Skip to main content

CollectionAssertion

fluent_assertions::assertions::collection_assertion

Trait CollectionAssertion 

Source 
pub trait CollectionAssertion<T> {
    // Required methods
    fn be_empty(self) -> Self;
    fn not_be_empty(self) -> Self;
    fn have_length(self, length: usize) -> Self;
    fn contain(self, expected: &T) -> Self
       where T: PartialEq;
}
Expand description

Specific assertions for list-like collections (Vec, arrays and slices).

These live on a trait rather than being inherent methods because the string assertions are implemented for the blanket impl<T: AsRef<str>> Assertion<T>. Coherence conservatively assumes Vec<_> / &[_] might implement AsRef<str> in the future, so inherent methods sharing the same names (be_empty, contain, …) would clash with the string impl. A trait sidesteps that: it is implemented only for the concrete Assertion<Vec<T>>, Assertion<&[T]>, Assertion<[T; N]> and Assertion<&Vec<T>>, never for &str / String.

Required Methods§

Source

fn be_empty(self) -> Self

Asserts that the collection is empty

§Examples
use fluent_assertions::*;
Vec::<i32>::new().should().be_empty();
Source

fn not_be_empty(self) -> Self

Asserts that the collection is not empty

§Examples
use fluent_assertions::*;
vec![1, 2, 3].should().not_be_empty();
Source

fn have_length(self, length: usize) -> Self

Asserts that the collection has a given length

§Examples
use fluent_assertions::*;
[1, 2, 3].should().have_length(3);
Source

fn contain(self, expected: &T) -> Self
where T: PartialEq,

Asserts that the collection contains a given element

§Examples
use fluent_assertions::*;
vec![1, 2, 3].should().contain(&2);

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§