Function writeImageFile

test/unit/visual/visualTest.js:22–25

(filename, base64Data)

const BG = '#F0F';

function writeImageFile(filename, base64Data) {
  const prefix = /^data:image\/\w+;base64,/;
  writeFile(filename, base64Data.replace(prefix, ''), 'base64');
}

function toBase64(img) {
  return img.canvas.toDataURL();