example of a creating a mock controller for you test suite.

mock_controller.go

var _ = Describe("Person", func() {
        var (
                mockFetcher *mock_S3Fetcher.MockS3Fetcher
                ctrl    *gomock.Controller
        )
        BeforeEach(func() {
                ctrl = gomock.NewController(GinkgoT())
        })
        AfterEach(func() {
                ctrl.Finish()
        })