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std/assert/assert_exists.ts

The Deno Standard Library
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// 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 that actual is not null or undefined. * If not then throw. * * @example * ```ts * import { assertExists } from "https://deno.land/std@$STD_VERSION/assert/assert_exists.ts"; * * assertExists("something"); // Doesn't throw * assertExists(undefined); // Throws * ``` */export function assertExists<T>( actual: T, msg?: string,): asserts actual is NonNullable<T> { if (actual === undefined || actual === null) { const msgSuffix = msg ? `: ${msg}` : "."; msg = `Expected actual: "${actual}" to not be null or undefined${msgSuffix}`; throw new AssertionError(msg); }}