1. Jest works well with other testing libraries like
Answer: all of the options
2. Jest is used to test _.
Answer: Java script
3. Jest is a JavaScript unit testing framework.
Answer: True
4. How to install Jest using npm?
Answer: npm install --save-dev jest
5. The below test will pass.
Answer: False
6. You can check strings against regular expressions with ______________ .
Answer: toMatch
7. Jest uses ________ and ________ matchers to test a value is with exact equality
Answer: ToBe , toEqual
8. The number can be compared using
Answer: all of the options
9. To create a mock function, we use jest.fn().
Answer: True
10. ______________ resets all information stored in the mockFn.mock.calls and mockFn.mock.instances arrays.
Answer: mockClear()
11. .mock is a property of mock function, the place where all information about how the function has been called is kept.
Answer: True
12. Jest supports ______________ for Isolating functionality into small, testable units under test.
Answer: Mock fn
13. The Asynchronous code will move on to another task before it finishes.
Answer: True
14. When you execute ______________ Code, it will move on to another task before it finishes.
Answer: asyn
15. Jest will wait until the ______________ callback is called before finishing the test.
Answer: done
16. ______________ is useful when you want to mock functions in certain test cases and restore the original implementation in others.
Answer: mockRestore()
17. ______________ resets all information stored in the mock, including any inital implementation given.
Answer: mockReset()
18. To test a particular function which throws an error when it's called, you can use toThrow.
Answer: True
19. Code coverage tests that how much code is covered under tests
Answer: True
20. ______________ is useful when you want to completely restore a mock back to its initial state.
Answer: mockreset
21. The Synchronous Code will move on to another task before it finishes.
Answer: False
22. What is the command to install Jest and the babel-jest ?
a. $ npm install –dev-save jest babel-jest
b. $ npm install jest --save-dev babel-jest
c. $ npm install --save-dev jest babel-jest
d. $ npm install -save-dev jest babel-jest
Answer:- $ npm install jest --save-dev babel-jest
23. ______________ returns the value only once when mock function is called.
a. mockReturnValue(value)
b. mockReturnOnce(value)
c. mockReturnValueOnce(value)
d. None of the options
Correct answer is:- mockReturnValue(value)
24. How to install Jest using yarn?
Answer: - yarn add --dev jest
25. ______________ is an array that records all the object instances that have been instantiated from the mock function using new.
Answer:- mock.instances
26. Which method is useful to clean up a mock's usage data between two assertions.
Answer:- mockClear()
27. mockRestore() removes the mock and restores the initial implementation
Answer :- True
28. How to install Jest using npm?
a. npm install jest --save-dev
b. npm install --save-dev jest
c. npm add –save-dev jest
d. all the options
Correct answer is: - all the options
