vant/src/checkbox-group/index.js

import { createNamespace } from '../utils';
import { FieldMixin } from '../mixins/field';
import { ParentMixin } from '../mixins/relation';

const [createComponent, bem] = createNamespace('checkbox-group');

export default createComponent({
  mixins: [ParentMixin('vanCheckbox'), FieldMixin],

  props: {
    max: [Number, String],
    disabled: Boolean,
    direction: String,
    iconSize: [Number, String],
    checkedColor: String,
    value: {
      type: Array,
      default: () => [],
    },
  },

  watch: {
    value(val) {
      this.$emit('change', val);
    },
  },

  methods: {
    // @exposed-api
    toggleAll(options = {}) {
      if (typeof options === 'boolean') {
        options = { checked: options };
      }

      const { checked, skipDisabled } = options;

      const children = this.children.filter((item) => {
        if (item.disabled && skipDisabled) {
          return item.checked;
        }
        return checked ?? !item.checked;
      });

      const names = children.map((item) => item.name);
      this.$emit('input', names);
    },
  },

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