@quentinadam/assert

A simple assertion function.

Usage

import { assert, AssertionError } from '@quentinadam/assert';

assert(1 + 1 === 2); // passes

try {
  assert(1 + 1 === 3);
} catch (e) {
  // throws AssertionError
}

try {
  assert(1 + 1 === 3, 'Math is broken');
} catch (e) {
  // throws AssertionError with custom message
}

try {
  assert(1 + 1 === 3, new Error('Math is broken'));
} catch (e) {
  // throws a custom Error
}

const value: string | undefined = 'hello';
assert(value !== undefined); // narrows the type of value to string
value.toUpperCase(); // works