fn capture_two_streams(
        filter1: EnvFilter,
        filter2: EnvFilter,
        workload: impl FnOnce(),
    ) -> (Vec<String>, Vec<String>) {
        let writer1 = Arc::new(Mutex::new(Vec::new()));
        let writer1_captured = Arc::clone(&writer1);
        let writer2 = Arc::new(Mutex::new(Vec::new()));
        let writer2_captured = Arc::clone(&writer2);

        let layer1 = fmt::layer()
            .with_target(false)
            .with_ansi(false)
            .without_time()
            .with_writer(move || SynchronizedWriter::new(Arc::clone(&writer1_captured)));

        let layer2 = fmt::layer()
            .json()
            .with_target(false)
            .with_ansi(false)
            .without_time()
            .with_writer(move || SynchronizedWriter::new(Arc::clone(&writer2_captured)));

        let subscriber = tracing_subscriber::Registry::default()
            .with(FilteredLayer::new(filter1.and_then(layer1)))
            .with(FilteredLayer::new(filter2.and_then(layer2)));

        tracing::subscriber::with_default(subscriber, workload);

        let lines = |writer: Arc<Mutex<Vec<_>>>| {
            std::str::from_utf8(&writer.lock().unwrap())
                .unwrap()
                .to_string()
                .trim_end()
                .split('\n')
                .into_iter()
                .map(String::from)
                .collect()
        };

        (lines(writer1), lines(writer2))
    }
// capture_two_streams is a test helper that sets up two independent tracing subscribers, each with
// a different filtering level and returns a tuple of the emitted lines for the respective streams.
//
// The first stream uses a textual format, the second stream uses a json format (just to make it clear they are
// indeed completely different exporters).
capture_two_streams is a test helper that sets up two independent tracing subscribers, each with
a different filtering level and returns a tuple of the emitted lines for the respective streams.

The first stream uses a textual format, the second stream uses a json format (just to make it clear they are
indeed completely different exporters).
capture_two_streams is a test helper that sets up two independent tracing subscribers each with a different filtering level and returns a tuple of the emitted lines for the respective streams . The first stream uses a textual format the second stream uses a json format ( just to make it clear they are indeed completely different exporters ) .
fn capture_two_streams(
        filter1: EnvFilter,
        filter2: EnvFilter,
        workload: impl FnOnce(),
    ) -> (Vec<String>, Vec<String>) {
        let writer1 = Arc::new(Mutex::new(Vec::new()));
        let writer1_captured = Arc::clone(&writer1);
        let writer2 = Arc::new(Mutex::new(Vec::new()));
        let writer2_captured = Arc::clone(&writer2);
        let layer1 = fmt::layer()
            .with_target(false)
            .with_ansi(false)
            .without_time()
            .with_writer(move || SynchronizedWriter::new(Arc::clone(&writer1_captured)));
        let layer2 = fmt::layer()
            .json()
            .with_target(false)
            .with_ansi(false)
            .without_time()
            .with_writer(move || SynchronizedWriter::new(Arc::clone(&writer2_captured)));
        let subscriber = tracing_subscriber::Registry::default()
            .with(FilteredLayer::new(filter1.and_then(layer1)))
            .with(FilteredLayer::new(filter2.and_then(layer2)));
        tracing::subscriber::with_default(subscriber, workload);
        let lines = |writer: Arc<Mutex<Vec<_>>>| {
            std::str::from_utf8(&writer.lock().unwrap())
                .unwrap()
                .to_string()
                .trim_end()
                .split('\n')
                .into_iter()
                .map(String::from)
                .collect()
        };
        (lines(writer1), lines(writer2))
    }
fn capture_two_streams ( filter1 : EnvFilter , filter2 : EnvFilter , workload : impl FnOnce ( ) , ) -> ( Vec < String > , Vec < String > ) { let writer1 = Arc :: new ( Mutex :: new ( Vec :: new ( ) ) ) ; let writer1_captured = Arc :: clone ( & writer1 ) ; let writer2 = Arc :: new ( Mutex :: new ( Vec :: new ( ) ) ) ; let writer2_captured = Arc :: clone ( & writer2 ) ; let layer1 = fmt :: layer ( ) . with_target ( false ) . with_ansi ( false ) . without_time ( ) . with_writer ( move | | SynchronizedWriter :: new ( Arc :: clone ( & writer1_captured ) ) ) ; let layer2 = fmt :: layer ( ) . json ( ) . with_target ( false ) . with_ansi ( false ) . without_time ( ) . with_writer ( move | | SynchronizedWriter :: new ( Arc :: clone ( & writer2_captured ) ) ) ; let subscriber = tracing_subscriber :: Registry :: default ( ) . with ( FilteredLayer :: new ( filter1 . and_then ( layer1 ) ) ) . with ( FilteredLayer :: new ( filter2 . and_then ( layer2 ) ) ) ; tracing :: subscriber :: with_default ( subscriber , workload ) ; let lines = | writer : Arc < Mutex < Vec < _ > > > | { std :: str :: from_utf8 ( & writer . lock ( ) . unwrap ( ) ) . unwrap ( ) . to_string ( ) . trim_end ( ) . split ( '\n' ) . into_iter ( ) . map ( String :: from ) . collect ( ) } ; ( lines ( writer1 ) , lines ( writer2 ) ) }
capture_two_streams is a test helper that sets up two independent tracing subscribers, each with
a different filtering level and returns a tuple of the emitted lines for the respective streams.
capture_two_streams is a test helper that sets up two independent tracing subscribers each with a different filtering level and returns a tuple of the emitted lines for the respective streams .
filter1
EnvFilter
filter2
EnvFilter
workload
impl FnOnce()
filter1
EnvFilter
filter2
EnvFilter
workload
impl FnOnce()