[discussion]: Automatically transforms enums to CAPITALIZED_WITH_UNDERSCORES style

[kasvith]

Is there an existing issue that is already proposing this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe it

In GraphQL world, enums are represented as CAPITALIZED_WITH_UNDERSCORES. This is described in the GraphQL spec as well.

GraphQL

enum CatStatus {
    HAPPY_AND_HEALTHY
    SAD_AND_HEALTHY
}

In the typescript world, it's common to use PascalCase for enum representations.

Typescript

enum CatStatus {
   HappyAndHealthy,
   SadAndHealthy
}

Code-First approach in the docs suggests using CAPITALIZED_WITH_UNDERSCORES as enum values. But that doesn't play nice with Typescript world.

Describe the solution you'd like

Automatically transform AnyCase, anyCase , any_case to the respective GraphQL enum representation on code generation and map to correct internal representation in NestJS side.

So,

Typescript

enum CatStatus {
   happy_AndHealthy,
   SadAndHealthy
}

Will become

GraphQL

enum CatStatus {
    HAPPY_AND_HEALTHY
    SAD_AND_HEALTHY
}

in GraphQL

This will allow us to follow best practices in both worlds.

For example, Elixir Absinthe follows this pattern

Teachability, documentation, adoption, migration strategy

This can be a breaking change, so it can be added as an optional argument to registerEnumType

What is the motivation / use case for changing the behavior?

Enforcing best practices in both GraphQL and Typescript

[kasvith]

I will start working on this

[kasvith]

So the idea is as follows

Since we do the mapping to internal value representation anyways, it makes no difference representing them in different ways in the schema.

enum Directions{
    Up = 'up',
    Down = 'down',
    Left = 'left',
    Right = 'right'
}

enum DirectionsCapitalized{
    UP = 'up',
    DOWN = 'down',
    LEFT = 'left',
    RIGHT = 'right'
}

console.log('up' === Directions.Up) // true
console.log('up' === DirectionsCapitalized.UP) // true

we can safely map any Enum representation into the correct case respected in graphql world, and use the appropriate value in Typescript world

[kasvith]

If we enforce this automatically, it would break only client-side implementations as server-side would remain the same

[kamilmysliwiec]

Let's track this here #1852