File plugin.filler.tests.js

test/specs/plugin.filler.tests.js:None–None

describe('Plugin.filler', function() {
  const fillerPluginRegisterWarning = 'Tried to use the \'fill\' option without the \'Filler\' plugin enabled. Please import and register the \'Filler\' plugin and make sure it is not disabled in the options';
  function decodedFillValues(chart) {
    return chart.data.datasets.map(function(dataset, index) {