fix: update to nil pointer (#78)

Author: 23doors

change_value.go

@@ -158,6 +158,8 @@ func (c *ChangeValue) Set(value reflect.Value, convertCompatibleTypes bool) {
 			} else {
 				c.target.Set(value)
 			}
+		} else if c.target.Kind() == reflect.Ptr {
+			c.target.Set(reflect.Zero(c.target.Type()))
 		} else if !c.target.IsZero() {
 			t := c.target.Elem()
 			t.Set(reflect.Zero(t.Type()))

patch_test.go

@@ -126,6 +126,12 @@ func TestPatch(t *testing.T) {
 			nil,
 		},
 		{
+			"struct-string-pointer-update-to-nil", &tstruct{Pointer: sptr("test")}, &tstruct{Pointer: nil},
+			diff.Changelog{
+				diff.Change{Type: diff.UPDATE, Path: []string{"pointer"}, From: sptr("test"), To: nil},
+			},
+			nil,
+		}, {
 			"struct-generic-slice-insert", &tstruct{Values: []string{"one"}}, &tstruct{Values: []string{"one", "two"}},
 			diff.Changelog{
 				diff.Change{Type: diff.CREATE, Path: []string{"values", "1"}, From: nil, To: "two"},