db model types

[jmaldon1]

I am not seeing a clear answer anywhere so I thought I'd just ask.

How do you add types for a model in typescript.

For example:

export const db = factory({
  muscle: {
    id: primaryKey(Number),
    muscle: String,
  }
});

What should the type of this muscle array be?

const muscles = [];

Do I need to create my own type:

export type muscle = {
  id: number;
  muscle: string;
};

and then do this:

const muscles: muscle[] = []

[kettanaito]

Hey, @jmaldon1.

The types are inferred from the value getter you give to your model. This is done automatically by the library, and the result you get is already typed according to your model:

const db = factory({
  muscle: {
    id: primaryKey(String),
    muscle: string
  }
})

const muscles = db.muscle.findMany()
// Array<{ id: string, muscle: string }>

If you wish to extract the type from the generated db client, you can do that from the db[model].findFirst return type:

type ExtractModelType<F extends Function> = ReturnType<F>

type Muscle = ExtractModelType<typeof db.muscle.findFirst>
// { id: strig, muscle: string }

I wouldn't advise doing this though.

The library does not support accepting types as a generic to the factory just yet. You can follow and contribute to this in #36.

[jmaldon1]

So this is the usecase that I am having issues with:

const muscles = [];

for (let i = 0; i < 10; i++) {
  const id = i + 1;

  muscles.push(db.muscle.create(createMuscleData(id)));
}

for (let i = 0; i < 10; i++) {
  const randomMuscles = [];  // Error: Variable 'randomMuscles' implicitly has type 'any[]' in some locations where its type cannot be determined.
  for (let i = 0; i < 3; i++) {
    const randomMuscle = muscles[Math.floor(Math.random() * muscles.length)];
    if (randomMuscles.includes(randomMuscle)) {  // Error: Variable 'randomMuscles' implicitly has an 'any[]' type.
      i--;
      continue;
    }
    randomMuscles.push(randomMuscle);
  }
}

It seems like I need to provide a type to randomMuscles before doing .includes

[kettanaito]

Okay, in this case you have to describe the data by yourself:

interface Muscle {
  id: string
  muscle: string
}

const muscles: Muscle[] = []

This is not strictly a library-related question.