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24 lines
688 B
TypeScript
24 lines
688 B
TypeScript
// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
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// This module is browser compatible.
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import { AssertionError } from "./assertion_error.ts";
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/**
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* Make an assertion, error will be thrown if `expr` does not have truthy value.
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*
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* @example Usage
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* ```ts no-eval
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* import { assert } from "@std/assert/assert";
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*
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* assert("hello".includes("ello")); // Doesn't throw
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* assert("hello".includes("world")); // Throws
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* ```
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*
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* @param expr The expression to test.
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* @param msg The optional message to display if the assertion fails.
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*/
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export function assert(expr: unknown, msg = ""): asserts expr {
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if (!expr) {
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throw new AssertionError(msg);
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}
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}
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