Fix TypeScript type definitions

[alvivi]

Typescript type declarations are broken, at least from typescript 2.0.3 (I have not tried other versions). This pull request makes this project usable from typescript.

[acstll]

Thank you @alvivi

Maybe this needs a bit more work:

https://github.com/snabbdom/snabbdom-to-html/blob/master/type-definitions/snabbdom-to-html.d.ts#L4

I'm not a TypeScript user myself so there's some syntax details I don't control. Map is the native ES2015 implementation so its arguments can vary, like being <string, number>, <string> or nothing… I think there's typings for this ES2015 stuff, maybe adding the Map one will be the most useful? What do you think?

Thanks again.

[alvivi]

@acstll, yes, this needs more work. But IMHO, the problem is not with Map.

Map type declaration is bundled with Typescript. You can read the definition here. You can use Map from typescript when targeting ES6 or adding the lib "es2015.collection" and supplying a polyfill.

The Map declaration in Typescript is generic; that is why you cannot use Map without its type parameters. All type parameters must be defined to use a generic type, so you cannot use something like Map<string> or Map. Maybe the type Map<string, string> is too restrictive. Reading the code seems that the only type used for keys are strings. For value types, is the same. If there is any other possible type for values we can use something like Map<string, any> or Map<string, string | string[]>.

There are still problems using this library from Typescript. First I cannot use the default toHTML function because of this. Second, I think that the definition of VNode is not correct. However, that definition comes from Sanbbdom itself. The field sel is marked as required, but that is not true, because I can create valid VNodes with no sel, like {text: "hello world"}. This fork has a proper VNode definition.

[TylorS]

@alvivi If/When you feel you've got decent typings here, feel free to ping me and I'll review them. I wrote them without ever actually using this library, but for supporting TypeScript and to do server-side rendering for (Motor)Cycle.js. snabbdom-ts is temporarily a fork I've written, but it will be mainlined in the future when I have the time.

[acstll]

@alvivi thanks for the explanation.

The style module can take numbers.

https://github.com/snabbdom/snabbdom-to-html/blob/master/modules/style.js#L21
https://github.com/snabbdom/snabbdom-to-html/blob/master/test/index.js#L66

and also, in theory, inside a custom module you could just call attributes(key) to get a value already in the map, and do stuff based on that, and that would be it :-)

Maybe Map<string, string|number> fits all that?

As for the problem with the VNode definition, as @TylorS suggests, there's a plan to port Snabbdom to TypeScript (snabbdom/snabbdom#150), but we don't know exactly when that will happen.

In fact, we also wanted to port this library to TypeScript (I have a branch with a first try, maybe I could push it so you can review/test it if you feel like it), but just haven't got the time to work on that.

[TylorS]

@acstll I'll get into gear soon, just finished moving, and should be getting back to normal shortly :)

[acstll]

@TylorS no worries, I know moving takes tons of time. It will be great to have you back to "normal" 😄