微信小程序swith bug

 findIndex(a, b) {
        let value = null
        var key = null
        if (a != -1) {
            switch (a) {
                case 0:
                    key = 'human'
                    switch (b) {
                        case 0:
                            key = 'human'
                            value = this.tName()
                            break;
                        case 1:
                            value = '!human'
                            break;
                    }
                    break;
                case 1:
                    key = 'date'
                    switch (b) {
                        case 0:
                            value = this.tDateTime(0)
                            break;
                        case 1:
                            value = this.tDateTime(1)
                            break;
                        case 2:
                            value = this.tDateTime(-1)
                            break;
                        default:
                            break;
                    }
                    break;
                default:
                    key = 'other'
                    break;
            }
            return [{
                key: value
            }]
        }

    },

如图，key变量点不亮，return返回的是一个字符串‘key’

最终采用了if格式解决，简直完美。。。