Add support for JSON patch in fake client

Kubernetes-commit: a363b153851326ece7f81f4c1ae0a1ab8700a209

dynamic/fake/simple.go

@@ -331,25 +331,26 @@ func (c *dynamicResourceClient) Watch(opts metav1.ListOptions) (watch.Interface,
 	panic("math broke")
 }
 
+// TODO: opts are currently ignored.
 func (c *dynamicResourceClient) Patch(name string, pt types.PatchType, data []byte, opts metav1.UpdateOptions, subresources ...string) (*unstructured.Unstructured, error) {
 	var uncastRet runtime.Object
 	var err error
 	switch {
 	case len(c.namespace) == 0 && len(subresources) == 0:
 		uncastRet, err = c.client.Fake.
-			Invokes(testing.NewRootPatchAction(c.resource, name, data), &metav1.Status{Status: "dynamic patch fail"})
+			Invokes(testing.NewRootPatchAction(c.resource, name, pt, data), &metav1.Status{Status: "dynamic patch fail"})
 
 	case len(c.namespace) == 0 && len(subresources) > 0:
 		uncastRet, err = c.client.Fake.
-			Invokes(testing.NewRootPatchSubresourceAction(c.resource, name, data, subresources...), &metav1.Status{Status: "dynamic patch fail"})
+			Invokes(testing.NewRootPatchSubresourceAction(c.resource, name, pt, data, subresources...), &metav1.Status{Status: "dynamic patch fail"})
 
 	case len(c.namespace) > 0 && len(subresources) == 0:
 		uncastRet, err = c.client.Fake.
-			Invokes(testing.NewPatchAction(c.resource, c.namespace, name, data), &metav1.Status{Status: "dynamic patch fail"})
+			Invokes(testing.NewPatchAction(c.resource, c.namespace, name, pt, data), &metav1.Status{Status: "dynamic patch fail"})
 
 	case len(c.namespace) > 0 && len(subresources) > 0:
 		uncastRet, err = c.client.Fake.
-			Invokes(testing.NewPatchSubresourceAction(c.resource, c.namespace, name, data, subresources...), &metav1.Status{Status: "dynamic patch fail"})
+			Invokes(testing.NewPatchSubresourceAction(c.resource, c.namespace, name, pt, data, subresources...), &metav1.Status{Status: "dynamic patch fail"})
 
 	}
 

dynamic/fake/simple_test.go

@@ -17,16 +17,28 @@ limitations under the License.
 package fake
 
 import (
+	"fmt"
 	"testing"
 
 	"k8s.io/apimachinery/pkg/api/equality"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/diff"
 )
 
+const (
+	testGroup      = "testgroup"
+	testVersion    = "testversion"
+	testResource   = "testkinds"
+	testNamespace  = "testns"
+	testName       = "testname"
+	testKind       = "TestKind"
+	testAPIVersion = "testgroup/testversion"
+)
+
 func newUnstructured(apiVersion, kind, namespace, name string) *unstructured.Unstructured {
 	return &unstructured.Unstructured{
 		Object: map[string]interface{}{
@@ -40,6 +52,12 @@ func newUnstructured(apiVersion, kind, namespace, name string) *unstructured.Uns
 	}
 }
 
+func newUnstructuredWithSpec(spec map[string]interface{}) *unstructured.Unstructured {
+	u := newUnstructured(testAPIVersion, testKind, testNamespace, testName)
+	u.Object["spec"] = spec
+	return u
+}
+
 func TestList(t *testing.T) {
 	scheme := runtime.NewScheme()
 
