How to Use mockery for Generating Mocks in Go

Use the mockery CLI tool to generate mock implementations for your Go interfaces by specifying the interface name and output directory. Run the following command to generate a mock for an interface named ExampleInterface in the current package:

mockery --name=ExampleInterface --output=./mocks --outpkg=mocks --case=snake

This command creates a file mocks/mock_example_interface.go containing a struct that embeds mock.Mock and implements the interface methods using m.Called() to record expectations and return values.

Mockery is a tool that automatically writes fake versions of your code's interfaces so you can test your software without needing real databases or external services. Think of it like a stand-in actor who follows a script you wrote, allowing you to rehearse your main scene without needing the whole cast. You use it whenever you need to isolate a piece of code to test it quickly and reliably.