chore: add more cli utils unit tests (#8243)

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>

cmd/cli/kubectl-kyverno/testdata/values/bad-format.yaml

@@ -0,0 +1,6 @@
+foo: bar
+
+namespaceSelector:
+  - name: test1
+    labels:
+      foo.com/managed-state: managed

cmd/cli/kubectl-kyverno/testdata/values/valid.yaml

@@ -0,0 +1,14 @@
+policies:
+  - name: limit-configmap-for-sa
+    resources:
+      - name: any-configmap-name-good
+        values:
+          request.operation: UPDATE
+      - name: any-configmap-name-bad
+        values:
+          request.operation: UPDATE
+
+namespaceSelector:
+  - name: test1
+    labels:
+      foo.com/managed-state: managed

cmd/cli/kubectl-kyverno/utils/values/load_test.go

@@ -0,0 +1,123 @@
+package values
+
+import (
+	"os"
+	"reflect"
+	"testing"
+
+	"github.com/go-git/go-billy/v5"
+	"github.com/kyverno/kyverno/cmd/cli/kubectl-kyverno/test/api"
+)
+
+func Test_readFile(t *testing.T) {
+	mustReadFile := func(path string) []byte {
+		t.Helper()
+		data, err := os.ReadFile(path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return data
+	}
+	tests := []struct {
+		name     string
+		f        billy.Filesystem
+		filepath string
+		want     []byte
+		wantErr  bool
+	}{{
+		name:     "empty",
+		filepath: "",
+		want:     nil,
+		wantErr:  true,
+	}, {
+		name:     "does not exist",
+		filepath: "../../testdata/values/doesnotexist",
+		want:     nil,
+		wantErr:  true,
+	}, {
+		name:     "bad format",
+		filepath: "../../testdata/values/bad-format.yaml",
+		want:     mustReadFile("../../testdata/values/bad-format.yaml"),
+		wantErr:  false,
+	}, {
+		name:     "valid",
+		filepath: "../../testdata/values/valid.yaml",
+		want:     mustReadFile("../../testdata/values/valid.yaml"),
+		wantErr:  false,
+	}}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := readFile(tt.f, tt.filepath)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("readFile() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("readFile() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestLoad(t *testing.T) {
+	tests := []struct {
+		name     string
+		f        billy.Filesystem
+		filepath string
+		want     *api.Values
+		wantErr  bool
+	}{{
+		name:     "empty",
+		filepath: "",
+		want:     nil,
+		wantErr:  true,
+	}, {
+		name:     "does not exist",
+		filepath: "../../testdata/values/doesnotexist",
+		want:     nil,
+		wantErr:  true,
+	}, {
+		name:     "bad format",
+		filepath: "../../testdata/values/bad-format.yaml",
+		want:     nil,
+		wantErr:  true,
+	}, {
+		name:     "valid",
+		filepath: "../../testdata/values/valid.yaml",
+		want: &api.Values{
+			NamespaceSelectors: []api.NamespaceSelector{{
+				Name: "test1",
+				Labels: map[string]string{
+					"foo.com/managed-state": "managed",
+				},
+			}},
+			Policies: []api.Policy{{
+				Name: "limit-configmap-for-sa",
+				Resources: []api.Resource{{
+					Name: "any-configmap-name-good",
+					Values: map[string]interface{}{
+						"request.operation": "UPDATE",
+					},
+				}, {
+					Name: "any-configmap-name-bad",
+					Values: map[string]interface{}{
+						"request.operation": "UPDATE",
+					},
+				}},
+			}},
+		},
+		wantErr: false,
+	}}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := Load(tt.f, tt.filepath)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Load() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("Load() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}