vant-weapp/packages/loading/index.ts

import { VantComponent } from '../common/component';
import { addUnit } from '../common/utils';

VantComponent({
  props: {
    size: {
      type: String,
      observer: 'setSizeWithUnit'
    },
    type: {
      type: String,
      value: 'circular'
    },
    color: {
      type: String,
      value: '#c9c9c9'
    }
  },

  data: {
    sizeWithUnit: '30px'
  },

  methods: {
    setSizeWithUnit(size: string | number): void {
      this.setData({
        sizeWithUnit: addUnit(size)
      });
    }
  }
});