d3_d_line_test.js

describe('#renderLines', function() {
  var xScale;
  var yScale;

  beforeEach(function() {
    xScale = d3.scale.linear().domain([0, 10]).range([0, 100]);
    yScale = d3.scale.linear().domain([0, 10]).range([0, 1000]);
  });

  it('renders lines correctly for a small 1-line data set', function() {
    var data = [
      [
        {x: 0, y: 0},
        {x: 0, y: 10},
        {x: 10, y: 10}
      ]
    ];

    renderLines(xScale, yScale, data);
    var line = document.getElementsByTagName('path')[0];
    assert.strictEqual(line.getAttribute('d'), 'M0,0L0,1000L100,1000');
  });

  it('renders lines correctly for a small 2-line data set', function() {
    var data = [
      [
        {x: 0, y: 0},
        {x: 0, y: 10},
        {x: 10, y: 10}
      ],
      [
        {x: 0, y: 0.251},
        {x: 1.25, y: 5},
        {x: 10, y: 6.2}
      ]
    ];

    renderLines(xScale, yScale, data);
    var lines = document.getElementsByTagName('path');
    assert.strictEqual(lines[0].getAttribute('d'), 'M0,0L0,1000L100,1000');
    assert.strictEqual(lines[1].getAttribute('d'), 'M0,25.1L12.5,500L100,620');
  });

  it('renders lines correctly for a 1-line data set with 15 data points', function() {
    var data = [
      [
        {x: 0, y: 0},
        {x: 0.5, y: 0.251},
        {x: 1, y: 1.2},
        {x: 1.5, y: 5},
        {x: 2, y: 5.01},
        {x: 2.5, y: 2.5},
        {x: 3, y: 2.666},
        {x: 3.5, y: 8.01},
        {x: 4, y: 1.01},
        {x: 4.5, y: 10},
        {x: 5, y: 9.99},
        {x: 5.5, y: 7.59},
        {x: 6, y: 8},
        {x: 6.5, y: 6.9},
        {x: 7, y: 7}
      ]
    ];

    renderLines(xScale, yScale, data);
    var line = document.getElementsByTagName('path')[0];
    assert.strictEqual(line.getAttribute('d'), 'M0,0L5,25.1L10,120L15,500L20,501L25,250L30,266.6L35,800.9999999999999L40,101L45,1000L50,999L55.00000000000001,759L60,800L65,690.0000000000001L70,700');
  });
});