fix(VCombobox): don't add empty values (#13298)

fixes #13274

Author: vibhash-singh

packages/vuetify/src/components/VCombobox/VCombobox.ts

@@ -214,10 +214,10 @@ export default VAutocomplete.extend({
 
       // If the user is not searching
       // and no menu item is selected
+      // or if the search is empty
       // do nothing
-      if (menuIndex < 0 &&
-        !this.searchIsDirty
-      ) return
+      if ((menuIndex < 0 && !this.searchIsDirty) ||
+          !this.internalSearch) return
 
       if (this.editingIndex > -1) {
         return this.updateEditing()

packages/vuetify/src/components/VCombobox/__tests__/VCombobox-multiple.spec.ts

@@ -455,4 +455,32 @@ describe('VCombobox.ts', () => {
     await wrapper.vm.$nextTick()
     expect(change).toHaveBeenLastCalledWith(['foo', 'bar'])
   })
+
+  // https://github.com/vuetifyjs/vuetify/issues/13274
+  it('should not add empty values', async () => {
+    const { wrapper, change } = createMultipleCombobox({
+      chips: true,
+      multiple: true,
+      items: ['foo'],
+      value: ['foo'],
+    })
+
+    const input = wrapper.find('input')
+    const element = input.element as HTMLInputElement
+
+    // Add a value and then remove it
+    input.trigger('focus')
+    element.value = 'a'
+    input.trigger('input')
+    await wrapper.vm.$nextTick()
+    element.value = ''
+    input.trigger('input')
+    await wrapper.vm.$nextTick()
+
+    // Lose focus
+    input.trigger('keydown.tab')
+    await wrapper.vm.$nextTick()
+
+    expect(change).not.toHaveBeenCalled()
+  })
 })