fix: Slider step prop not accepting null value (#26984)

* Fixes #26976 since rc-slider allows step to be null

* Fixes #26976 since rc-slider allows step to be null

* test: Slider step prop should not crash with undefined value

components/slider/__tests__/index.test.js

@@ -40,6 +40,44 @@ describe('Slider', () => {
     expect(wrapper.find('.ant-tooltip-content').length).toBe(0);
   });
 
+  it('when step is null, thumb can only be slided to the specific mark', () => {
+    const intentionallyWrongValue = 40;
+    const marks = {
+      0: '0',
+      48: '48',
+      100: '100',
+    };
+
+    const wrapper = mount(
+      <Slider marks={marks} defaultValue={intentionallyWrongValue} step={null} tooltipVisible />,
+    );
+    expect(wrapper.find('.ant-slider-handle').get(0).props).toHaveProperty('value', 48);
+  });
+
+  it('when step is not null, thumb can be slided to the multiples of step', () => {
+    const marks = {
+      0: '0',
+      48: '48',
+      100: '100',
+    };
+
+    const wrapper = mount(<Slider marks={marks} defaultValue={49} step={1} tooltipVisible />);
+    expect(wrapper.find('.ant-slider-handle').get(0).props).toHaveProperty('value', 49);
+  });
+
+  it('when step is undefined, thumb can be slided to the multiples of step', () => {
+    const marks = {
+      0: '0',
+      48: '48',
+      100: '100',
+    };
+
+    const wrapper = mount(
+      <Slider marks={marks} defaultValue={49} step={undefined} tooltipVisible />,
+    );
+    expect(wrapper.find('.ant-slider-handle').get(0).props).toHaveProperty('value', 49);
+  });
+
   it('should render in RTL direction', () => {
     const wrapper = mount(
       <ConfigProvider direction="rtl">
@@ -70,4 +108,9 @@ describe('Slider', () => {
       mount(<Slider value={value} tooltipVisible />);
     });
   });
+  it('step should not crash with undefined value', () => {
+    [undefined, null].forEach(value => {
+      mount(<Slider step={value} tooltipVisible />);
+    });
+  });
 });

components/slider/__tests__/type.test.tsx

@@ -29,4 +29,21 @@ describe('Slider.typescript', () => {
     );
     expect(result).toBeTruthy();
   });
+
+  it('step can be null value', () => {
+    const value = 0;
+    function onChange(v: number) {
+      return v;
+    }
+    const result = (
+      <Slider
+        defaultValue={value}
+        value={value}
+        onChange={onChange}
+        onAfterChange={onChange}
+        step={null}
+      />
+    );
+    expect(result).toBeTruthy();
+  });
 });

components/slider/index.tsx

@@ -32,7 +32,7 @@ export interface SliderBaseProps {
   reverse?: boolean;
   min?: number;
   max?: number;
-  step?: number;
+  step?: null | number;
   marks?: SliderMarks;
   dots?: boolean;
   included?: boolean;
@@ -143,6 +143,7 @@ const Slider = React.forwardRef<unknown, SliderSingleProps | SliderRangeProps>(
       return (
         <RcRange
           {...(restProps as SliderRangeProps)}
+          step={restProps.step!}
           className={cls}
           ref={ref}
           handle={(info: HandleGeneratorInfo) =>
@@ -159,6 +160,7 @@ const Slider = React.forwardRef<unknown, SliderSingleProps | SliderRangeProps>(
     return (
       <RcSlider
         {...(restProps as SliderSingleProps)}
+        step={restProps.step!}
         className={cls}
         ref={ref}
         handle={(info: HandleGeneratorInfo) =>