add test cases

packages/material-ui/src/Slider/Slider.test.js

@@ -1123,4 +1123,47 @@ describe('<Slider />', () => {
     render(<SliderUnstyled tabIndex={-1} value={30} />);
     expect(screen.getByRole('slider')).to.have.property('tabIndex', -1);
   });
+
+  describe('prop: disableSwap', () => {
+    it('should bound the value when using the keyboard', () => {
+      const handleChange = spy();
+      const { getAllByRole } = render(
+        <Slider defaultValue={[20, 30]} disableSwap onChange={handleChange} />,
+      );
+      const [slider1, slider2] = getAllByRole('slider');
+
+      act(() => {
+        slider1.focus();
+        fireEvent.change(slider2, { target: { value: '19' } });
+      });
+      expect(handleChange.args[0][1]).to.deep.equal([20, 20]);
+      expect(document.activeElement).to.have.attribute('data-index', '1');
+    });
+
+    it('should bound the value when using the mouse', () => {
+      const handleChange = spy();
+      const { container } = render(
+        <Slider defaultValue={[20, 30]} disableSwap onChange={handleChange} />,
+      );
+
+      stub(container.firstChild, 'getBoundingClientRect').callsFake(() => ({
+        width: 100,
+        height: 10,
+        bottom: 10,
+        left: 0,
+      }));
+
+      fireEvent.touchStart(
+        container.firstChild,
+        createTouches([{ identifier: 1, clientX: 35, clientY: 0 }]),
+      );
+      fireEvent.touchMove(
+        document.body,
+        createTouches([{ identifier: 1, clientX: 19, clientY: 0 }]),
+      );
+      expect(handleChange.args[0][1]).to.deep.equal([20, 35]);
+      expect(handleChange.args[1][1]).to.deep.equal([20, 20]);
+      expect(document.activeElement).to.have.attribute('data-index', '1');
+    });
+  });
 });