#[macro_export] macro_rules! assert_panics { ($e:expr) => {{ use std::panic::{catch_unwind}; use std::stringify; let expr_string = stringify!($e); // Note: We cannot manipulate the panic hook here, because it is global and the test // suite is run in parallel, which leads to race conditions in the sense // that some regular tests that panic might not output anything anymore. // Unfortunately this means that output is still printed to stdout if // we run cargo test -- --nocapture. But Cargo does not forward this if the test // binary is not run with nocapture, so it is somewhat acceptable nonetheless. let result = catch_unwind(|| $e); if result.is_ok() { panic!("assert_panics!({}) failed: the expression did not panic.", expr_string); } }}; }