implement some unit tests

pkg/customresourcestate/generate/markers/helper_test.go

@@ -0,0 +1,123 @@
+/*
+Copyright 2023 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+package markers
+
+import (
+	"reflect"
+	"testing"
+
+	"k8s.io/kube-state-metrics/v2/pkg/customresourcestate"
+)
+
+func Test_jsonPath_Parse(t *testing.T) {
+	tests := []struct {
+		name    string
+		j       jsonPath
+		want    []string
+		wantErr bool
+	}{
+		{
+			name:    "empty input",
+			j:       "",
+			want:    []string{},
+			wantErr: false,
+		},
+		{
+			name:    "dot input",
+			j:       ".",
+			want:    []string{""},
+			wantErr: false,
+		},
+		{
+			name:    "some path input",
+			j:       ".foo.bar",
+			want:    []string{"foo", "bar"},
+			wantErr: false,
+		},
+		{
+			name:    "invalid character ,",
+			j:       ".foo,.bar",
+			wantErr: true,
+		},
+		{
+			name:    "invalid closure",
+			j:       "{.foo}",
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := tt.j.Parse()
+			if (err != nil) != tt.wantErr {
+				t.Errorf("jsonPath.Parse() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("jsonPath.Parse() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_newMetricMeta(t *testing.T) {
+	tests := []struct {
+		name               string
+		basePath           []string
+		j                  jsonPath
+		jsonLabelsFromPath map[string]jsonPath
+		want               customresourcestate.MetricMeta
+	}{
+		{
+			name:               "with basePath and jsonpath, without jsonLabelsFromPath",
+			basePath:           []string{"foo"},
+			j:                  jsonPath(".bar"),
+			jsonLabelsFromPath: map[string]jsonPath{},
+			want: customresourcestate.MetricMeta{
+				Path:           []string{"foo", "bar"},
+				LabelsFromPath: map[string][]string{},
+			},
+		},
+		{
+			name:               "with basePath, jsonpath and jsonLabelsFromPath",
+			basePath:           []string{"foo"},
+			j:                  jsonPath(".bar"),
+			jsonLabelsFromPath: map[string]jsonPath{"some": ".label.from.path"},
+			want: customresourcestate.MetricMeta{
+				Path: []string{"foo", "bar"},
+				LabelsFromPath: map[string][]string{
+					"some": {"label", "from", "path"},
+				},
+			},
+		},
+		{
+			name:               "no basePath, jsonpath and jsonLabelsFromPath",
+			basePath:           []string{},
+			j:                  jsonPath(""),
+			jsonLabelsFromPath: map[string]jsonPath{},
+			want: customresourcestate.MetricMeta{
+				Path:           []string{},
+				LabelsFromPath: map[string][]string{},
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := newMetricMeta(tt.basePath, tt.j, tt.jsonLabelsFromPath); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("newMetricMeta() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

pkg/customresourcestate/generate/markers/labelfrompath.go

@@ -16,6 +16,7 @@ limitations under the License.
 package markers
 
 import (
+	"errors"
 	"fmt"
 
 	"sigs.k8s.io/controller-tools/pkg/markers"
@@ -59,14 +60,19 @@ func (labelFromPathMarker) Help() *markers.DefinitionHelp {
 }
 
 func (n labelFromPathMarker) ApplyToResource(resource *customresourcestate.Resource) error {
-	if resource.LabelsFromPath == nil {
-		resource.LabelsFromPath = map[string][]string{}
+	if resource == nil {
+		return errors.New("expected resource to not be nil")
 	}
+
 	jsonPathElems, err := n.JSONPath.Parse()
 	if err != nil {
 		return err
 	}
 
+	if resource.LabelsFromPath == nil {
+		resource.LabelsFromPath = map[string][]string{}
+	}
+
 	if jsonPath, labelExists := resource.LabelsFromPath[n.Name]; labelExists {
 		if len(jsonPathElems) != len(jsonPath) {
 			return fmt.Errorf("duplicate definition for label %q", n.Name)

pkg/customresourcestate/generate/markers/labelfrompath_test.go

@@ -0,0 +1,132 @@
+/*
+Copyright 2023 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+package markers
+
+import (
+	"reflect"
+	"testing"
+
+	"k8s.io/kube-state-metrics/v2/pkg/customresourcestate"
+)
+
+func Test_labelFromPathMarker_ApplyToResource(t *testing.T) {
+	type fields struct {
+		Name     string
+		JSONPath jsonPath
+	}
+	tests := []struct {
+		name         string
+		fields       fields
+		resource     *customresourcestate.Resource
+		wantResource *customresourcestate.Resource
+		wantErr      bool
+	}{
+		{
+			name: "happy path",
+			fields: fields{
+				Name:     "foo",
+				JSONPath: ".bar",
+			},
+			resource: &customresourcestate.Resource{},
+			wantResource: &customresourcestate.Resource{
+				Labels: customresourcestate.Labels{
+					LabelsFromPath: map[string][]string{
+						"foo": {"bar"},
+					},
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name: "label already exists with same path length",
+			fields: fields{
+				Name:     "foo",
+				JSONPath: ".bar",
+			},
+			resource: &customresourcestate.Resource{
+				Labels: customresourcestate.Labels{
+					LabelsFromPath: map[string][]string{
+						"foo": {"other"},
+					},
+				},
+			},
+			wantResource: &customresourcestate.Resource{
+				Labels: customresourcestate.Labels{
+					LabelsFromPath: map[string][]string{
+						"foo": {"other"},
+					},
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "label already exists with different path length",
+			fields: fields{
+				Name:     "foo",
+				JSONPath: ".bar",
+			},
+			resource: &customresourcestate.Resource{
+				Labels: customresourcestate.Labels{
+					LabelsFromPath: map[string][]string{
+						"foo": {"other", "path"},
+					},
+				},
+			},
+			wantResource: &customresourcestate.Resource{
+				Labels: customresourcestate.Labels{
+					LabelsFromPath: map[string][]string{
+						"foo": {"other", "path"},
+					},
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "invalid json path",
+			fields: fields{
+				Name:     "foo",
+				JSONPath: "{.bar}",
+			},
+			resource:     &customresourcestate.Resource{},
+			wantResource: &customresourcestate.Resource{},
+			wantErr:      true,
+		},
+		{
+			name: "nil resource",
+			fields: fields{
+				Name:     "foo",
+				JSONPath: "{.bar}",
+			},
+			resource: nil,
+			wantErr:  true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			n := labelFromPathMarker{
+				Name:     tt.fields.Name,
+				JSONPath: tt.fields.JSONPath,
+			}
+			if err := n.ApplyToResource(tt.resource); (err != nil) != tt.wantErr {
+				t.Errorf("labelFromPathMarker.ApplyToResource() error = %v, wantErr %v", err, tt.wantErr)
+			}
+			if !reflect.DeepEqual(tt.resource, tt.wantResource) {
+				t.Errorf("labelFromPathMarker.ApplyToResource() = %v, want %v", tt.resource, tt.wantResource)
+			}
+
+		})
+	}
+}