Mocking for go exec package using monkey patching
exec.Command and exec.CommandContext is frequently used and need mock for testing purpose. Using monkey-patching to replace the function and return modified Command struct.
Reference:
- https://github.com/bouk/monkey
- https://golang.org/src/os/exec/exec.go
- https://www.joeshaw.org/testing-with-os-exec-and-testmain/
func TestFunction(t *testing.T){
mock := execmock.New()
defer mock.Close()
mock.CommandContext("mkdir").Args("some-folder").Return(errors.New("some-error"))
err = exec.Command("mkdir", "some-folder").Run() // return "some-error"
// ....
}