vant/src/steps/index.js

import { createNamespace } from '../utils';
import { GREEN } from '../utils/color';

const [createComponent, bem] = createNamespace('steps');

export default createComponent({
  props: {
    inactiveIcon: String,
    active: {
      type: Number,
      default: 0
    },
    direction: {
      type: String,
      default: 'horizontal'
    },
    activeColor: {
      type: String,
      default: GREEN
    },
    activeIcon: {
      type: String,
      default: 'checked'
    }
  },

  data() {
    return {
      steps: []
    };
  },

  render(h) {
    return (
      <div class={bem([this.direction])}>
        <div class={bem('items')}>{this.slots()}</div>
      </div>
    );
  }
});