allow usage of symbol instead of string

[thomaschaaf]

No description provided.

[marcjulian]

Thanks for the PR, what is your use case for this? Please provide an example

[NedcloarBR]

I think this is a valuable improvement. Since @Inject already supports Symbol as an injection token, allowing it here would make the library more flexible and consistent with Nest’s capabilities.

Using Symbol can also help avoid naming conflicts and makes dependency tokens safer in larger or more modular applications. Supporting it would improve developer experience without introducing breaking changes.

[NedcloarBR]

@thomaschaaf I think simply changing the type to string | symbol might not be the best approach here.

In Nest itself, the @Inject decorator does not limit the token to string | symbol. The implementation shows a more flexible typing strategy:

• https://github.com/nestjs/nest/blob/master/packages/common/decorators/core/inject.decorator.ts#L6
• https://github.com/nestjs/nest/blob/master/packages/common/decorators/core/inject.decorator.ts#L39

Aligning with Nest’s implementation would likely make this change more robust and future-proof, instead of just widening the type to a union.