@@ -64,3 +82,116 @@ func TestList(t *testing.T) {
 		t.Fatal(diff.ObjectGoPrintDiff(expected, listFirst.Items))
 	}
 }
+
+type patchTestCase struct {
+	name                  string
+	object                runtime.Object
+	patchType             types.PatchType
+	patchBytes            []byte
+	wantErrMsg            string
+	expectedPatchedObject runtime.Object
+}
+
+func (tc *patchTestCase) runner(t *testing.T) {
+	client := NewSimpleDynamicClient(runtime.NewScheme(), tc.object)
+	resourceInterface := client.Resource(schema.GroupVersionResource{Group: testGroup, Version: testVersion, Resource: testResource}).Namespace(testNamespace)
+
+	got, recErr := resourceInterface.Patch(testName, tc.patchType, tc.patchBytes, metav1.UpdateOptions{})
+
+	if err := tc.verifyErr(recErr); err != nil {
+		t.Error(err)
+	}
+
+	if err := tc.verifyResult(got); err != nil {
+		t.Error(err)
+	}
+
+}
+
+// verifyErr verifies that the given error returned from Patch is the error
+// expected by the test case.
+func (tc *patchTestCase) verifyErr(err error) error {
+	if tc.wantErrMsg != "" && err == nil {
+		return fmt.Errorf("want error, got nil")
+	}
+
+	if tc.wantErrMsg == "" && err != nil {
+		return fmt.Errorf("want no error, got %v", err)
+	}
+
+	if err != nil {
+		if want, got := tc.wantErrMsg, err.Error(); want != got {
+			return fmt.Errorf("incorrect error: want: %q got: %q", want, got)
+		}
+	}
+	return nil
+}
+
+func (tc *patchTestCase) verifyResult(result *unstructured.Unstructured) error {
+	if tc.expectedPatchedObject == nil && result == nil {
+		return nil
+	}
+	if !equality.Semantic.DeepEqual(result, tc.expectedPatchedObject) {
+		return fmt.Errorf("unexpected diff in received object: %s", diff.ObjectGoPrintDiff(tc.expectedPatchedObject, result))
+	}
+	return nil
+}
+
+func TestPatch(t *testing.T) {
+	testCases := []patchTestCase{
+		{
+			name:       "jsonpatch fails with merge type",
+			object:     newUnstructuredWithSpec(map[string]interface{}{"foo": "bar"}),
+			patchType:  types.StrategicMergePatchType,
+			patchBytes: []byte(`[]`),
+			wantErrMsg: "invalid JSON document",
+		}, {
+			name:      "jsonpatch works with empty patch",
+			object:    newUnstructuredWithSpec(map[string]interface{}{"foo": "bar"}),
+			patchType: types.JSONPatchType,
+			// No-op
+			patchBytes:            []byte(`[]`),
+			expectedPatchedObject: newUnstructuredWithSpec(map[string]interface{}{"foo": "bar"}),
+		}, {
+			name:      "jsonpatch works with simple change patch",
+			object:    newUnstructuredWithSpec(map[string]interface{}{"foo": "bar"}),
+			patchType: types.JSONPatchType,
+			// change spec.foo from bar to foobar
+			patchBytes:            []byte(`[{"op": "replace", "path": "/spec/foo", "value": "foobar"}]`),
+			expectedPatchedObject: newUnstructuredWithSpec(map[string]interface{}{"foo": "foobar"}),
+		}, {
+			name:      "jsonpatch works with simple addition",
+			object:    newUnstructuredWithSpec(map[string]interface{}{"foo": "bar"}),
+			patchType: types.JSONPatchType,
+			// add spec.newvalue = dummy
+			patchBytes:            []byte(`[{"op": "add", "path": "/spec/newvalue", "value": "dummy"}]`),
+			expectedPatchedObject: newUnstructuredWithSpec(map[string]interface{}{"foo": "bar", "newvalue": "dummy"}),
+		}, {
+			name:      "jsonpatch works with simple deletion",
+			object:    newUnstructuredWithSpec(map[string]interface{}{"foo": "bar", "toremove": "shouldnotbehere"}),
+			patchType: types.JSONPatchType,
+			// remove spec.newvalue = dummy
+			patchBytes:            []byte(`[{"op": "remove", "path": "/spec/toremove"}]`),
+			expectedPatchedObject: newUnstructuredWithSpec(map[string]interface{}{"foo": "bar"}),
+		}, {
+			name:      "strategic merge patch fails with JSONPatch",
+			object:    newUnstructuredWithSpec(map[string]interface{}{"foo": "bar"}),
+			patchType: types.StrategicMergePatchType,
+			// add spec.newvalue = dummy
+			patchBytes: []byte(`[{"op": "add", "path": "/spec/newvalue", "value": "dummy"}]`),
+			wantErrMsg: "invalid JSON document",
+		}, {
+			name:       "merge patch fails as unsupported",
+			object:     newUnstructured(testAPIVersion, testKind, testNamespace, testName),
+			patchType:  types.MergePatchType,
+			patchBytes: []byte(`{}`),
+			wantErrMsg: "PatchType is not supported",
+		},
+		// TODO: Add tests for strategic merge using v1.Pod for example to ensure the test cases
+		// demonstrate expected use cases.
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, tc.runner)
+	}
+}