Function verify_that_code

pub fn verify_that_code<'a, S>(code: S) -> Spec<'a, Code<S>, CollectFailures>
where
    S: FnOnce(),

Starts an assertion for some piece of code in the CollectFailures mode.

It takes a closure and wraps it into a Spec. On the Spec any assertion method that is implemented for closures can be called.

Assertions started with verify_that_code() will collect AssertFailures for all failing assertions. The collected failures can be queried by calling one of the methods failures or display_failures on the Spec.

In comparison to using the macro verify_that_code! calling this function does not set a name for the expression and does not set the code location of the assertion. In failure messages the generic word “the closure” is used. To set a specific text for the expression the method named must be called explicitly.

Examples

use asserting::prelude::*;

fn divide(a: i32, b: i32) -> i32 {
    a / b
}

let failures = verify_that_code(|| { divide(7, 3); })
    .does_not_panic()
    .failures();

assert_that!(failures).is_empty();

let failures = verify_that_code(|| { divide(7, 0); })
    .does_not_panic()
    .display_failures();

assert_that!(failures).contains_exactly([
    r#"assertion failed: expected the closure to not panic, but did panic
  with message: "attempt to divide by zero"
"#
]);

let failures = verify_that_code(|| { divide(7, 0); })
    .panics_with_message("division by zero")
    .display_failures();

assert_that!(failures).contains_exactly([
    r#"assertion failed: expected the closure to panic with message "division by zero"
   but was: "attempt to divide by zero"
  expected: "division by zero"
"#
]);