dcos-dygraphs/auto_tests/tests/fill_step_plot.js

dygraphs is a fast, flexible open source JavaScript charting library.

/**
 * @fileoverview Test if you give null values to dygraph with stepPlot
 * and fillGraph options enabled
 *
 * @author benoitboivin.pro@gmail.com (Benoit Boivin)
 */
import Dygraph from '../../src/dygraph';
import * as utils from '../../src/dygraph-utils';
import CanvasAssertions from './CanvasAssertions';
import Proxy from './Proxy';

describe("fill-step-plot", function() {

cleanupAfterEach();

var origFunc = utils.getContext;

beforeEach(function() {
  utils.getContext = function(canvas) {
    return new Proxy(origFunc(canvas));
  };
});

afterEach(function() {
  utils.getContext = origFunc;
});


it('testFillStepPlotNullValues', function() {
  var opts = {
    labels: ["x","y"],
    width: 480,
    height: 320,
    fillGraph: true,
    stepPlot: true
  };
  var data = [
    [1,3],
    [2,0],
    [3,8],
    [4,null],
    [5,9],
    [6,8],
    [7,6],
    [8,3]
  ];
  var graph = document.getElementById("graph");
  var g = new Dygraph(graph, data, opts);

  var htx = g.hidden_ctx_;
  var x1 = data[3][0];
  var y1 = data[2][1];
  var x2 = data[3][0];
  var y2 = 0;
  var xy1 = g.toDomCoords(x1, y1);
  var xy2 = g.toDomCoords(x2, y2);
  
  // Check if a line is drawn between the previous y and the bottom of the chart
  CanvasAssertions.assertLineDrawn(htx, xy1, xy2, {});
});

});