feat(Step): add finish-icon slot (#8241)

src/steps/test/__snapshots__/index.spec.tsx.snap

@@ -63,6 +63,19 @@ exports[`should change inactive icon when using inactive-icon prop 1`] = `
 </div>
 `;
 
+exports[`should render finish icon slot correctly 1`] = `
+<div class="van-hairline van-step van-step--horizontal van-step--finish">
+  <div class="van-step__title">
+    A
+  </div>
+  <div class="van-step__circle-container">
+    Custim Fiinsh Icon
+  </div>
+  <div class="van-step__line">
+  </div>
+</div>
+`;
+
 exports[`should render icon slot correctly 1`] = `
 <div class="van-steps van-steps--horizontal">
   <div class="van-steps__items">

src/steps/test/index.spec.tsx

@@ -90,3 +90,19 @@ test('should change finish icon when using finish-icon prop', () => {
   expect(firstStep.find('.van-icon-foo').exists()).toBeTruthy();
   expect(firstStep.html()).toMatchSnapshot();
 });
+
+test('should render finish icon slot correctly', () => {
+  const wrapper = mount({
+    render() {
+      return (
+        <Steps active={1}>
+          <Step v-slots={{ 'finish-icon': () => `Custim Fiinsh Icon` }}>A</Step>
+          <Step>B</Step>
+        </Steps>
+      );
+    },
+  });
+
+  const firstStep = wrapper.find('.van-step');
+  expect(firstStep.html()).toMatchSnapshot();
+});