func TestResourceProvider_diff_error(t *testing.T) { p := new(terraform.MockResourceProvider) client, server := testClientServer(t) name, err := Register(server, p) if err != nil { t.Fatalf("err: %s", err) } provider := &ResourceProvider{Client: client, Name: name} p.DiffReturnError = errors.New("foo") // Diff info := &terraform.InstanceInfo{} state := &terraform.InstanceState{} config := &terraform.ResourceConfig{ Raw: map[string]interface{}{"foo": "bar"}, } diff, err := provider.Diff(info, state, config) if !p.DiffCalled { t.Fatal("diff should be called") } if !reflect.DeepEqual(p.DiffDesired, config) { t.Fatalf("bad: %#v", p.DiffDesired) } if err == nil { t.Fatal("should have error") } if diff != nil { t.Fatal("should not have diff") } }