pkg/webhook: test Interpreter

In this commit, we introduce unit tests for the `Interpreter` webhook
across `Decoder`, `HTTP`, `Injection`, `Response`, and `Webhook` components.

Signed-off-by: Mohamed Awnallah <[email protected]>

pkg/webhook/interpreter/decode_test.go

@@ -0,0 +1,234 @@
+/*
+Copyright 2024 The Karmada 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 interpreter
+
+import (
+	"fmt"
+	"testing"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime"
+	schema "k8s.io/apimachinery/pkg/runtime/schema"
+
+	configv1alpha1 "github.com/karmada-io/karmada/pkg/apis/config/v1alpha1"
+)
+
+// MyTestPod represents a simplified version of a Kubernetes Pod for testing purposes.
+// It includes basic fields such as API version, kind, and metadata.
+type MyTestPod struct {
+	APIVersion string `json:"apiVersion"`
+	Kind       string `json:"kind"`
+	Metadata   struct {
+		Name string `json:"name"`
+	} `json:"metadata"`
+}
+
+// DeepCopyObject creates a deep copy of the MyTestPod instance.
+// This method is part of the runtime.Object interface and ensures that modifications
+// to the copy do not affect the original object.
+func (p *MyTestPod) DeepCopyObject() runtime.Object {
+	return &MyTestPod{
+		APIVersion: p.APIVersion,
+		Kind:       p.Kind,
+		Metadata:   p.Metadata,
+	}
+}
+
+// GetObjectKind returns the schema.ObjectKind for the MyTestPod instance.
+// This method is part of the runtime.Object interface and provides the API version
+// and kind of the object, which is used for object identification in Kubernetes.
+func (p *MyTestPod) GetObjectKind() schema.ObjectKind {
+	return &metav1.TypeMeta{
+		APIVersion: p.APIVersion,
+		Kind:       p.Kind,
+	}
+}
+
+func TestNewDecoder(t *testing.T) {
+	// Create a dummy runtime.Scheme object.
+	scheme := runtime.NewScheme()
+	decoder := NewDecoder(scheme)
+
+	// Verify that the Decoder object is created correctly.
+	if decoder == nil {
+		t.Errorf("expected decoder to not be nil")
+	}
+}
+
+func TestDecodeRaw_ValidRaw_Success(t *testing.T) {
+	// Define values to be used during the test.
+	const apiVersion = "v1"
+	const kind = "Pod"
+	const name = "test-pod"
+
+	// Prepare the necessary inputs.
+	rawJSON := fmt.Sprintf(`{"apiVersion": "%s", "kind": "%s", "metadata": {"name": "%s"}}`, apiVersion, kind, name)
+	rawObj := runtime.RawExtension{
+		Raw: []byte(rawJSON),
+	}
+	into := &unstructured.Unstructured{}
+
+	// Create a dummy runtime.Scheme object.
+	scheme := runtime.NewScheme()
+	decoder := NewDecoder(scheme)
+
+	// Call DecodeRaw and expect no errors.
+	err := decoder.DecodeRaw(rawObj, into)
+	if err != nil {
+		t.Errorf("DecodeRaw returned an error: %v", err)
+	}
+
+	// Verify the contents of the decoded object.
+	if got := into.GetAPIVersion(); got != apiVersion {
+		t.Errorf("expected API version '%s', got '%s'", apiVersion, got)
+	}
+	if got := into.GetKind(); got != kind {
+		t.Errorf("expected kind '%s', got '%s'", kind, got)
+	}
+	if got := into.GetName(); got != name {
+		t.Errorf("expected name '%s', got '%s'", name, got)
+	}
+}
+
+func TestDecodeRaw_EmptyRaw_Error(t *testing.T) {
+	// Test case for error when RawExtension has no content.
+	rawObj := runtime.RawExtension{
+		Raw: []byte{},
+	}
+	into := &unstructured.Unstructured{}
+
+	// Create a dummy runtime.Scheme object.
+	scheme := runtime.NewScheme()
+	decoder := NewDecoder(scheme)
+
+	// Call DecodeRaw and expect an error.
