在Cypress（mysql2）中测试时无法连接到MySQL数据库

Question

运行集成测试时出现错误：

0 passing (17s)
   1 failure

   1) Registration page
        register new users allowed and update status in the database:
      TypeError: Net.connect is not a function
       at new Connection (webpack:///./node_modules/mysql2/lib/connection.js:50:0)
       at ./node_modules/mysql2/index.js.exports.createConnection (webpack:///./node_modules/mysql2/index.js:10:0)
       at Context.eval (webpack:///./cypress/integration/registration.spec.js:23:34)

这是我的环境：

MySQL Workbench
MySQL Server 8.0.29

我提出了本地后端，我可以访问数据库。这是我的代码：

const mysql2 = require('mysql2');

describe('Registration page', () => {
     beforeEach(() => {
         // visit the registration page
         cy.visit('http://localhost:3000/registration');
     });

     it('register new users allowed and update status in the database', () => {
         // fill out the registration form
         cy.get('input[name="fullName"]').type("Nazar Dmytryshyn")
         cy.get('input[type="email"]').type('testuser@example.com');
         cy.get('input[name="pwd"]').type('testpassword');
         cy.get('input[name="confirmPassword"]').type('testpassword');

         // submit the form
         cy.get('button[class="btn btn-success"]').click();

         // check that the user is redirected to the login page
         cy.url().should('include', '/login');

         // create a connection to the test database
         const connection = mysql2.createConnection({
             host: '127.0.0.1:3306',
             user: 'root',
             password: 'rootpassword',
             database: 'local1'
         });

         // open the connection
         connection.connect();

         // update the developer status in the database
         connection.query(
             'UPDATE `main_backendless`.`Developer` SET `developerStatusId` = "1" WHERE (`email` = "testuser@example.com")',
             (error, results) => {
                 if (error) throw error;
                 expect(results.affectedRows).to.equal(1);
             }
         );

         // close the connection
         connection.end();
     });
});

我检查了这个数据10次，它是正确的，我可以通过MySQL WorkBench连接到数据库

host: '127.0.0.1:3306',
             user: 'root',
             password: 'rootpassword',
             database: 'main_backendless'

我将感激任何可以实现的想法！

Answer 1

我建议使用cypress-mysql，它为您隐藏了很多实现细节。

如果您尝试滚动自己的任务，则可能会得到未定义的返回值。

安装

npm install cypress-mysql

//or

yarn add cypress-mysql 

配置

发行说明已过时，以下是 Cypress 10+ 的配置

// cypress.config.js

const { defineConfig } = require("cypress");
const mysql = require('cypress-mysql');

module.exports = defineConfig({
  // ...
  e2e: {
    setupNodeEvents(on, config) {
      mysql.configurePlugin(on);
    },
    "env": {
      "db": {
        "host": "localhost",
        "user": "user",
        "password": "password",
        "database": "database"
      }
    }
})

// cypress/support/e2e.js

const mysql = require('cypress-mysql');
mysql.addCommands();

测试

const sql = 'UPDATE "main_backendless.Developer" SET "developerStatusId" = "1" WHERE ("email" = "testuser@example.com")'

cy.query(sql).then(res => {
  expect(res.affectedRows).to.equal(1) 
});

Answer 2

如果你想使用任务来调用mySql库，你必须从任务中返回一个Promise。

这是因为 mysql 调用是异步的，Cypress 知道等待它们的唯一方法是获取从代码返回的承诺。

赛普拉斯.config.js

const { defineConfig } = require("cypress")
const mysql2 = require('mysql2')

const connection = mysql2.createConnection({
  host: '127.0.0.1:3306',
  user: 'root',
  password: 'rootpassword',
  database: 'local1'
})

module.exports = defineConfig({
  e2e: {
    setupNodeEvents(on, config) {
      on('task', {
        mySql: (sql) => {
          return new Promise((resolve, reject) => { 
            connection.query(sql, (error, results) => {
              if (error) {
                reject(error)
              } else {
                resolve(results.affectedRows)
              })
            })
          })
        }
      })
    },
})

it('tests with mysql', () => {
  cy.task('mySql', 'sql staement here')
    .then(result => {
      expect(result).to.equal(1);
    })
})

使用 Promise 包装器

或者，mysql2提供一个可以简化代码的承诺包装器：

const { defineConfig } = require("cypress")
const mysql = require('mysql2/promise')          // different import here

const connection = mysql2.createConnection({
  host: '127.0.0.1:3306',
  user: 'root',
  password: 'rootpassword',
  database: 'local1'
})

module.exports = defineConfig({
  e2e: {
    setupNodeEvents(on, config) {
      on('task', {
        mySql: async (sql) => {                         // async here
          const result = await connection.execute(sql)  // await here
          return result;
        }
      })
    },
})