vtkMapper.setResolveCoincidentTopologyPolygonOffsetParameters errors

Sources/Rendering/Core/Mapper/CoincidentTopologyHelper.js

@@ -29,7 +29,10 @@ const staticOffsetModel = {
   Line: { factor: 1, offset: -1 },
   Point: { factor: 0, offset: -2 },
 };
-const staticOffsetAPI = {};
+const noOp = () => undefined;
+const staticOffsetAPI = {
+  modified: noOp,
+};
 
 addCoincidentTopologyMethods(
   staticOffsetAPI,

Sources/Rendering/Core/Mapper/test/testCoincidentTopologyHelper.js

@@ -0,0 +1,38 @@
+import test from 'tape';
+import testUtils from 'vtk.js/Sources/Testing/testUtils';
+
+import vtkMapper from 'vtk.js/Sources/Rendering/Core/Mapper';
+
+test('Test calling CoincidentTopologyHelper static functions', async (t) => {
+  const gc = testUtils.createGarbageCollector(t);
+
+  // set back to starting/default values to avoid side effects for other tests
+  const startingParameters =
+    vtkMapper.getResolveCoincidentTopologyPolygonOffsetParameters();
+  vtkMapper.setResolveCoincidentTopologyPolygonOffsetParameters({
+    factor: -3,
+    offset: -3,
+  });
+  vtkMapper.setResolveCoincidentTopologyPolygonOffsetParameters(
+    startingParameters
+  );
+  const endingParameters =
+    vtkMapper.getResolveCoincidentTopologyPolygonOffsetParameters();
+  t.deepEqual(
+    startingParameters,
+    endingParameters,
+    'Initial PolygonOffset parameters after get and set are matching'
+  );
+
+  const startingLineParameters =
+    vtkMapper.getResolveCoincidentTopologyLineOffsetParameters();
+  vtkMapper.setResolveCoincidentTopologyLineOffsetParameters(-3, -3);
+  vtkMapper.setResolveCoincidentTopologyLineOffsetParameters(
+    startingLineParameters
+  );
+
+  t.ok('rendering', 'CoincidentTopologyHelper functions called without error');
+
+  // Free memory, end the test
+  gc.releaseResources();
+});