+	err := decoder.DecodeRaw(rawObj, into)
+	if err == nil {
+		t.Errorf("Expected error but got nil")
+	}
+
+	// Verify the error message.
+	expectedErrorMessage := "there is no content to decode"
+	if err.Error() != expectedErrorMessage {
+		t.Errorf("Expected error message '%s', got '%s'", expectedErrorMessage, err.Error())
+	}
+}
+
+func TestDecodeRaw_IntoNonUnstructuredType_Success(t *testing.T) {
+	// Define values to be used during the test.
+	const apiVersion = "v1"
+	const kind = "Pod"
+	const name = "test-pod"
+
+	// Prepare the necessary inputs.
+	rawJSON := fmt.Sprintf(`{"apiVersion": "%s", "kind": "%s", "metadata": {"name": "%s"}}`, apiVersion, kind, name)
+	rawObj := runtime.RawExtension{
+		Raw: []byte(rawJSON),
+	}
+
+	// Create an instance of the non-unstructured type.
+	into := &MyTestPod{}
+
+	// Create a dummy runtime.Scheme object.
+	scheme := runtime.NewScheme()
+	decoder := NewDecoder(scheme)
+
+	// Call DecodeRaw and expect no errors.
+	err := decoder.DecodeRaw(rawObj, into)
+	if err != nil {
+		t.Errorf("DecodeRaw returned an error: %v", err)
+	}
+
+	// Verify the contents of the decoded object.
+	if got := into.APIVersion; got != apiVersion {
+		t.Errorf("expected API version '%s', got '%s'", apiVersion, got)
+	}
+	if got := into.Kind; got != kind {
+		t.Errorf("expected kind '%s', got '%s'", kind, got)
+	}
+	if got := into.Metadata.Name; got != name {
+		t.Errorf("expected name '%s', got '%s'", name, got)
+	}
+}
+
+func TestDecode_ValidRaw_Success(t *testing.T) {
+	// Define values to be used during the test.
+	const apiVersion = "v1"
+	const kind = "Pod"
+	const name = "test-pod"
+
+	// Prepare the necessary inputs.
+	rawJSON := fmt.Sprintf(`{"apiVersion": "%s", "kind": "%s", "metadata": {"name": "%s"}}`, apiVersion, kind, name)
+	req := Request{
+		ResourceInterpreterRequest: configv1alpha1.ResourceInterpreterRequest{
+			Object: runtime.RawExtension{
+				Raw: []byte(rawJSON),
+			},
+		},
+	}
+	into := &unstructured.Unstructured{}
+
+	// Create a dummy runtime.Scheme object.
+	scheme := runtime.NewScheme()
+	decoder := NewDecoder(scheme)
+
+	// Call Decode and expect no errors.
+	err := decoder.Decode(req, into)
+	if err != nil {
+		t.Errorf("DecodeRaw returned an error: %v", err)
+	}
+
+	// Verify the contents of the decoded object.
+	if got := into.GetAPIVersion(); got != apiVersion {
+		t.Errorf("expected API version '%s', got '%s'", apiVersion, got)
+	}
+	if got := into.GetKind(); got != kind {
+		t.Errorf("expected kind '%s', got '%s'", kind, got)
+	}
+	if got := into.GetName(); got != name {
+		t.Errorf("expected name '%s', got '%s'", name, got)
+	}
+}
+
+func TestDecode_EmptyRaw_Error(t *testing.T) {
+	// Test case for error when Request object has no content.
+	req := Request{
+		ResourceInterpreterRequest: configv1alpha1.ResourceInterpreterRequest{
+			Object: runtime.RawExtension{
+				Raw: []byte{},
+			},
+		},
+	}
+	into := &unstructured.Unstructured{}
+
+	// Create a dummy runtime.Scheme object.
+	scheme := runtime.NewScheme()
+	decoder := NewDecoder(scheme)
+
+	// Call Decode and expect an error.
+	err := decoder.Decode(req, into)
+	if err == nil {
+		t.Errorf("Expected error but got nil")
+	}
+
+	// Verify the error message.
+	expectedErrorMessage := "there is no content to decode"
+	if err.Error() != expectedErrorMessage {
+		t.Errorf("Expected error message '%s', got '%s'", expectedErrorMessage, err.Error())
+	}
+}