Struct slog_term::TestStdoutWriter

pub struct TestStdoutWriter;

Replacement for std::io::stdout() for when output capturing by rust’s test harness is required.

Note

Due to the way that output capturing works in Rust, using this class has no effect if the logger is later passed to another thread that is not controlled by Rust’s testing framework. See rust-lang/rust#42474 for reference.

For this reason, combining this drain with Async, for example, has no effect.

Example

#[test]
fn test_logger() {
    let logger = {
        let decorator = slog_term::PlainSyncDecorator::new(slog_term::TestStdoutWriter);
        let drain = slog_term::FullFormat::new(decorator).build().fuse();

        Logger::root_typed(drain, o!())
    };
    info!(logger, "Hi from logger test");
}

Trait Implementations

impl Write for TestStdoutWriter

fn write(&mut self, data: &[u8]) -> Result<usize>

Write a buffer into this writer, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.