[Typescript] - Constrained identity function

cif.ts

/**
 * Problem: defining object with interfaces grant autocomplete but also widen all types (e.g. `true`  becomes `boolean`)
 * Defining object with `as const` infers all the narrowed types but looses autocomplete 

 * Solution: Create utility function with constrained generic type parameters. More info [here](https://kentcdodds.com/blog/how-to-write-a-constrained-identity-function-in-typescript)
 */

interface ISchema {
  id: string;
  description: string;
  bool: boolean;
}

const createSchema = <T extends ISchema>(schema: Readonly<T>) => schema;

const schema = createSchema({
  id: "qwer",
  description: "description",
  bool: true,
});

schema.id // 'qwer'
schema.bool // true