Unit tests spying frequently called methods slow

[jzy3d]

• TestContinuousAndOnDemandRendering (approx. 20sec)
• TestDepthRange (approx. 30sec)

It seams this occur with objects that may be called frequently (Painter, Camera, View, etc)

[jzy3d]

Interesting discussions about mockito performance cost

• Mockito initialise performance mockito/mockito#2423
• https://majiehong.com/post/2021-07-11_mockito_performance_cost/
• https://medium.com/@ilyalim/a-quest-for-speed-fastening-up-mockito-ce8154b9ded7

[jzy3d]

Performance improves a lot when doing "manual mocks", i.e. override the class and method to spy instead of asking Mockito generate the spy. A 30s test dropped to < 1s.

Here we want to check how many time the method glDepthRange was called with which arguments :

public class GLMock_DepthRange extends GL{
  List<double[]> verify_glDepthRange = new ArrayList<>();
  
  @Override
  public void glDepthRange(double near_val, double far_val) {
    super.glDepthRange(near_val, far_val);
    double[] args = {near_val, far_val};
    verify_glDepthRange.add(args);
  }
  public List<double[]> verify_glDepthRange() {
    return verify_glDepthRange;
  }
  public void clear_glDepthRange() {
    verify_glDepthRange.clear();
  }
}

And use it as follow

public class TestAxisBox {
  @Test
  public void whenRenderAxis_DepthRangeModifiedByAxis() {
    GLMock_DepthRange glMock = new GLMock_DepthRange();

    // Given a surface chart with a mock GL injected for spying calls to glDepthRange
    EmulGLChartFactory factory = EmulGLChartFactory.forGL(glMock);
    Chart chart = factory.newChart(Quality.Advanced());
    Shape surface = SampleGeom.surface();
    chart.add(surface);
    glMock.clear_glDepthRange();

    // ----------------------------------------------
    // When : render axis
    chart.getView().getAxis().draw(chart.getPainter());

    // ----------------------------------------------
    // Then axis will update depth range
    double[] configForAxis = {AxisBox.NO_OVERLAP_DEPTH_RATIO, 1};
    double[] configForNothing = {0, 1};

    Assert.assertTrue(Arrays.equals(glMock.verify_glDepthRange().get(0), configForAxis));
    Assert.assertTrue(Arrays.equals(glMock.verify_glDepthRange().get(1), configForNothing));

  }
}