validate.js返回错误“未知验证程序模式”

我试图使用validate.js验证前端的输入,然后再使用node将其输入到数据库中,但是我得到了一个无法识别的错误。我已经检查了文档,相信我设置的约束是正确的。准确的错误是:

message:"Unknown validator pattern"

我的验证器设置如下:

                    let alphanumeric = /^[a-zA-Z0-9]*$/;
                    let constraints = {
                        clientUsername:{
                            presence: true,
                            length: {min:8, max:15},
                            pattern:alphanumeric,
                            message: 'make sure client username is between 8-15 characters, is only numbers and letters'
                        },
                        tileCategory:{
                            presence:true,
                            length:{min:1, max:1},
                            numericality:{
                                onlyInteger:true,
                                lessThanOrEqualTo:tileCategoryNumber,
                            },
                            message:'enter a number, 1 char in length, less than or equal to 3' //the current number of tiles
                        }
                    };

                    validate({clientUsername: input.clientUsername},constraints);

起初我以为这是regex模式,但试着把它注释掉,然后它说

message:"Unknown validator messsage"

所以我猜我的验证器总的来说有点问题。

在最上面我当然包括 const validate = require('validate.js');