can now also merge resources and do a symmetric diff.

cmd/yamltool/merge.go

@@ -4,19 +4,50 @@ import (
 	"github.com/goccy/go-yaml"
 	"github.com/spf13/cobra"
 	"os"
+	"reflect"
 )
 
+type MyMap yaml.MapSlice
+
+func (m *MyMap) Set(key any, value any) {
+	for i := range len(*m) {
+		if (*m)[i].Key == key {
+			(*m)[i].Value = value
+			return
+		}
+	}
+	*m = append(*m, yaml.MapItem{Key: key, Value: value})
+}
+
+func (m MyMap) Get(key any) any {
+	for _, item := range m {
+		if item.Key == key {
+			return item.Value
+		}
+	}
+	return nil
+}
+
 func mergeMap(yaml1 yaml.MapSlice, yaml2 yaml.MapSlice) yaml.MapSlice {
-	res := yaml1
+	res := MyMap(yaml1)
 
-	//for key, item := range yaml2 {
-	//	switch {
-	//	case res.ToMap()[key] != nil &&  type
-	//
-	//	}
-	//}
-
-	return res
+	for _, item := range yaml2 {
+		initialValue := res.Get(item.Key)
+		value := item.Value
+		switch {
+		case initialValue != nil:
+			if reflect.TypeOf(initialValue) == reflect.TypeOf(yaml.MapSlice{}) &&
+				reflect.TypeOf(value) == reflect.TypeOf(yaml.MapSlice{}) {
+				mergedMap := mergeMap(initialValue.(yaml.MapSlice), value.(yaml.MapSlice))
+				res.Set(item.Key, mergedMap)
+			} else {
+				res.Set(item.Key, item.Value)
+			}
+		default:
+			res.Set(item.Key, item.Value)
+		}
+	}
+	return yaml.MapSlice(res)
 }
 
 func merge(cmd *cobra.Command, args []string) error {

cmd/yamltool/yamltool.go

@@ -57,7 +57,7 @@ Shows the additions and modifications in <file2> compared to <file1>`,
 	}
 	cmd.AddCommand(merge)
 
-	cmd.PersistentFlags().IntVarP(&VERBOSITY, "array-output-level",
+	diff.PersistentFlags().IntVarP(&VERBOSITY, "array-output-level",
 		"v", 3, `Array output level: ,
 	0: no output, only exit status,
 	1: only show changed/added values,