Issue #3 added a test for lights

src/lights.js

@@ -2,7 +2,7 @@ import vtkLight from '@kitware/vtk.js/Rendering/Core/Light.js'
 
 export function setupLights (url, renderer) {
   const spotLightOn = url.searchParams.get('spotlight')
-  if (spotLightOn != null) {
+  if (spotLightOn !== null) {
     const light0 = vtkLight.newInstance()
     light0.setLightTypeToSceneLight()
     light0.setFocalPoint(150, 0, 0)

src/test/lights.test.Spec.js

@@ -0,0 +1,22 @@
+import vtkRenderer from '@kitware/vtk.js/Rendering/Core/Renderer.js'
+import { setupLights } from '../lights.js';
+
+describe('Set up Lights Test', () => {
+ const rendererns = vtkRenderer.newInstance()
+ const urlns = new URL('https://test.com?nospjjotlight')
+ const lightsBefore = rendererns.getLights().length
+ it('should run without spotlight', () => {
+   setupLights (urlns, rendererns)
+   const lightsAfter = rendererns.getLights().length
+   console.log(lightsBefore + ' : ' + lightsAfter)
+   expect(lightsAfter).toBe(lightsBefore)
+    });
+
+ const url = new URL('https://test.com?spotlight')
+ const renderer = vtkRenderer.newInstance()
+ const lightsBeforeSpot = renderer.getLights().length
+ it('should add a spotlight', () => {
+   setupLights (url, renderer)
+   expect(renderer.getLights().length).toBe(lightsBeforeSpot + 1)
+    });
+});