React-Native Realm DB调试模式插入报错：_id需为uuid类型（发布模式正常）

问题现象 #

• 调试模式（Metro/VSCode调试器）下插入带UUID主键的CreditCard对象时，抛出类型错误：

EconomeApp ERROR Log Start Fri Aug 26 2022 17:41:44 GMT+0300 (Israel Daylight Time)
Realm write ERROR: Error: CreditCard._id must be of type 'uuid', got 'object' ([object Object])
stack:
create@[native code]
anonymous@[native code]
write@[native code]
EconomeApp ERROR Log End

• 发布模式下插入操作完全正常，日志显示对象创建成功：

LOG  Running "EconomeApp" with {"rootTag":61}
LOG  EconomeApp Log Start Fri Aug 26 2022 17:47:25 GMT+0300 (IDT)
created one card: d6ce1d14-0dc0-43db-8b6b-c4f04f85aa41
EconomeApp Log End
LOG  EconomeApp Log Start Fri Aug 26 2022 17:47:25 GMT+0300 (IDT)
Realm written successfuly
EconomeApp Log End

问题原因 #

调试模式下，Metro会在调试器与应用之间对JS对象进行序列化/反序列化处理，导致Realm.BSON.UUID实例被转换为普通JS对象，Realm无法识别其为UUID类型，从而触发类型校验错误。发布模式下无此序列化过程，原生代码直接处理UUID实例，因此可以正常工作。

解决方案 #

方案1：传递UUID字符串替代UUID实例 #

插入时将UUID转换为字符串传入，Realm会自动解析为UUID类型：

this._writeToDB(() => {
    const uuid = new Realm.BSON.UUID();
    const card1 = this._realmObject.create(CollectionTypes.CreditCard.schema.name, {
        _id: uuid.toString(),
        lastPaidDate: new Date(),
        cardLimit: new Realm.BSON.Decimal128("123.5123"),
        lastFourDigits: "1234",
        isManualPayment: false,
        dayCycle: 15
    });
    Helper.log(`created one card: ${card1._id}`);
});

方案2：修改Schema默认值为函数形式 #

Schema中_id的默认值不要直接实例化UUID，改用延迟执行的函数，避免调试模式下提前序列化：

export class CreditCard {
    // ... 构造函数保持不变
    static schema = {
        name: "CreditCard",
        primaryKey: '_id',
        properties: {
            _id: {type: "uuid", default: () => new Realm.BSON.UUID()}, // 改为函数延迟生成
            lastpaidDate: { type: "date", default: () => new Date() }, // 日期默认值同理优化
            cardLimit: { type: "decimal128", default: Defenitions.undefinedDecimalValue },
            lastFourDigits: { type: "string", default: Defenitions.undefinedString },
            isManualPayment: { type: "bool", default: Defenitions.defaultManualPayment },
            dayCycle: { type: "int", default: Defenitions.defaultDayCycle }
        },
    };
}

方案3：直接使用字面量对象插入 #

避免实例化自定义CreditCard类，直接传入符合Schema的字面量对象，减少序列化问题：

this._writeToDB(() => {
    // 利用Schema中_id的默认值自动生成UUID
    const card1 = this._realmObject.create(CollectionTypes.CreditCard.schema.name, {
        lastPaidDate: new Date(),
        cardLimit: new Realm.BSON.Decimal128("123.5123"),
        lastFourDigits: "1234",
        isManualPayment: false,
        dayCycle: 15
    });
    Helper.log(`created one card: ${card1._id}`);
});

额外注意点 #

代码中CreditCard构造函数的参数lastPaidDate与Schema中的lastpaidDate大小写不一致，会导致该字段赋值失败，建议统一命名规则，避免潜在bug。

内容的提问来源于stack exchange，提问作者Ethan K