package mergo_test import ( "encoding/json" "testing" "github.com/imdario/mergo" ) func TestIssue17MergeWithOverwrite(t *testing.T) { var ( request = `{"timestamp":null, "name": "foo"}` maprequest = map[string]interface{}{ "timestamp": nil, "name": "foo", "newStuff": "foo", } ) var something map[string]interface{} if err := json.Unmarshal([]byte(request), &something); err != nil { t.Errorf("Error while Unmarshalling maprequest: %s", err) } if err := mergo.MergeWithOverwrite(&something, maprequest); err != nil { t.Errorf("Error while merging: %s", err) } }