如何在 Jasmine 中测试 Sequelize？答案

【问题标题】：How to test Sequelize in Jasmine?如何在 Jasmine 中测试 Sequelize？
【发布时间】：2021-06-08 16:27:03
【问题描述】：

我使用以下代码在database/index.ts 文件中初始化一个sequelize db：

import { Sequelize } from 'sequelize';

const {
  DATABASE_DIALECT,
  DATABASE_HOST,
  DATABASE_PORT,
  DATABASE_USER_NAME,
  DATABASE_USER_PASSWORD,
  DATABASE_NAME,
  ENVIRONMENT
} = process.env;

const sequelize = new Sequelize({
  host: DATABASE_HOST,
  port: +(DATABASE_PORT as string),
  dialect: DATABASE_DIALECT as 'postgres',
  database: DATABASE_NAME,
  username: DATABASE_USER_NAME,
  password: DATABASE_USER_PASSWORD,
  logging:
    (ENVIRONMENT as string) === 'production' || (ENVIRONMENT as string) === 'acceptance'
      ? false
      : console.log,
  query: {
    raw: true // Receive a plain object/array as a response from Sequelize (default response contains a lot of Sequelize metadata)
  }
});


export default sequelize;

我需要测试 logging 属性，因为它由检查 ENV 的三元运算符确定。为了测试这一点，我需要检查调用 new Sequelize(...) 的参数。

如何在 Jasmine 中做到这一点？我阅读了很多文章，看起来我们无法监视 Sequelize 类本身来检查调用参数。

【问题讨论】：

标签： javascript node.js postgresql unit-testing sequelize.js

【解决方案1】：

我没有大量使用 Sequelize，但传递给 logging 的值似乎最终在 sequelize.options.logging 之下（基于 https://github.com/sequelize/sequelize/blob/main/lib/sequelize.js#L277）。所以在测试中引用sequelize.options.logging 可能是最快的方法。

另一种方法可能是将对象文字（传递给Sequelize 构造函数）存储在变量中。然后导出变量（使其在测试中可用）并将变量传递给Sequelize（继续实例化）。比如：

export const sequelizeOptions = {
  host: DATABASE_HOST,
  port: +(DATABASE_PORT as string),
  dialect: DATABASE_DIALECT as 'postgres',
  database: DATABASE_NAME,
  username: DATABASE_USER_NAME,
  password: DATABASE_USER_PASSWORD,
  logging:
    (ENVIRONMENT as string) === 'production' || (ENVIRONMENT as string) === 'acceptance'
      ? false
      : console.log,
  query: {
    raw: true // Receive a plain object/array as a response from Sequelize (default response contains a lot of Sequelize metadata)
  }
};

const sequelize = new Sequelize(sequelizeOptions);

export default sequelize;

理论上，上述内容应该与您现在所拥有的相同。唯一不同的是它捕获并暴露了对象。

另一种方法可能是在console.log 周围创建一个瘦包装器，以便您可以监视包装器——然后将包装器作为构造函数选项的一部分传递：

export const logger = (...args: any[]) => console.log(...args);

const sequelize = new Sequelize({
  host: DATABASE_HOST,
  port: +(DATABASE_PORT as string),
  dialect: DATABASE_DIALECT as 'postgres',
  database: DATABASE_NAME,
  username: DATABASE_USER_NAME,
  password: DATABASE_USER_PASSWORD,
  logging:
    (ENVIRONMENT as string) === 'production' || (ENVIRONMENT as string) === 'acceptance'
      ? false
      : logger,
  query: {
    raw: true // Receive a plain object/array as a response from Sequelize (default response contains a lot of Sequelize metadata)
  }
});

【讨论】：