chore: remove mitchellh/copystructure dependency

Author: TerryHowe

copystructure.go

@@ -0,0 +1,104 @@
+package sprig
+
+import (
+	"fmt"
+	"reflect"
+)
+
+// Copy performs a deep copy of the given interface{}.
+// This implementation handles the specific use cases needed by Helm.
+func Copy(src interface{}) (interface{}, error) {
+	if src == nil {
+		return make(map[string]interface{}), nil
+	}
+	return copyValue(reflect.ValueOf(src))
+}
+
+// copyValue handles copying using reflection for non-map types
+func copyValue(original reflect.Value) (interface{}, error) {
+	switch original.Kind() {
+	case reflect.Bool, reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32,
+		reflect.Int64, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32,
+		reflect.Uint64, reflect.Uintptr, reflect.Float32, reflect.Float64,
+		reflect.Complex64, reflect.Complex128, reflect.String, reflect.Array:
+		return original.Interface(), nil
+
+	case reflect.Interface:
+		if original.IsNil() {
+			return original.Interface(), nil
+		}
+		return copyValue(original.Elem())
+
+	case reflect.Map:
+		if original.IsNil() {
+			return original.Interface(), nil
+		}
+		copied := reflect.MakeMap(original.Type())
+
+		var err error
+		var child interface{}
+		iter := original.MapRange()
+		for iter.Next() {
+			key := iter.Key()
+			value := iter.Value()
+
+			if value.Kind() == reflect.Interface && value.IsNil() {
+				copied.SetMapIndex(key, value)
+				continue
+			}
+
+			child, err = copyValue(value)
+			if err != nil {
+				return nil, err
+			}
+			copied.SetMapIndex(key, reflect.ValueOf(child))
+		}
+		return copied.Interface(), nil
+
+	case reflect.Pointer:
+		if original.IsNil() {
+			return original.Interface(), nil
+		}
+		copied, err := copyValue(original.Elem())
+		if err != nil {
+			return nil, err
+		}
+		ptr := reflect.New(original.Type().Elem())
+		ptr.Elem().Set(reflect.ValueOf(copied))
+		return ptr.Interface(), nil
+
+	case reflect.Slice:
+		if original.IsNil() {
+			return original.Interface(), nil
+		}
+		copied := reflect.MakeSlice(original.Type(), original.Len(), original.Cap())
+		for i := 0; i < original.Len(); i++ {
+			val, err := copyValue(original.Index(i))
+			if err != nil {
+				return nil, err
+			}
+			copied.Index(i).Set(reflect.ValueOf(val))
+		}
+		return copied.Interface(), nil
+
+	case reflect.Struct:
+		copied := reflect.New(original.Type()).Elem()
+		for i := 0; i < original.NumField(); i++ {
+			elem, err := copyValue(original.Field(i))
+			if err != nil {
+				return nil, err
+			}
+			copied.Field(i).Set(reflect.ValueOf(elem))
+		}
+		return copied.Interface(), nil
+
+	case reflect.Func, reflect.Chan, reflect.UnsafePointer:
+		if original.IsNil() {
+			return original.Interface(), nil
+		}
+		return original.Interface(), nil
+
+	default:
+		return original.Interface(), fmt.Errorf("unsupported type %v", original)
+	}
+}