Mocking Examples

Currently there are 2 strategies covered in this project:

1. Mocking a module inside the test file using jest.fn().mock or jest.mockImplementation
2. Mocking a module automatically with a __mocks__ folder

Mocking inside a test folder

This is a nice way to mock functions or modules without having to change or add anything to your source code. In the /01_jestFn folder, we have the following scenarios demonstrated:

• /01_jestFn/01_moduleExport demonstrates how to mock a function that is exported as a module
• /01_jestFn/02_moduleFunction demonstrates how to mock a function that is exported as a method on the module
• /01_jestFn/03_moduleExportClass demonstrates how to mock a class that is exported as a module
• /01_jestFn/04_moduleFunctionClass demonstrates how to mock a class that is exported as a method on the module

Mocking automatically by creating mocks inside a __mocks__ folder

This is great if you want modules to be automatically mocked the same way in all your tests. This requires that you make a __mocks__ folder alongside all your modules. Example:

/io
  /db
    __mocks__
      db.js
    db.js
  /ses
    __mocks__
      ses.js
    ses.js
index.js    

We have the following scenarios demonstrated:

• /02_mockFolder/01_moduleExport demonstrates how to mock a function that is exported as a module
• /02_mockFolder/02_moduleFunction demonstrates how to mock a function that is exported as a method on the module
• /02_mockFolder/03_moduleExportClass demonstrates how to mock a class that is exported as a module
• /02_mockFolder/04_moduleFunctionClass demonstrates how to mock a class that is exported as a method on the module