kubectl: add test coverage for cordon command (kubernetes#129202)

* kubectl: add test coverage for cordon command

Signed-off-by: Omer Aplatony <[email protected]>

* using cmp.Diff

Signed-off-by: Omer Aplatony <[email protected]>

---------

Signed-off-by: Omer Aplatony <[email protected]>

Author: omerap12

staging/src/k8s.io/kubectl/pkg/drain/cordon_test.go

@@ -0,0 +1,147 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+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 drain
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+type newCordonHelperFromRuntimeObjectTestCase struct {
+	name        string
+	nodeObject  runtime.Object
+	expectError bool
+	expected    *CordonHelper
+}
+
+func TestNewCordonHelperFromRuntimeObject(t *testing.T) {
+	tests := []newCordonHelperFromRuntimeObjectTestCase{
+		{
+			name: "valid node object",
+			nodeObject: &corev1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test-node",
+				},
+			},
+			expectError: false,
+			expected: &CordonHelper{
+				node: &corev1.Node{
+					TypeMeta: metav1.TypeMeta{
+						Kind:       "Node",
+						APIVersion: "v1",
+					},
+					ObjectMeta: metav1.ObjectMeta{
+						Name: "test-node",
+					},
+				},
+			},
+		},
+		{
+			name: "invalid object type",
+			nodeObject: &corev1.Pod{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test-pod",
+				},
+			},
+			expectError: true,
+			expected:    nil,
+		},
+	}
+	scheme := runtime.NewScheme()
+	_ = corev1.AddToScheme(scheme)
+	gvk := schema.GroupVersionKind{
+		Group:   "",
+		Version: "v1",
+		Kind:    "Node",
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			helper, err := NewCordonHelperFromRuntimeObject(tt.nodeObject, scheme, gvk)
+			if tt.expectError && err == nil {
+				t.Error("Expected error but got none")
+			}
+			if !tt.expectError && err != nil {
+				t.Errorf("Unexpected error: %v", err)
+			}
+			if !tt.expectError && helper == nil {
+				t.Error("Expected non-nil helper")
+			}
+			if tt.expected != nil && helper != nil {
+				if diff := cmp.Diff(tt.expected.node, helper.node); diff != "" {
+					t.Errorf("Node mismatch (-want +got):\n%s", diff)
+				}
+			}
+		})
+	}
+}
+
+type updateIfRequiredTestCase struct {
+	name          string
+	currentState  bool
+	desiredState  bool
+	expectUpdated bool
+}
+
+func TestUpdateIfRequired(t *testing.T) {
+	tests := []updateIfRequiredTestCase{
+		{
+			name:          "no change required",
+			currentState:  true,
+			desiredState:  true,
+			expectUpdated: false,
+		},
+		{
+			name:          "update required - cordon",
+			currentState:  false,
+			desiredState:  true,
+			expectUpdated: true,
+		},
+		{
+			name:          "update required - uncordon",
+			currentState:  true,
+			desiredState:  false,
+			expectUpdated: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			node := &corev1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test-node",
+				},
+				Spec: corev1.NodeSpec{
+					Unschedulable: tt.currentState,
+				},
+			}
+
+			helper := NewCordonHelper(node)
+			updated := helper.UpdateIfRequired(tt.desiredState)
+			if updated != tt.expectUpdated {
+				t.Errorf("Expected UpdateIfRequired to return %v, got %v", tt.expectUpdated, updated)
+			}
+			if helper.desired != tt.desiredState {
+				t.Errorf("Expected desired state to be %v, got %v", tt.desiredState, helper.desired)
+			}
+		})
+	}
+}