Heterogeneous selectors typings

[toomuchdesign]

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

feature

What is the current behaviour? (You can also link to an open issue here)

Heterogeneous selectors and any number of uniform selectors not implemented.

What is the new behaviour?

dependencies property added in typing, supported heterogeneous selectors and any number of uniform selectors.

We mainly replicate what happened in reselect typing here and here.

Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

I think so, because the reselect for similar changes made it.

Other information:

see conversation in #60

Please check if the PR fulfills these requirements:

• Tests for the changes have been added
• Docs have been added / updated

[coveralls]

Coverage remained the same at 100.0% when pulling c89f348 on heterogeneous-selectors-typings into aaf3561 on master.

[xsburg]

Hi @toomuchdesign!
Sorry for not participating in the original discussion.
The changes seem perfectly valid to me, we are basically following the typings in reselect and even go a bit forward by adding support to the dependencies property.
A few notes about the maintainability of the typings and breaking changes.

Maintainability

The typings are of course getting bigger with this PR, but it seems to be the only way to keep backward compatibility with the previous version. As mentioned in the original discussion in reselect, otherwise we break code that used type parameters. There are also use cases where the original typings are just easier to use, so looks like we have to keep both. The maintainability will of course suffer, but it seems the only way forward.

Breaking changes

In general, I cannot see any breaking changes, given that we keep both typings (the way it is in this PR). But to play it safe, I would rather follow reselect example and bump the version.

All in all, I'm glad that we keep up to date with reselect typings and look forward to try it in work! 👌

[sgrishchenko]

@xsburg hello, what you think about #65 PR (this is an attempt to generate types automatically)? This should improve maintainability.
And you says, that there are also use cases where the original typings are just easier to use. Whitch original typings you mean? Homogeneous selectors? If yes, can you give an example, please? It just seems to me that heterogeneous selectors are a more general version of homogeneous selectors?