import assert from 'node:assert'; import lodashStable from 'lodash'; import { falsey, args, slice, symbol, realm } from './utils'; import isNumber from '../src/isNumber'; describe('isNumber', () => { it('should return `true` for numbers', () => { assert.strictEqual(isNumber(0), true); assert.strictEqual(isNumber(Object(0)), true); assert.strictEqual(isNumber(NaN), true); }); it('should return `false` for non-numbers', () => { const expected = lodashStable.map(falsey, (value) => typeof value === 'number'); const actual = lodashStable.map(falsey, (value, index) => index ? isNumber(value) : isNumber(), ); assert.deepStrictEqual(actual, expected); assert.strictEqual(isNumber(args), false); assert.strictEqual(isNumber([1, 2, 3]), false); assert.strictEqual(isNumber(true), false); assert.strictEqual(isNumber(new Date()), false); assert.strictEqual(isNumber(new Error()), false); assert.strictEqual(isNumber(slice), false); assert.strictEqual(isNumber({ a: 1 }), false); assert.strictEqual(isNumber(/x/), false); assert.strictEqual(isNumber('a'), false); assert.strictEqual(isNumber(symbol), false); }); it('should work with numbers from another realm', () => { if (realm.number) { assert.strictEqual(isNumber(realm.number), true); } }); });