CHANGELOG.md

exhaustive

1.1.2

Patch Changes

• aec6f75 Thanks @lukemorales! - Improve inference of return types with new generic value

  The return type of exhaustive and exhaustive.tag will now be inferred based on the return type of the callback function.

  type Union = "IDLE" | "LOADING" | "SUCCESS" | "ERROR";
  
  type HumanReadableUnion = "idle" | "loading" | "success" | "error";
  
  function unionToHumanReadableString(union: Union): HumanReadableUnion {
    return exhaustive(union, {
      IDLE: () => "idle",
      LOADING: () => "loading",
      SUCCESS: () => "success",
      ERROR: (value) => value.toLowerCase(), // type `string` is not assignable to type `HumanReadableUnion`
    });
  }

1.1.1

Patch Changes

• d210075 Thanks @lukemorales! - Fix exhaustive compile checks

  With the added support of exhaustive boolean checks, TypeScript stopped complaining if a key was missing in the exhaustive object due to how the new types were declared. The types were adjusted to bring back the expected behavior of TypesScript complaining at compile-time if you forget to handle all the use-cases.

1.1.0

Minor Changes

• #6 abc000e Thanks @lukemorales! - ## Add support for booleans

  Both exhaustive and exhaustive.tag can now be exhaustive checked against booleans:

  function handleStatus(isSelected: boolean) {
    return exhaustive(isSelected, {
      true: () => {
        // ...run handler for true case
      },
      false: () => {
        // ...run handler for false case
      },
    });
  }

  type ProfileStatus =
    | { checked: true; data: string }
    | { checked: false; error: string };
  
  function handleProfileStatus(status: ProfileStatus) {
    return exhaustive.tag(status, "checked", {
      true: (value) => saveProfile(value.data),
      //           ^? value is { checked: true; data: string }
      false: (value) => throwException(value.error),
      //           ^? value is { checked: false; error: string }
    });
  }

1.0.0

Major Changes

• #4 b287bbb Thanks @lukemorales! - ## Exposed Exhaustive types and added new generic slot in core function for type of output

  The types ExhaustiveUnion and Exhaustiveag are now exposed for your own convenience if you'd like to override the generic slots of exhaustive. The inferred output was also added as a new slot in the function generics, allowing you to also override the output value of exhaustive:

  import { exhaustive, type ExhaustiveTag } from "exhaustive";
  
  exhaustive<
    RequestState,
    "state",
    ExhaustiveTag<RequestState, "state">,
    JSX.Element
  >(request, "state", {
    IDLE: () => null,
    LOADING: (value) => <Loading />,
    SUCCESS: (value) => <List data={value.data} />,
    ERROR: (value) => <Error message={value.error} />,
  });

  BREAKING CHANGES

  Renamed _tag method to tag

  The _tag method was exposed as a some sort of secondary method to enhance the experience with Tagged Unions. Since the DX of using it is vastly superior compared to the Tagged Union overload in exhaustive, and it seems that we cannot improve the overload inference on the core funcion, the underscore has been removed from the method name and now you should used it as exhaustive.tag to make it official as the preferred way to exhaustive check Tagged Unions:

  const area = (s: Shape) => {
  - return exhaustive._tag(s, 'kind', {
  + return exhaustive.tag(s, 'kind', {
      square: (shape) => shape.size ** 2,
      rectangle: (shape) => shape.width * shape.height,
      circle: (shape) => Math.PI * shape.radius ** 2,
    });
  };

Minor Changes

• #4 b287bbb Thanks @lukemorales! - ## Add exhaustive.tag overload to core function

  The same functionality of exhaustive.tag is available in the main function by adding a third argument to exhaustive that will trigger the Tagged Union overload.

  const area = (s: Shape) => {
    return exhaustive(s, "kind", {
      square: (shape) => shape.size ** 2,
      rectangle: (shape) => shape.width * shape.height,
      circle: (shape) => Math.PI * shape.radius ** 2,
    });
  };

  PS: Note that TypeScript has a limitation inferring the Tagged Union overload via argument types because they are generic values. Typescript will only fallback to the Tagged Union overload when you add a third argument. This means autocomplete for the Tagged Union keys will not exist until you declare an empty object as the third argument:

  exhaustive(shape, "kind", {});
  //                        ^ this will trigger the Tagged Union overload

  This feature is being added as a reflect of how the API was originally intended. Use it at your own convenience, but if you prefer the better DX of inferred types from the start, calling exhaustive.tag is still preferrable.

0.1.0

Minor Changes

• #2 c1c4c65 Thanks @lukemorales! - Initial release of exhaustive and corrupt functions