Improved documentation and simplified logic

Author: jhollingworth

README.md

@@ -226,9 +226,9 @@ Connects a React component to a Redux store.
 
 #### Arguments
 
-* [`mapStateToProps(state, [props]): stateProps`] \(*Function*): If specified, the component will subscribe to Redux store updates. Any time it updates, `mapStateToProps` will be called. Its result must be a plain object, and it will be merged into the component’s props. If you omit it, the component will not be subscribed to the Redux store. If `props` is passed in as a second argument then `mapStateToProps` will be re-invoked whenever the component receives new props.
+* [`mapStateToProps(state, [ownProps]): stateProps`] \(*Function*): If specified, the component will subscribe to Redux store updates. Any time it updates, `mapStateToProps` will be called. Its result must be a plain object, and it will be merged into the component’s props. If you omit it, the component will not be subscribed to the Redux store. If `ownProps` is passed in as a second argument then `mapStateToProps` will be re-invoked whenever the component receives new props.
 
-* [`mapDispatchToProps(dispatch, [props]): dispatchProps`] \(*Object* or *Function*): If an object is passed, each function inside it will be assumed to be a Redux action creator. An object with the same function names, but bound to a Redux store, will be merged into the component’s props. If a function is passed, it will be given `dispatch`. It’s up to you to return an object that somehow uses `dispatch` to bind action creators in your own way. (Tip: you may use [`bindActionCreators()`](http://gaearon.github.io/redux/docs/api/bindActionCreators.html) helper from Redux.) If you omit it, the default implementation just injects `dispatch` into your component’s props. If `props` is passed in as a second argument then `mapStateToProps` will be re-invoked whenever the component receives new props.
+* [`mapDispatchToProps(dispatch, [ownProps]): dispatchProps`] \(*Object* or *Function*): If an object is passed, each function inside it will be assumed to be a Redux action creator. An object with the same function names, but bound to a Redux store, will be merged into the component’s props. If a function is passed, it will be given `dispatch`. It’s up to you to return an object that somehow uses `dispatch` to bind action creators in your own way. (Tip: you may use [`bindActionCreators()`](http://gaearon.github.io/redux/docs/api/bindActionCreators.html) helper from Redux.) If you omit it, the default implementation just injects `dispatch` into your component’s props. If `ownProps` is passed in as a second argument then `mapStateToProps` will be re-invoked whenever the component receives new props.
 
 * [`mergeProps(stateProps, dispatchProps, parentProps): props`] \(*Function*): If specified, it is passed the result of `mapStateToProps()`, `mapDispatchToProps()`, and the parent `props`. The plain object you return from it will be passed as props to the wrapped component. You may specify this function to select a slice of the state based on props, or to bind action creators to a particular variable from props. If you omit it, `{ ...parentProps, ...stateProps, ...dispatchProps }` is used by default.
 

src/components/createConnect.js

@@ -30,8 +30,8 @@ export default function createConnect(React) {
       wrapActionCreators(mapDispatchToProps) :
       mapDispatchToProps || defaultMapDispatchToProps;
     const finalMergeProps = mergeProps || defaultMergeProps;
-    const shouldUpdateStateProps = finalMapStateToProps.length >= 2;
-    const shouldUpdateDispatchProps = finalMapDispatchToProps.length >= 2;
+    const shouldUpdateStateProps = finalMapStateToProps.length > 1;
+    const shouldUpdateDispatchProps = finalMapDispatchToProps.length > 1;
 
     // Helps track hot reloading.
     const version = nextVersion++;