std/assert/assert.ts
2024-04-29 11:57:30 +09:00

21 lines
562 B
TypeScript

// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
// This module is browser compatible.
import { AssertionError } from "./assertion_error.ts";
/**
* Make an assertion, error will be thrown if `expr` does not have truthy value.
*
* @example
* ```ts
* import { assert } from "@std/assert/assert";
*
* assert("hello".includes("ello")); // Doesn't throw
* assert("hello".includes("world")); // Throws
* ```
*/
export function assert(expr: unknown, msg = ""): asserts expr {
if (!expr) {
throw new AssertionError(msg);
}
}