Many Typescript types are only accessible by accessing internal files

[electrovir]

There are lots of internal types that say "export type" but there's not any way to actually access them from a TypeScript import.

Example:

I'm trying to use the internal ColorTypes type (input to the new Color() constructor). These are the ways I've tried so far that don't work:

1. default import:

   import Color from 'colorjs.io';
   type ColorTypes = Color.ColorTypes; // does not exist

2. destructured import:

   import {ColorTypes} from 'colorjs.io'; // does not exist

Workaround

With some type system trickery it is possible to extract this type, but it's quite annoying and requires the use of a huge OverloadParameters helper from this comment:

import Color from 'colorjs.io';

/** Overloaded function type helpers */
type OverloadProps<TOverload> = Pick<TOverload, keyof TOverload>;

type OverloadUnionRecursive<TOverload, TPartialOverload = unknown> = TOverload extends (
    ...args: infer TArgs
) => infer TReturn
    ? TPartialOverload extends TOverload
        ? never
        :
              | OverloadUnionRecursive<
                    TPartialOverload & TOverload,
                    TPartialOverload & ((...args: TArgs) => TReturn) & OverloadProps<TOverload>
                >
              | ((...args: TArgs) => TReturn)
    : never;

type OverloadUnion<TOverload extends (...args: any[]) => any> = Exclude<
    OverloadUnionRecursive<(() => never) & TOverload>,
    TOverload extends () => never ? never : () => never
>;

type OverloadParameters<T extends (...args: any[]) => any> = Parameters<OverloadUnion<T>>;

/** Extracted ColorTypes */
type ColorTypes = Extract<OverloadParameters<(typeof Color)['get']>, [any]>[0];

[electrovir]

Other import attempts that fail:

1. import {ColorTypes} from 'colorjs.io/dist/color';
2. import {ColorTypes} from 'colorjs.io/src/color';

[electrovir]

Ah, I found one that works:

import {ColorTypes} from 'colorjs.io/types/src/color';

At least there's a sane way to access them. Still, this seems like an accidental feature; I'd expect to be able to access the types directly from a colorjs.io import.

[MysteryBlokHed]

When I was writing the types I guess I didn't think about re-exporting them at the top level. I could make a PR for that when I get a chance, probably today or tomorrow.

[jgerigmeyer]

Ah, I found one that works:

import {ColorTypes} from 'colorjs.io/types/src/color';

At least there's a sane way to access them. Still, this seems like an accidental feature; I'd expect to be able to access the types directly from a colorjs.io import.

Yeah, I agree. I've been accessing them this same way (e.g. import type { PlainColorObject } from 'colorjs.io/types/src/color';), but it makes sense to export them at the top level. @MysteryBlokHed I'm happy to review your PR once it's submitted.