TypeScript fixes for #1308 and #1309

[dfernandez-asapp]

Corresponding issue (if exists):

#1308
#1309

What would you like to add/fix?

This PR changes the type definition of createUseStyles<Theme>(styles, options?: CreateUseStyles) so it passes the Theme type parameters to the options type: createUseStyles<Theme>(styles, options?: CreateUseStyles<Theme>).

It also re-exports the Theming type, so users of createTheming can do explicit typing of the result: const theming : Theming = createTheming(... without having to add the theming package to the direct dependencies.

Todo

• Add tests if possible
• Add changelog if users should know about the change
• Add documentation

[kof]

Is this considered a breaking change?

[dfernandez-asapp]

Is not a breaking change:

• If you don't use TypeScript you are not affected by this.
• If you use TypeScript, expressions like createUseStyles<XYZ>(), createTheming(Context) or createTheming<XYZ>(Context) are not affected since the generic argument for the options will take a default (that is the same as before {}).

The main difference is that before this PR you can't pass a custom theming to createUseStyles in TypeScript without having to cast it to Theming<{}> and to cast it to Theming you need to import the type from the theming module.

A few things not included in the PR:

• I didn't add any tests, because I didn't see any typings tests (eg dtslint or tsd) in the project. This is a compile time check that cannot be tested with a normal unit test.
• I didn't do any change to Flow typings, I don't use Flow and I don't know if the Flow types definition has the same issue or not.

[kof]

I am going to merge it and release with the next release, but since I already released yesterday, I am gonna wait for more PRs to get merged.

[kof]

Merged, Thanks

[kof]

Released in v10.2.0