package packer type TestBuilder struct { prepareCalled bool prepareConfig interface{} runCalled bool runHook Hook runUi Ui } func (tb *TestBuilder) Prepare(config interface{}) error { tb.prepareCalled = true tb.prepareConfig = config return nil } func (tb *TestBuilder) Run(ui Ui, h Hook) Artifact { tb.runCalled = true tb.runHook = h tb.runUi = ui return nil }