package main import ( "flag" "testing" "github.com/stretchr/testify/require" ) func TestMultiStringFlagAppendsOnSet(t *testing.T) { var concrete MultiStringFlag var iface flag.Value iface = &concrete require.NoError(t, iface.Set("foo")) require.NoError(t, iface.Set("bar")) require.Equal(t, MultiStringFlag{"foo", "bar"}, concrete) }