Assert.empty()

added in 0.5.0 • last revisions

Syntax

function empty(iterable: Iterable<unknown>, name?: string): void

Asserts that an array-like or iterable has no elements and throws an assertion error if it does.

Parameters
`iterable`	An iterable which may or may not be empty.
`name` Optional	A variable, property, or parameter name which, if specified, will print the name as part of the assertion error to make it more clear where the error originated.

Example

import { Assert } from 'potence';

function addElementsIfEmpty(array: number[]): number[] {
    Assert.empty(array);

    array.push(1, 2, 3);

    return array;
}

addElementsIfEmpty([]);   // OK, elements added
addElementsIfEmpty([1]);  // AssertionError: "Assertion failed: expected empty iterable but got iterable with 1 element"