Explicit types

[mrdziuban]

For a given case class:

case class Foo(int: Int, str: String)

Old generated code

import * as t from "io-ts";

export const fooC = t.type({
  int: t.number,
  str: t.string
});
export type FooC = typeof fooC;
export type Foo = t.TypeOf<FooC>;

New generated code

Comments are included for explanation

import * as t from "io-ts";

// The codec type is generated explicitly and does not refer to the codec value
export type FooC = t.TypeC<{
  int: t.NumberC,
  str: t.StringC
}>;
// The value type is generated explicitly and does not refer to the codec type or value
export type Foo = {
  int: number,
  str: string
};
// The codec value is annotated with the codec type
export const fooC: FooC = t.type({
  int: t.number,
  str: t.string
// The codec value is proven to satisfy `t.Type<ValueType, unknown>`
// This isn't strictly necessary but is nice to verify that the generation of types/values aligns
}) satisfies t.Type<Foo, unknown>;