模拟枚举

function isThisType(val){
    for(let key in this){
        if(this[key] === val){
            return true
        }
    }
    return false
}

const LoginType = {
    USER_MINI_PROGRAM:100,
    USER_EMAIL:101,
    USER_MOBILE:102,
    ADMIN_EMAIL:200,
    isThisType
}

const ArtType = {
    MOVIE:100,
    MUSIC:200,
    SENTENCE:300,
    BOOK:400,
    isThisType
}

module.exports = {
    LoginType,
    ArtType
}

使用：

router.post('/', async (ctx) => {
    const v = await new TokenValidator().validate(ctx)
    let token;
    switch (v.get('body.type')) {
        case LoginType.USER_EMAIL:
            token = await emailLogin(v.get('body.account'),
                v.get('body.secret'))
            break
        case LoginType.USER_MINI_PROGRAM:
            token = await WXManager.codeToToken(v.get('body.account'))
            break
        case LoginType.ADMIN_EMAIL:
            break
        default:
            throw new global.errs.ParameterException('没有相应的处理函数')
    }
    ctx.body = {
        token
    }
})