test.js

'use strict'

const test = require('tape')
const staticProps = require('static-props')

class Point2d {
  constructor (x, y, label) {
    const color = 'red'

    const norm = () => x * x + y * y

    staticProps(this)({label, color, norm})

    const enumerable = true
    staticProps(this)({x, y}, enumerable)
  }
}

staticProps(Point2d)({ dim: 2 })

const norm = (x, y) => x * x + y * y
staticProps(Point2d)({ norm: () => norm })

test('staticProps', (t) => {
  t.plan(10)

  const p = new Point2d(1, 2, 'A')

  t.equal(p.x, 1, 'assigns prop "x"')
  t.equal(p.y, 2, 'assigns prop "y"')
  t.equal(p.label, 'A', 'assigns prop "label"')
  t.equal(p.color, 'red', 'assigns prop "color"')
  t.equal(p.norm, 5, 'assigns prop "norm" with a getter')

  t.throws(() => { p.label = 'B' }, /TypeError: Cannot assign to read only property/, 'static prop cannot be modified')

  t.ok(p.propertyIsEnumerable('x'), 'prop "x" is enumerable')
  t.ok(p.propertyIsEnumerable('y'), 'prop "y" is enumerable')
  t.equal(Point2d.dim, 2, 'assigns static attribute')
  t.equal(Point2d.norm(1, 2), 5, 'assigns static method')
})