https://github.com/niraj-khatiwada/node-jest

Testing in Node.js using Jest
https://github.com/niraj-khatiwada/node-jest

Last synced: about 1 month ago
JSON representation

Testing in Node.js using Jest

• Host: GitHub
• URL: https://github.com/niraj-khatiwada/node-jest
• Owner: niraj-khatiwada
• Created: 2023-10-18T07:07:02.000Z (about 1 year ago)
• Default Branch: main
• Last Pushed: 2023-10-25T15:19:52.000Z (about 1 year ago)
• Last Synced: 2023-10-26T13:35:33.820Z (about 1 year ago)
• Language: TypeScript
• Size: 113 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# AAA principle:

- arrange

- act

- assert

# Test Doubles

### Stubs:

- In stubs, you expect a pre-defined output. for eg: success, failure, exception, etc.

- Is the return type correct based on the parameters passed?

### Fakes:

- Fakes are the closest thing that a testing environment when compared to real feature

- For eg: If you want to connect to Google services, instead of connecting to Google in tests, you create a fake http server that mimics as Google server.

- Or you create a fake database implementation that mimics the actual database. Maybe use a in memory SQLite database as fake db.

- Fakes causes limitation where even if you provide very simple implementation not covering all aspect of tests, the test coverage might say 100%. That is solved by mocks.

### Mocks:

- When you want to mock the implementation of a function or a method

- Was the function called correctly? How many times it was called?

- Are the parameters correct?

- Mocks usually do not test the return values. Those are done using stubs.

### Spies:

- Similar to mocks but usually used to mock the methods of an object

# TDD: Test Driven Development

- Chicago vs London

### Chicago

- A unit = collection of pieces working together to make a feature.

- Tests from a broader view

- Little use of mocks

### London

- A unit = a class

- heavy usage of mocks. Mocks all of the dependencies