Function faux::matcher::eq

pub fn eq<Arg, Expected>(expected: Expected) -> impl ArgMatcher<Arg> where
    Arg: Borrow<Expected>,
    Expected: Debug + PartialEq, 

Returns an equality matcher.

Returns a matcher that compares Arg using equality across borrows.

Unlike eq_against, it only allows equality matching for the same type. This comes at the benefit of being able to match across borrows.

Examples

Basic usage

use faux::matcher::{self, ArgMatcher};

let eq_four = matcher::eq(4);
assert!(eq_four.matches(&4));
assert!(!eq_four.matches(&5));

Matching across borrows

use std::rc::Rc;
use faux::matcher::{self, ArgMatcher};

// `Rc<T>` implements `Borrow<T>`
assert!(matcher::eq(5).matches(&Rc::new(5)));

// `&T` implements `Borrow<T>`
let ref_of_ref: &&i32 = &&5;
assert!(matcher::eq(5).matches(ref_of_ref));

Usage within when!

For convenience, faux::when! defaults to the eq matcher. See the matcher syntax for more information.

// `_` means the `any` matcher
faux::when!(my_struct.some_method(2)).then_return(5);

// we can also call it manually within `when!`
faux::when!(my_struct.some_method(_ = faux::matcher::eq(2)))
    .then_return(5);

// or call it manually outside `when!`
faux::when!(my_struct.some_method)
    .with_args((matcher::eq(2),)).then_return(5);