Struct LogCapture

pub struct LogCapture { /* private fields */ }

A reusable log capturing struct for unit tests. Captures logs written during test execution for assertions.

Examples

use sp_tracing::test_log_capture::LogCapture;
use std::io::Write;

let mut log_capture = LogCapture::new();
writeln!(log_capture, "Test log message").unwrap();
assert!(log_capture.contains("Test log message"));

Implementations

impl LogCapture

pub fn new() -> Self

Creates a new LogCapture instance with an internal buffer.

Examples

use sp_tracing::test_log_capture::LogCapture;

let log_capture = LogCapture::new();
assert!(log_capture.get_logs().is_empty());

pub fn contains(&self, expected: &str) -> bool

Checks if the captured logs contain a specific substring.

Examples

use sp_tracing::test_log_capture::LogCapture;
use std::io::Write;

let mut log_capture = LogCapture::new();
writeln!(log_capture, "Hello, world!").unwrap();
assert!(log_capture.contains("Hello"));
assert!(!log_capture.contains("Goodbye"));

pub fn get_logs(&self) -> String

Retrieves the captured logs as a String.

Examples

use sp_tracing::test_log_capture::LogCapture;
use std::io::Write;

let mut log_capture = LogCapture::new();
writeln!(log_capture, "Log entry").unwrap();
assert_eq!(log_capture.get_logs().trim(), "Log entry");

pub fn writer(&self) -> Self

Returns a clone of the internal buffer for use in MakeWriter.

Trait Implementations

impl<'a> MakeWriter<'a> for LogCapture

fn make_writer(&'a self) -> Self::Writer

Provides a MakeWriter implementation for tracing_subscriber.

type Writer = LogCapture

The concrete io::Write implementation returned by make_writer.

fn make_writer_for(&'a self, meta: &Metadata<'_>) -> Self::Writer

Returns a Writer for writing data from the span or event described by the provided Metadata.

impl Write for LogCapture

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

Writes log data into the internal buffer.

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

Flushes the internal buffer (no-op in this implementation).

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.