Module testify is a set of packages that provide many tools for testifying that your code will behave as you intend. Testify contains the following packages: The github.com/stretchr/testify/assert package provides a comprehensive set of assertion functions that tie in to the Go testing system. The github.com/stretchr/testify/require package provides the same assertions but as fatal checks. A golangci-lint compatible linter for testify is available called testifylint.