review fixes

docs/cli-arguments.md

@@ -31,7 +31,7 @@ Usage:
 
 Available Commands:
   completion  Generate completion script for kube-state-metrics.
-  generate    Generate custom resource metrics configuration from go-code markers.
+  generate    Generate custom resource metrics configuration from go-code markers (experimental).
   help        Help about any command
   version     Print version information.
 

pkg/customresourcestate/generate/cmd.go

@@ -44,7 +44,7 @@ var (
 // GenerateCommand runs the kube-state-metrics custom resource config generator.
 var GenerateCommand = &cobra.Command{
 	Use:                   "generate [flags] /path/to/package [/path/to/package]",
-	Short:                 "Generate custom resource metrics configuration from go-code markers.",
+	Short:                 "Generate custom resource metrics configuration from go-code markers (experimental).",
 	DisableFlagsInUseLine: true,
 	Args:                  cobra.MinimumNArgs(1),
 	RunE: func(cmd *cobra.Command, args []string) error {

pkg/customresourcestate/generate/generator/generate_integration_test.go

@@ -22,6 +22,7 @@ import (
 	"path"
 	"testing"
 
+	"github.com/google/go-cmp/cmp"
 	"sigs.k8s.io/controller-tools/pkg/genall"
 	"sigs.k8s.io/controller-tools/pkg/loader"
 	"sigs.k8s.io/controller-tools/pkg/markers"
@@ -73,10 +74,15 @@ func Test_Generate(t *testing.T) {
 		t.Error(err)
 	}
 
-	if string(expectedFile) != output {
+	diff := cmp.Diff(string(expectedFile), output)
+	if diff != "" {
 		t.Log("output:")
 		t.Log(output)
-		t.Error("Expected output to match file testdata/foo-config.yaml")
+		t.Log("diff:")
+		t.Log(diff)
+		t.Log("Expected output to match file `testdata/foo-config.yaml` but it does not.")
+		t.Log("If the change is intended, use `go generate ./pkg/customresourcestate/generate/generator/testdata` to regenerate the `testdata/foo-config.yaml` file.")
+		t.Error("Detected a diff between the output of the integration test and the file `testdata/foo-config.yaml`.")
 	}
 }
 

pkg/customresourcestate/generate/generator/testdata/foo_types.go

@@ -14,6 +14,11 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// Changes to this file may require to regenerate the `foo-config.yaml`. Otherwise the
+// tests in ../generate_integration_test.go may fail.
+// The below marker can be used to regenerate the `foo-config.yaml` file by running
+// the following command:
+// $ go generate ./pkg/customresourcestate/generate/generator/testdata
 //go:generate sh -c "go run ../../../../../ generate ./... > foo-config.yaml"
 
 // +groupName=bar.example.com

pkg/customresourcestate/generate/markers/gvk.go

@@ -55,6 +55,8 @@ func (gvkMarker) Help() *markers.DefinitionHelp {
 }
 
 func (n gvkMarker) ApplyToResource(resource *customresourcestate.Resource) error {
-	resource.MetricNamePrefix = &n.NamePrefix
+	if n.NamePrefix != "" {
+		resource.MetricNamePrefix = &n.NamePrefix
+	}
 	return nil
 }