fix Select[multipie] with OptGroup will cause error.

src/util.js

@@ -8,7 +8,10 @@ export function getValuePropValue(child) {
   if (child.key) {
     return child.key;
   }
-  throw new Error(`no key or value for ${child}`);
+  if (child.type && child.type.isSelectOptGroup && props.label) {
+    return props.label;
+  }
+  throw new Error(`no key or value or label(only for OptGroup) for ${child}`);
 }
 
 export function getPropValue(child, prop) {

tests/Select.multiple.spec.js

@@ -67,4 +67,22 @@ describe('Select.multiple', () => {
       expect(handleFocus).toBeCalled();
     });
   });
+
+  it('OptGroup without key', () => {
+    expect(() => {
+      mount(
+        <Select
+          multiple
+          defaultValue={['1']}
+        >
+          <OptGroup label="group1">
+            <Option value="1">One</Option>
+          </OptGroup>
+          <OptGroup label="group2">
+            <Option value="2">Two</Option>
+          </OptGroup>
+        </Select>,
+      );
+    }).not.toThrow();
+  });
 });

tests/util.spec.js

@@ -1,5 +1,5 @@
 /* eslint-disable no-undef */
-import { includesSeparators, splitBySeparators } from '../src/util';
+import { includesSeparators, splitBySeparators, getValuePropValue } from '../src/util';
 
 describe('includesSeparators', () => {
   const separators = [' ', ','];
@@ -38,3 +38,27 @@ describe('splitBySeparators', () => {
     expect(splitBySeparators(string, separators)).toEqual([]);
   });
 });
+
+describe('getValuePropValue', () => {
+  const errorSpy = jest.spyOn(console, 'error').mockImplementation(() => {});
+
+  afterEach(() => {
+    errorSpy.mockReset();
+  });
+
+  afterAll(() => {
+    errorSpy.mockRestore();
+  });
+
+  it('return label when type is isSelectOptGroup', () => {
+    expect(getValuePropValue({
+      props: {
+        label: 'Manager',
+      },
+      type: {
+        isSelectOptGroup: true,
+      },
+    })).toBe('Manager');
+    expect(errorSpy).not.toHaveBeenCalled();
+  });
+});