fix(Alert): Fix transition prop to allow bools

src/Alert.tsx

@@ -77,8 +77,12 @@ const propTypes = {
    */
   closeLabel: PropTypes.string,
 
-  /** A `react-transition-group` Transition component used to animate the Alert on dismissal. */
-  transition: elementType,
+  /**
+   * Animate the alert dismissal. Defaults to using `<Fade>` animation or use
+   * `false` to disable. A custom `react-transition-group` Transition can also
+   * be provided.
+   */
+  transition: PropTypes.oneOfType([PropTypes.bool, elementType]),
 };
 
 const defaultProps = {

test/AlertSpec.js

@@ -43,6 +43,28 @@ describe('<Alert>', () => {
     ref.current.tagName.should.equal('DIV');
   });
 
+  it('should not have fade class when transition=false', () => {
+    const wrapper = mount(<Alert transition={false}>Message</Alert>);
+    expect(wrapper.find('.fade').length).to.equal(0);
+  });
+
+  it('should use Fade when transition=true', () => {
+    mount(
+      <Alert variant="danger" transition>
+        Message
+      </Alert>,
+    ).assertSingle('.fade');
+  });
+
+  it('should render null when transition and show are false', () => {
+    const wrapper = mount(
+      <Alert transition={false} show={false}>
+        Message
+      </Alert>,
+    );
+    expect(wrapper.isEmptyRender()).to.be.true;
+  });
+
   describe('Web Accessibility', () => {
     it('Should have alert role', () => {
       mount(<Alert>Message</Alert>).assertSingle('[role="alert"]');