[@types/prop-types] Add support of as const to oneOf

[ibezkrovnyi]

Common way before microsoft/TypeScript#29510 was to use tuple trick

export const tuple = <T extends string[]>(...args: T) => args;
const sizes = tuple('default', 'large');
export type SizeType = typeof sizes[number];

export const Button = (props: { size: SizeType }) => <div></div>;

Button.propTypes = {
  size: PropTypes.oneOf(sizes),
};

After microsoft/TypeScript#29510 has landed we could use as const

const sizes = ['default', 'large'] as const;
export type SizeType = typeof sizes[number];

export const Button = (props: { size: SizeType }) => <div></div>;

Button.propTypes = {
  size: PropTypes.oneOf(sizes),   // Error: Type 'readonly ["default", "large"]' is missing the following properties from type '{}[]': pop, push, reverse, shift and 6 more. [2345]
};

Some evidence

tuple is pretty common approach, for example, it is used in ant.design

Change

Change is to replace type T[] of oneOf parameter with ReadonlyArray<T>.
This change relaxes requirement for an Array.

Also I tried readonly T[] and it works fine too. But this is pretty new feature

Tested

This change was tested on my project and I used as const in part of code location, while keeping old way for another part of code locations. Both old and new ways work fine.

[ibezkrovnyi]

Build Failed.
Some issue with typescript@3.5.0-dev20190412 (next) and recompose/recompose-test.tsx
Reverting my changes didn't help. It is probably some change introduced by new version of TypeScript compiler. After moving to TypeScript@3.4.3 issues has gone.

[typescript-bot]

@ibezkrovnyi Thank you for submitting this PR!

🔔 @DovydasNavickas @ferdaber @eps1lon - please review this PR in the next few days. Be sure to explicitly select Approve or Request Changes in the GitHub UI so I know what's going on.

If no reviewer appears after a week, a DefinitelyTyped maintainer will review the PR instead.

[typescript-bot]

@ibezkrovnyi The Travis CI build failed! Please review the logs for more information.

Once you've pushed the fixes, the build will automatically re-run. Thanks!

[ibezkrovnyi]

Issue

Issue is in enhancer4 of /types/recompose/recompose-tests.tsx
Some screenshots: #34706 (comment)
It looks like type inference an some point is broken now andunknown type is inferred.

Tested

After reverting my changes (using master branch):

typescript@3.4.3: ✔️ no issue
typescript@3.5.0-dev.20190404: ✔️ no issue
typescript@3.5.0-dev.20190409: ✔️ no issue
typescript@3.5.0-dev.20190411: ✔️ no issue
typescript@3.5.0-dev.20190412: ✖️ issue in recompose
typescript@3.5.0-dev.20190413: ✖️ issue in recompose
typescript@3.5.0-dev.20190416: ✖️ issue in recompose
typescript@3.5.0-dev.20190417: ✔️ no issue !

@RyanCavanaugh could you please advise what should I do - while issue with recompose isn't related to this PR, Travis CI build of this PR failed

[ferdaber]

ReadonlyArray<T> is already a subtype of Array<T>, so wouldn't this change make the parameter more restrictive for those who just have regular arrays?

[ibezkrovnyi]

@ferdaber

1. ReadonlyArray<T> is not subtype of Array<T>, it has no push, pop, shift, etc. Inside lib.es5.d.ts Array and ReadonlyArray are two separate interfaces.

2. ReadonlyArray is less restrictive, as it doesn't require from argument to have methods push, pop, etc.

3. Changed oneOf was tested with both ReadonlyArrays and with Arrays too and it works fine with both

Tested

This change was tested on my project and I used as const in part of code location, while keeping old way for another part of code locations. Both old and new ways work fine.

[ferdaber]

Derp, I went the opposite way. Sounds good, thanks for the clarification!

[ibezkrovnyi]

Removed non-consistent periods in JSDoc to trigger CI build

[typescript-bot]

A definition owner has approved this PR ⭐️. A maintainer will merge this PR shortly. If it shouldn't be merged yet, please leave a comment saying so and we'll wait. Thank you for your contribution to DefinitelyTyped!

[typescript-bot]

I just published @types/prop-types@15.7.1 to npm.