[fixed] Reset highlightedIndex when it's outside of items.length

lib/Autocomplete.js

@@ -62,8 +62,17 @@ let Autocomplete = React.createClass({
     this._performAutoCompleteOnKeyUp = false
   },
 
-  componentWillReceiveProps () {
+  componentWillReceiveProps (nextProps) {
     this._performAutoCompleteOnUpdate = true
+    // If `items` has changed we want to reset `highlightedIndex`
+    // since it probably no longer refers to a relevant item
+    if (this.props.items !== nextProps.items ||
+      // The entries in `items` may have been changed even though the
+      // object reference remains the same, double check by seeing
+      // if `highlightedIndex` points to an existing item
+      this.state.highlightedIndex >= nextProps.items.length) {
+      this.setState({ highlightedIndex: null })
+    }
   },
 
   componentDidUpdate (prevProps, prevState) {

lib/__tests__/Autocomplete-test.js

@@ -60,6 +60,21 @@ describe('Autocomplete acceptance tests', () => {
 
   });
 
+  it('should reset `highlightedIndex` when `items` changes', () => {
+    autocompleteWrapper.setState({ highlightedIndex: 10 });
+    autocompleteWrapper.setProps({ items: [] });
+    expect(autocompleteWrapper.state('highlightedIndex')).toBe(null);
+  });
+
+  it('should reset `highlightedIndex` when it falls outside of possible `items` range', () => {
+    const items = getStates();
+    autocompleteWrapper.setProps({ items });
+    autocompleteWrapper.setState({ highlightedIndex: 10 });
+    items.length = 5;
+    autocompleteWrapper.setProps({ items });
+    expect(autocompleteWrapper.state('highlightedIndex')).toBe(null);
+  });
+
 });
 
 // Event handler unit tests