TypeScript support?

[kamilszewczyk0]

Is library compatible with TypeScript? Any extensions for types?

[valepu]

There is a bit of a problem with the @types.
The DefinitelyTyped package for is_js seems to be @types/is (i have tried @types/is_js @types/is-js @types/is.js @types/isjs but they don't exist), and the method calls seem correct, but if i import it like this:

import * as is from 'is_js';

i get an error saying it can't find the type definition when building (despite VS code not giving me any error). if i import it like this

import * as is from 'is';

I get a different error. The solution seems to be to install is_js with an alias: "is": "npm:is_js@^0.9.0", and then import the module like this import * as is from 'is';

if i do like this it seems to work but maybe i'm doing something completely wrong

[shivam-tripathi]

@valepu https://www.npmjs.com/package/is and https://www.npmjs.com/package/is_js are two entirely different libraries.

[valepu]

@valepu https://www.npmjs.com/package/is and https://www.npmjs.com/package/is_js are two entirely different libraries.

@shivam-tripathi Yes, but the types are for is_js despite being called @types/is.
I can confirm this because the function is.existy is available in "is_js" but not in "is". On top of that if you check the file https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/is/index.d.ts you can read the following

// Type definitions for is.js
// Project: http://arasatasaygin.github.io/is.js/
// Definitions by: Rodrigo Cabral <https://github.com/cabralRodrigo>, Mitchell Grice <https://github.com/gricey432>
// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped

[lancedolan]

To illustrate that @valepu is correct and there is a mismatch here:

1. navigate to https://www.npmjs.com/package/@types/is
2. Read :

   This package contains type definitions for is.js (http://arasatasaygin.github.io/is.js/).

3. navigate to http://arasatasaygin.github.io/is.js
4. click "View On Github", navigates to https://github.com/arasatasaygin/is.js
5. Notice that the package name used in the readme directions is is_js

[lancedolan]

Well I buckled and switched from is_js to is purely for easy typescript support, though I preferred the is_js api.

Also type definitions in @types/is aren't typeguard-friendly. I believe should be (x:unknown) : x is string and not (x:unknown) : boolean. Might log issue in that repo.

[lancedolan]

Update: I discovered that @types/is exports their types for both modules is and is_js.

https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/is/index.d.ts#L1377-L1383

That can't be right.