Spy 
Documentation
Spy crate is inspired by such famous Javascript testing tools
as Jasmine and Sinon.js. It provides easy configurable spies
with predefined behaviour.
#[test]
fn iterator_all_test() {
let integers = vec![0i32, 1i32, 2i32];
let (spy_fn, spy) = spy!(|n| n % 2 == 0);
let res = integers.iter().all(spy_fn);
assert!(!res, "should be false");
let snapshot = spy.snapshot();
assert!(snapshot.called(), "should be called");
assert!(
snapshot.called_with(&(&1i32)),
"should be called with 1i32 at least once"
);
assert!(
!snapshot.each_called_with(&(&1i32)),
"should be called with different arguments"
);
assert_eq!(snapshot.all_calls(), &vec![(&0i32), (&1i32)]);
assert_eq!(snapshot.first_call().expect("should be Some"), &(&0i32));
assert_eq!(snapshot.last_call().expect("should be Some"), &(&1i32));
assert_eq!(snapshot.nth_call(1).expect("should be Some"), &(&1i32));
}
LICENSE
Spy is licensed under MIT and Apache-2.0 license