@std/assert@1.0.12
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Common assertion functions, especially useful for testing

Published

2 days ago (1.0.12)

function assertExists



assertExists<T>(actual: T,
msg?: string,
): asserts actual is NonNullable<T>

Make an assertion that actual is not null or undefined. If not then throw.

Examples

import { assertExists } from "@std/assert";

assertExists("something"); // Doesn't throw
assertExists(undefined); // Throws

The type of the actual value.



actual: T

The actual value to check.

optional



msg: string

The optional message to include in the error if the assertion fails.

asserts actual is NonNullable<T>

Add Package

deno add jsr:@std/assert

Import symbol

import { assertExists } from "@std/assert/exists";

---- OR ----

Import directly with a jsr specifier

import { assertExists } from "jsr:@std/assert/exists";

Add Package

npx jsr add @std/assert

Import symbol

import { assertExists } from "@std/assert/exists";

Add Package

yarn dlx jsr add @std/assert

Import symbol

import { assertExists } from "@std/assert/exists";

Add Package

pnpm dlx jsr add @std/assert

Import symbol

import { assertExists } from "@std/assert/exists";

Add Package

bunx jsr add @std/assert

Import symbol

import { assertExists } from "@std/assert/exists";