fix: handle null input in deleteStatusAndTidyMetadata

- Return nil without panic when JSON input is null
- Safely handle missing metadata field with type assertion
- Add test case for null JSON input

Signed-off-by: yxxhero <aiopsclub@163.com>

Author: yxxhero

manifest/generate.go

@@ -248,6 +248,9 @@ func cleanMetadataForPatch(data []byte) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
+	if objMap == nil {
+		return []byte("null"), nil
+	}
 	return json.Marshal(objMap)
 }
 

manifest/util.go

@@ -13,18 +13,23 @@ func deleteStatusAndTidyMetadata(obj []byte) (map[string]interface{}, error) {
 		return nil, fmt.Errorf("could not unmarshal byte sequence: %w", err)
 	}
 
+	if objectMap == nil {
+		return nil, nil
+	}
+
 	delete(objectMap, "status")
 
-	metadata := objectMap["metadata"].(map[string]interface{})
+	metadata, ok := objectMap["metadata"].(map[string]interface{})
+	if !ok {
+		return objectMap, nil
+	}
 
 	delete(metadata, "managedFields")
 	delete(metadata, "generation")
 	delete(metadata, "creationTimestamp")
 	delete(metadata, "resourceVersion")
 	delete(metadata, "uid")
 
-	// See the below for the goal of this metadata tidy logic.
-	// https://github.com/databus23/helm-diff/issues/326#issuecomment-1008253274
 	if a := metadata["annotations"]; a != nil {
 		annotations := a.(map[string]interface{})
 		delete(annotations, "meta.helm.sh/release-name")

manifest/util_test.go

@@ -19,6 +19,12 @@ func Test_deleteStatusAndTidyMetadata(t *testing.T) {
 			want:    nil,
 			wantErr: true,
 		},
+		{
+			name:    "null json",
+			obj:     []byte("null"),
+			want:    nil,
+			wantErr: false,
+		},
 		{
 			name: "valid json",
 			obj: []byte(`