test.js

const test = require('ava')
const React = require('react')
const isStream = require('is-stream')
const repng = require('./index')

// fixture
const Grid = ({
  width = 256,
  height = 256,
  size = 2
}) => {
  const rects = Array.from({ length: 32 / size })
    .map((n, y) => (
      Array.from({ length: 32 / size })
        .map((n, x) => (
          React.createElement('rect', {
            width: size,
            height: size,
            fill: (x % 2 === (y % 2 ? 1 : 0)) ? 'black' : 'transparent',
            x: size * x,
            y: size * y,
          })
        ))
    ))

  return (
    React.createElement('svg', {
      viewBox: '0 0 32 32',
      width,
      height,
    }, rects)
  )
}

test('is a function', t => {
  t.is(typeof repng, 'function')
})

test('returns a stream', async t => {
  const width = 128
  const height = width

  const result = await repng(Grid, {
    width,
    height,
    props: {
      width,
      height,
    }
  })

  t.true(isStream(result))
})