Assert.notNull()

added in 0.0.1 • updated in 0.4.0 • last revisions

Syntax

function notNull<T>(value: T, name?: string): void

Asserts that a value isn’t null or undefined and throws an assertion error if it is.

Parameters
`value`	The value to check.
`name` Optional	A variable, property, or parameter name which, if specified, will print the name as part of the assertion error to make it more clear where the error originated.

Example

import { Assert } from 'potence';

function doSomething(arg: string | null | undefined) {
    Assert.notNull(arg, 'arg');

    // ...
}

doSomething(123);   // OK
doSomething(null);  // AssertionError: "Assertion failed: expected arg to be non-null but was null"

Remarks

This function is a TypeScript assertion function meaning it behaves exactly the same as if (value != null) { ... }, narrowing the type to exclude null and undefined if possible.