我有以下容器：
// @flow
import { connect } from 'react-redux';
import { authLogin } from '../../redux/actions/authentication';
import UserAuthenticator from './UserAuthenticator';
function mapStateToProps({ authentication }) {
return {
validSession: authentication.validSession,
};
}
function mapDispatchToProps(dispatch) {
return {
authLogin: (email, password) => {
dispatch(authLogin(email, password));
},
};
}
export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
关于mapDispatchToProps部分：
src/components/UserAuthenticator/UserAuthenticatorContainer.js:21
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ function call. Function cannot be called on any member of intersection type
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^ intersection
Member 1:
v-------
52: declare function connect<A, OP>(
53: ...rest: Array<void> // <= workaround for https://github.com/facebook/flow/issues/2360
54: ): Connector<OP, $Supertype<{ dispatch: Dispatch<A> } & OP>>;
-----------------------------------------------------------^ polymorphic type: function type. See lib: flow-typed/npm/react-redux_v5.x.x.js:52
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^ function. This type is incompatible with
53: ...rest: Array<void> // <= workaround for https://github.com/facebook/flow/issues/2360
^^^^ undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:53
Member 2:
v-------
56: declare function connect<A, OP>(
57: mapStateToProps: Null,
58: mapDispatchToProps: Null,
...:
61: ): Connector<OP, $Supertype<{ dispatch: Dispatch<A> } & OP>>;
-----------------------------------------------------------^ polymorphic type: function type. See lib: flow-typed/npm/react-redux_v5.x.x.js:56
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^ function. This type is incompatible with
57: mapStateToProps: Null,
^^^^ union: null | undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:57
Member 1:
50: declare type Null = null | void;
^^^^ null. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^ function. This type is incompatible with
50: declare type Null = null | void;
^^^^ null. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Member 2:
50: declare type Null = null | void;
^^^^ undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^ function. This type is incompatible with
50: declare type Null = null | void;
^^^^ undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Member 3:
v--------------
63: declare function connect<S, A, OP, SP>(
64: mapStateToProps: MapStateToProps<S, OP, SP>,
65: mapDispatchToProps: Null,
...:
68: ): Connector<OP, $Supertype<SP & { dispatch: Dispatch<A> } & OP>>;
----------------------------------------------------------------^ polymorphic type: function type. See lib: flow-typed/npm/react-redux_v5.x.x.js:63
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^^^^ function. This type is incompatible with
65: mapDispatchToProps: Null,
^^^^ union: null | undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:65
Member 1:
50: declare type Null = null | void;
^^^^ null. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^^^^ function. This type is incompatible with
50: declare type Null = null | void;
^^^^ null. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Member 2:
50: declare type Null = null | void;
^^^^ undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^^^^ function. This type is incompatible with
50: declare type Null = null | void;
^^^^ undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Member 4:
v-----------
70: declare function connect<A, OP, DP>(
71: mapStateToProps: Null,
72: mapDispatchToProps: MapDispatchToProps<A, OP, DP>,
...:
75: ): Connector<OP, $Supertype<DP & OP>>;
------------------------------------^ polymorphic type: function type. See lib: flow-typed/npm/react-redux_v5.x.x.js:70
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^ function. This type is incompatible with
71: mapStateToProps: Null,
^^^^ union: null | undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:71
Member 1:
50: declare type Null = null | void;
^^^^ null. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^ function. This type is incompatible with
50: declare type Null = null | void;
^^^^ null. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Member 2:
50: declare type Null = null | void;
^^^^ undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^ function. This type is incompatible with
50: declare type Null = null | void;
^^^^ undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Member 5:
v------------------
77: declare function connect<S, A, OP, SP, DP>(
78: mapStateToProps: MapStateToProps<S, OP, SP>,
79: mapDispatchToProps: MapDispatchToProps<A, OP, DP>,
...:
82: ): Connector<OP, $Supertype<SP & DP & OP>>;
-----------------------------------------^ polymorphic type: function type. See lib: flow-typed/npm/react-redux_v5.x.x.js:77
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^^^^ function. Could not decide which case to select
79: mapDispatchToProps: MapDispatchToProps<A, OP, DP>,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ union type. See lib: flow-typed/npm/react-redux_v5.x.x.js:79
Case 1 may work:
20: declare type MapDispatchToProps<A, OP: Object, DP: Object> = ((dispatch: Dispatch<A>, ownProps: OP) => DP) | DP;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ function type. See lib: flow-typed/npm/react-redux_v5.x.x.js:20
But if it doesn't, case 2 looks promising too:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `DP` of function call
Please provide additional annotation(s) to determine whether case 1 works (or consider merging it with case 2):
13: function mapDispatchToProps(dispatch) {
^^^^^^^^ parameter `dispatch`
Member 6:
v---------------------
84: declare function connect<S, A, OP, SP, DP, P>(
85: mapStateToProps: MapStateToProps<S, OP, SP>,
86: mapDispatchToProps: Null,
...:
89: ): Connector<OP, P>;
------------------^ polymorphic type: function type. See lib: flow-typed/npm/react-redux_v5.x.x.js:84
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^^^^ function. This type is incompatible with
86: mapDispatchToProps: Null,
^^^^ union: null | undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:86
Member 1:
50: declare type Null = null | void;
^^^^ null. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^^^^ function. This type is incompatible with
50: declare type Null = null | void;
^^^^ null. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Member 2:
50: declare type Null = null | void;
^^^^ undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^^^^ function. This type is incompatible with
50: declare type Null = null | void;
^^^^ undefined. See lib: flow-typed/npm/react-redux_v5.x.x.js:50
Member 7:
v---------------------
91: declare function connect<S, A, OP, SP, DP, P>(
92: mapStateToProps: MapStateToProps<S, OP, SP>,
93: mapDispatchToProps: MapDispatchToProps<A, OP, DP>,
...:
96: ): Connector<OP, P>;
------------------^ polymorphic type: function type. See lib: flow-typed/npm/react-redux_v5.x.x.js:91
Error:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^^^^ function. Could not decide which case to select
93: mapDispatchToProps: MapDispatchToProps<A, OP, DP>,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ union type. See lib: flow-typed/npm/react-redux_v5.x.x.js:93
Case 1 may work:
20: declare type MapDispatchToProps<A, OP: Object, DP: Object> = ((dispatch: Dispatch<A>, ownProps: OP) => DP) | DP;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ function type. See lib: flow-typed/npm/react-redux_v5.x.x.js:20
But if it doesn't, case 2 looks promising too:
21: export default connect(mapStateToProps, mapDispatchToProps)(UserAuthenticator);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `DP` of function call
Please provide additional annotation(s) to determine whether case 1 works (or consider merging it with case 2):
13: function mapDispatchToProps(dispatch) {
^^^^^^^^ parameter `dispatch`
Found 1 error
我无法理解这个问题是什么。我做错了什么？
答案 0 :(得分：3)
我相信您需要为dispatch添加类型注释。例如：
function mapDispatchToProps(dispatch: Dispatch) {
return {
authLogin: (email, password) => {
dispatch(authLogin(email, password));
}
};
}
这假设您已安装react-redux流程库定义（您应该使用flow-typed）。否则，请尝试：
function mapDispatchToProps(dispatch: Function) {
return {
authLogin: (email, password) => {
dispatch(authLogin(email, password));
}
};
}