
}
```

Currently Grats cannot handle this because it's not able to "see" what type the wrapper function will return, or what arguments the returned function will accept.

## Inferred types

In theory Grats could ask TypeScript what type it's inferring for a given location. For example, in the following function, TypeScript would _infer_ that it returns `string`, so we shouldn't need to explicitly annotate the return type.

```typescript
/** @gqlField */
export function name(_: User) {
  return "John";
}
```

However, this ends up not being a good fit for GraphQL's type system, since GraphQL is "nominal" rather than "structural" like TypeScript. See [Structural vs Nominal Typing](./structural-vs-nominal-typing.md) for more details.

## Descriptions and @deprecated on TypeScript union @gqlEnums

Currently Grats does not support descriptions or `@deprecated` on GraphQL enum values when the enum is defined as a TypeScript union.

```typescript
/** @gqlEnum */
type MyEnum =
  /** This gets ignored */
  | "A"
  /** So does this */
  | "B";
```

This is because we rely on the TypeScript compiler to tell us which docblocks are "attached" to a given AST node, and TypeScript doesn't see those comments as attached to anything. In the future we could explore implementing our own comment attachment, but it is a difficult problem.

## Alternate comment types

It would be nice if Grats supported other comment types, such as regular block comments (with one *) or inline comments (starting with two slashes). However we can't currently.

This is because we rely on the TypeScript compiler to tell us which docblocks are "attached" to a given AST node, and TypeScript doesn't see those comments as attached to anything. In the future we could explore implementing our own comment attachment, but it is a difficult problem.