#[cfg(test)]
#[cfg(feature = "builder")]
mod test {
    use lettre::{transport::stub::StubTransport, Message};

    #[cfg(feature = "tokio02")]
    use tokio02_crate as tokio;

    #[test]
    fn stub_transport() {
        use lettre::Transport;
        let sender_ok = StubTransport::new_ok();
        let sender_ko = StubTransport::new_error();
        let email = Message::builder()
            .from("NoBody <nobody@domain.tld>".parse().unwrap())
            .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
            .to("Hei <hei@domain.tld>".parse().unwrap())
            .subject("Happy new year")
            .body(String::from("Be happy!"))
            .unwrap();

        sender_ok.send(&email).unwrap();
        sender_ko.send(&email).unwrap_err();
    }

    #[cfg(feature = "async-std1")]
    #[async_std::test]
    async fn stub_transport_asyncstd1() {
        use lettre::AsyncStd1Transport;

        let sender_ok = StubTransport::new_ok();
        let sender_ko = StubTransport::new_error();
        let email = Message::builder()
            .from("NoBody <nobody@domain.tld>".parse().unwrap())
            .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
            .to("Hei <hei@domain.tld>".parse().unwrap())
            .subject("Happy new year")
            .date("Tue, 15 Nov 1994 08:12:31 GMT".parse().unwrap())
            .body(String::from("Be happy!"))
            .unwrap();

        sender_ok.send(email.clone()).await.unwrap();
        sender_ko.send(email).await.unwrap_err();
    }

    #[cfg(feature = "tokio02")]
    #[tokio::test]
    async fn stub_transport_tokio02() {
        use lettre::Tokio02Transport;

        let sender_ok = StubTransport::new_ok();
        let sender_ko = StubTransport::new_error();
        let email = Message::builder()
            .from("NoBody <nobody@domain.tld>".parse().unwrap())
            .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
            .to("Hei <hei@domain.tld>".parse().unwrap())
            .subject("Happy new year")
            .date("Tue, 15 Nov 1994 08:12:31 GMT".parse().unwrap())
            .body(String::from("Be happy!"))
            .unwrap();

        sender_ok.send(email.clone()).await.unwrap();
        sender_ko.send(email).await.unwrap_err();
    }
}