o/src/__tests__/size.spec.ts

common object helper functions

import size from '../size'
import { OObject } from '../types'

describe('size', (): void => {
  test('should return a number', (): void => {
    expect(typeof size({})).toBe('number')
  })

  test('should return the size of the object (number of keys)', (): void => {
    const objA = {
      a: 1,
      b: 2
    }
    const objB = {
      a: 1,
      b: 2,
      c: 3
    }

    expect(size(objA)).toBe(2)
    expect(size(objB)).toBe(3)
  })

  test('should throw TypeError for invalid arguments', (): void => {
    const invalidObj: unknown = 'testing'

    expect((): number => size(invalidObj as OObject))
      .toThrow(new TypeError('Expected Object, got string testing'))
  })
})