Proper way to use simplelog in #[test] code

help
1

I have code that uses logger extensively. I'd like my #[test] sections to send their logger output to standard output, where it would be hidden unless the test fails.
There are some problems. First, if a test does an init of a CombinedLogger, that clashes with other tests in the same test run. There's only one test executable. We can get around that by ignoring the output from init(). Second, if I do this:

let _ = simplelog::CombinedLogger::init(
        vec![
            simplelog::TermLogger::new(LevelFilter::Debug, simplelog::Config::default(), simplelog::TerminalMode::Stdout, simplelog::ColorChoice::Auto),]
    );

it really logs to the terminal, not standard output, so all the logger output shows up rather than being captured for successful tests.

There's probably some simple way to do this.

2

Write a logger that sends the output where you want it.

struct LoggerForTests;

impl log::Log for LoggerForTests {
    fn enabled(&self, _: &log::Metadata<'_>) -> bool {
        true
    }
   fn log(&self, record: &log::Record<'_>) {
        eprintln!(
            "[{level}] {msg}",
            level = record.level(),
            msg = record.args()
        );
    }
    fn flush(&self) {}
}
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