How to Ignore Tests and Run Them Conditionally

Add the #[ignore] attribute to a test function to skip it during normal runs, then use cargo test -- --ignored to execute only those skipped tests.

#[test]
#[ignore]
fn expensive_test() {
    // code that takes an hour to run
}

// Run ignored tests only:
// cargo test -- --ignored

To run a specific ignored test by name, use:

cargo test -- --ignored expensive_test

To run all tests including ignored ones, use:

cargo test -- --include-ignored

Ignoring tests lets you mark slow or flaky tests to skip them during regular checks so your workflow stays fast. You can then run just those skipped tests on demand when you need to verify them. Think of it like putting a 'Do Not Disturb' sign on a room until you're ready to clean it.