rust - How to initialize the logger for integration tests?

Question

I have a crate with production code in the src directory and integration tests in the tests directory. The production code uses log macros.

I would like to init a global logger when running the integration tests (e.g. env_logger::init().unwrap();) There are several tests and the test order is not defined, so I don't know in which test I should put the initialize command.

Is there any way I can do this nicely? Perhaps by overriding the tests main function?

Answer 1

You can use something like this:

use std::sync::Once;

static INIT: Once = Once::new();

/// Setup function that is only run once, even if called multiple times.
fn setup() {
    INIT.call_once(|| {
        env_logger::init().unwrap();
    });
}

Then simply call setup() in the beginning of each test.

Originally based on this blogpost.