file-commons/src/formatRawFileSize.test.ts

import * as fc from 'fast-check'
import formatRawFileSize from './formatRawFileSize'

it('should exist', () => {
  expect(formatRawFileSize).toBeDefined()
})

it('should be a function', () => {
  expect(typeof formatRawFileSize).toBe('function')
})

it('should take 1 argument', () => {
  expect(formatRawFileSize).toHaveLength(1)
})

it('should throw an error on non-numeric arguments', () => {
  fc.assert(
    fc.property(
      fc.anything().filter(v => typeof v !== 'number'),
      v => {
        expect(() => formatRawFileSize(v)).toThrow(TypeError)
      }
    )
  )
})

it('should throw an error on NaN', () => {
  expect(() => formatRawFileSize(NaN)).toThrow(RangeError)
})

it('should return string on numeric values', () => {
  fc.assert(
    fc.property(
      fc.integer(),
      v => {
        expect(typeof formatRawFileSize(v)).toBe('string')
      }
    )
  )
})

it('should format numeric values', () => {
  fc.assert(
    fc.property(
      fc.integer(),
      v => {
        expect(formatRawFileSize(v)).toMatch(/^-?\d[,\d]* .?B$/)
      }
    )
  )
})