moy-fp/test/Math/mean.test.js

A functional programming library.

import __ from '../../src/Function/__'
/**
 * [Number] -> Number
 */
import mean from '../../src/Math/mean'

test('mean(not using __), not empty array', () => {
  expect(
    mean([1, 2, 3, 4])
  ).toBe(2.5)
})

test('mean(using __), empty array', () => {
  expect(
    mean([])
  ).toBe(NaN)
})

test('mean(using __), not empty array', () => {
  expect(
    mean(__)([1, 2, 3, 4])
  ).toBe(2.5)
})