Jest 테스트코드 Describe vs It

Jest 테스트코드 Describe Vs It¶

제목: What is the difference between describe and it in Jest?
질문 날짜: 2022-09-29
태그: jest
관련 글: Making Test Code at Controller layer Making GetByAuther Test Code (Moking).md)Nest js Create 테스트코드

질문 내용¶

https://stackoverflow.com/questions/32055287/what-is-the-difference-between-describe-and-it-in-jest

질문 답변 (해결 방안)¶

describe breaks your test suite into components. Depending on your test strategy, you might have a describe for each function in your class, each module of your plugin, or each user-facing piece of functionality.

You can also nest describes to further subdivide the suite.

it is where you perform individual tests. You should be able to describe each test like a little sentence, such as “it calculates the area when the radius is set”. You shouldn’t be able to subdivide tests further– if you feel like you need to, use describe instead.

describe('Circle class', function() {  
  describe('area is calculated when', function() {  
    it('sets the radius', function() { ... });  
    it('sets the diameter', function() { ... });  
    it('sets the circumference', function() { ... });  
  });  
});  

As the jest docs says, test and it are the same: https://jestjs.io/docs/en/apitestname-fn-timeout

test(name, fn, timeout)
Also under the alias: it(name, fn, timeout)

and describe is just for when you prefer your tests to be organized into groups: https://jestjs.io/docs/en/apidescribename-fn

describe(name, fn)

describe(name, fn) creates a block that groups together several related tests.
For example, if you have a myBeverage object that is supposed to be delicious but not sour, you could test it with:

const myBeverage = {  
  delicious: true,  
  sour: false,  
};  

describe("my beverage", () => {  
  test("is delicious", () => {  
    expect(myBeverage.delicious).toBeTruthy();  
  });  

  test("is not sour", () => {  
    expect(myBeverage.sour).toBeFalsy();  
  });  
});  

This isn’t required - you can write the test blocks directly at the top level. But this can be handy if you prefer your tests to be organized into groups.