[react-redux] libdef incompatible with flow v0.85

The todos-flow example just works with flow v0.78 and the current flow-typed react-redux types, but after upgrading to flow v0.85 there are a lot of flow errors I am not able to fix.

Full repo here and full error log here.

> todos-flow@0.0.1 flow 
> flow

Error ------------------------------------------------------------------------------- src/containers/FilterLink.js:29:19

Missing type annotation for `CP`. `CP` is a type parameter declared in function type [1] and was implicitly instantiated
at call of `connect` [2].

   src/containers/FilterLink.js:29:19
                          v-------
    29| const connector = connect(
    30|   mapStateToProps,
    31|   mapDispatchToProps
    32| );
        ^ [2]

References:
   flow-typed/npm/react-redux_v5.x.x.js:133:34
                                         v
   133|   declare export function connect<
   134|     Com: ComponentType<*>,
   135|     A,
   136|     S: Object,
   137|     DP: Object,
   138|     SP: Object,
   139|     RSP: Object,
   140|     RDP: Object,
   141|     CP: $Diff<$Diff<ElementConfig<Com>, RSP>, RDP>,
   142|     ST: $Subtype<{[_: $Keys<Com>]: any}>
   143|     >(
   144|     mapStateToProps: MapStateToProps<S, SP, RSP>,
   145|     mapDispatchToProps: MapDispatchToProps<A, DP, RDP>
   146|   ): (component: Com) => ComponentType<CP & SP & DP> & $Shape<ST>;
          --------------------------------------------------------------^ [1]


Error ------------------------------------------------------------------------------- src/containers/FilterLink.js:29:19

Missing type annotation for `DP`. `DP` is a type parameter declared in function type [1] and was implicitly instantiated
at call of `connect` [2].

   src/containers/FilterLink.js:29:19
                          v-------
    29| const connector = connect(
    30|   mapStateToProps,
    31|   mapDispatchToProps
    32| );
        ^ [2]

References:
   flow-typed/npm/react-redux_v5.x.x.js:133:34
                                         v
   133|   declare export function connect<
   134|     Com: ComponentType<*>,
   135|     A,
   136|     S: Object,
   137|     DP: Object,
   138|     SP: Object,
   139|     RSP: Object,
   140|     RDP: Object,
   141|     CP: $Diff<$Diff<ElementConfig<Com>, RSP>, RDP>,
   142|     ST: $Subtype<{[_: $Keys<Com>]: any}>
   143|     >(
   144|     mapStateToProps: MapStateToProps<S, SP, RSP>,
   145|     mapDispatchToProps: MapDispatchToProps<A, DP, RDP>
   146|   ): (component: Com) => ComponentType<CP & SP & DP> & $Shape<ST>;
          --------------------------------------------------------------^ [1]

[peter-leonov]

@zanettin @villesau here is a promised PR #3012 😅

I’d say the adapted typings are production ready now. They support options and mergeProps arguments to connect() with proper connection to the component props and mapStateToProps, own props, etc. Most of the type arguments can be requested to be inferred with the new _ type placeholder.

[jbrown215]

I think @peter-leonov did a really good job with https://gist.github.com/peter-leonov/e1fac25b6ade9b28c03c213e8a9d7121.

With these types, you should have OwnProps, StateProps, and DispatchProps (OP, SP, and DP) all be exact object types. In your component that combines all three of these types, use:

type Props = {| ...OwnProps, ...StateProps, ...DispatchProps |}

It’s important that you don’t use intersection with exact objects, since that will produce an empty type.