fix(Dropdown): search does not preserve value (#3584)

* Fix.

* add UT to cover case

src/modules/Dropdown/Dropdown.js

@@ -699,7 +699,7 @@ export default class Dropdown extends Component {
       this.handleChange(e, newValue)
     }
 
-    this.clearSearchQuery()
+    this.clearSearchQuery(value)
     this.closeOnChange(e)
 
     // Heads up! This event handler should be called after `onChange`
@@ -774,9 +774,12 @@ export default class Dropdown extends Component {
 
   // There are times when we need to calculate the options based on a value
   // that hasn't yet been persisted to state.
-  getMenuOptions = (value = this.state.value, options = this.props.options) => {
+  getMenuOptions = (
+    value = this.state.value,
+    options = this.props.options,
+    searchQuery = this.state.searchQuery,
+  ) => {
     const { additionLabel, additionPosition, allowAdditions, deburr, multiple, search } = this.props
-    const { searchQuery } = this.state
 
     let filteredOptions = options
 
@@ -890,20 +893,29 @@ export default class Dropdown extends Component {
   // Setters
   // ----------------------------------------
 
-  clearSearchQuery = () => {
+  clearSearchQuery = (value) => {
     debug('clearSearchQuery()')
+
+    const { searchQuery } = this.state
+    if (searchQuery === undefined || searchQuery === '') return
+
     this.trySetState({ searchQuery: '' })
+    this.setSelectedIndex(value, undefined, '')
   }
 
   setValue = (value) => {
     debug('setValue()', value)
     this.trySetState({ value })
   }
 
-  setSelectedIndex = (value = this.state.value, optionsProps = this.props.options) => {
+  setSelectedIndex = (
+    value = this.state.value,
+    optionsProps = this.props.options,
+    searchQuery = this.state.searchQuery,
+  ) => {
     const { multiple } = this.props
     const { selectedIndex } = this.state
-    const options = this.getMenuOptions(value, optionsProps)
+    const options = this.getMenuOptions(value, optionsProps, searchQuery)
     const enabledIndicies = this.getEnabledIndices(options)
 
     let newSelectedIndex

test/specs/modules/Dropdown/Dropdown-test.js

@@ -618,6 +618,26 @@ describe('Dropdown', () => {
     })
   })
 
+  describe('selectedIndex', () => {
+    it('sets "selectedIndex" when an item was selected', () => {
+      const option = _.last(options)
+
+      wrapperMount(<Dropdown options={options} search selection />)
+      const input = wrapper.find('input.search')
+
+      // open, simulate search and select option
+      wrapper.simulate('click')
+      input.simulate('change', { target: { value: option.text } })
+      domEvent.keyDown(document, { key: 'Enter' })
+
+      wrapper.should.have.state('selectedIndex', 4)
+
+      // open again
+      wrapper.simulate('click')
+      wrapper.should.have.state('selectedIndex', 4)
+    })
+  })
+
   describe('isMouseDown', () => {
     it('tracks when the mouse is down', () => {
       wrapperMount(<Dropdown />).simulate('mousedown')