Question

我在为访问sequelize函数而编写的通用BaseService类定义类型时遇到问题。这是我班级的样子：

import { Model, Column } from 'sequelize-typescript'
import { BuildOptions } from 'sequelize'

type ModelStatic = typeof Model & {
    new (values?: object, options?: BuildOptions): Model
}

abstract class EntityService<Entity = any> {
    readonly entity

    constructor(e) {
        this.entity = e
    }

    async findAll(q = undefined): Promise<Entity[]> {
        return await this.entity.findAll(q)
    }
}

class UserEntity extends Model<UserEntity> {
    @Column
    name: string
}

class UserService extends EntityService<UserEntity> {
    constructor() {
        super(UserEntity)
    }

    foo() {
        const users = this.findAll()
        //Use the users here
    }
}

我需要为通用类型Entity，属性entity和参数q定义类型。

上面的代码工作正常。对于键入，我进行了Entity extends Model<any>，然后将entity的类型设置为entity : ModelStatic；现在，我在输入this.entity.findAll()时得到建议，但是随后出现以下错误。

Type 'Model<any, any>' is not assignable to type 'Entity'.
  'Model<any, any>' is assignable to the constraint of type 'Entity', but 'Entity' could be instantiated with a different subtype of constraint 'Model<any, any>'.

我了解此错误的含义，但无法解决该问题。

键入通用续集实体

0 个答案: