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5803cc9172
* BREAKING(assert): remove `assert` from module names * work * fix * work * work * tweaks * fix
27 lines
777 B
TypeScript
27 lines
777 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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/** Assertion condition for {@linkcode assertFalse}. */
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export type Falsy = false | 0 | 0n | "" | null | undefined;
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/**
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* Make an assertion, error will be thrown if `expr` 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 { assertFalse } from "@std/assert";
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*
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* assertFalse(false); // Doesn't throw
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* assertFalse(true); // 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 assertFalse(expr: unknown, msg = ""): asserts expr is Falsy {
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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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