#JEST MOCKS UPDATE#

One downside to fully manual mocks is that they're manual – meaning you have to manually update them any time the module they are mocking changes. If you do not want to use the automatic mock at all, you can export your own functions from the mock file. This is the recommended approach, but is completely optional. The example mock shown here uses jest.createMockFromModule to generate an automatic mock, and overrides its default behavior. jest.mock('path') is required, because core Node modules are not mocked by default. Warning: If we want to mock Node's core modules (e.g.: fs or path), then explicitly calling e.g. For example, to mock a scoped module called create a file at creating the directory accordingly. Scoped modules (also known as scoped packages) can be mocked by creating a file in a directory structure that matches the name of the scoped module. There's no need to explicitly call jest.mock('module_name'). If the module you are mocking is a Node module (e.g.: lodash), the mock should be placed in the _mocks_ directory adjacent to node_modules (unless you configured roots to point to a folder other than the project root) and will be automatically mocked. When we require that module in our tests (meaning we want to use the manual mock instead of the real implementation), explicitly calling jest.mock('./moduleName') is required. Note that the _mocks_ folder is case-sensitive, so naming the directory _MOCKS_ will break on some systems. For example, to mock a module called user in the models directory, create a file called user.js and put it in the models/_mocks_ directory. Manual mocks are defined by writing a module in a _mocks_/ subdirectory immediately adjacent to the module. This ensures your tests will be fast and not flaky. For example, instead of accessing a remote resource like a website or a database, you might want to create a manual mock that allows you to use fake data. Manual mocks are used to stub out functionality with mock data.

Jest mocks