How should I perform unit testing for StreamSink?

[kulame]

i want to write a unittest for StreamSink, how can i mock the struct?

[fzyzcjy]

Hi, could you please elaborate it a bit more? For example, unit test Rust code or Dart code, etc (e.g. dart - use mocktail/mockito/etc)

[niuhuan]

I want take a unit test for rust function. I need mock StreamSink

mod tests {
    use crate::frb_generated::StreamSink;

    #[tokio::test]
    async fn test_import_data() {
        let home = std::env::var_os("HOME").unwrap().to_str().unwrap().to_string();
        let progress_sink = StreamSink::new();
        let path = format!("{home}/Downloads/data.zip");
        super::import_data(progress_sink, path.as_str()).await.unwrap();
    }
}

[niuhuan]

I use enumeration, but it doesn't look good either

#[derive(Clone)]
pub enum ImportNotifer {
    StreamSink(StreamSink<String>),
    #[cfg(test)]
    Print,
}   

impl ImportNotifer {
    pub fn add(&self, message: String) -> anyhow::Result<()> {
        match self {
            ImportNotifer::StreamSink(sink) => {
                sink.add(message).map_err(|e| anyhow::anyhow!(e))?;
                Ok(())
            },
            #[cfg(test)]
            ImportNotifer::Print => {
                println!("{}", message);
                Ok(())
            },
        }
    }
}

[fzyzcjy]

Hmm, one way may be let the rust function call a inner rust function, and ut on that inner function