jest-notes

0_jest-notes.md

Ref.

• Jest matching objects in array
• Jest cheetsheet

custom-matcher.js

expect.extend({
  toContainObject(received, argument) {

    const pass = this.equals(received, 
      expect.arrayContaining([
        expect.objectContaining(argument)
      ])
    )

    if (pass) {
      return {
        message: () => (`expected ${this.utils.printReceived(received)} not to contain object ${this.utils.printExpected(argument)}`),
        pass: true
      }
    } else {
      return {
        message: () => (`expected ${this.utils.printReceived(received)} to contain object ${this.utils.printExpected(argument)}`),
        pass: false
      }
    }
  }
})