fix: Only permit web workers to be initialized once. (#1535)

platform/viewer/src/utils/initWebWorkers.js

@@ -1,6 +1,8 @@
 import cornerstoneWADOImageLoader from 'cornerstone-wado-image-loader';
 
-export default function initWebWorkers() {  
+let initialized = false;
+
+export default function initWebWorkers() {
   const config = {
     maxWebWorkers: Math.max(navigator.hardwareConcurrency - 1, 1),
     startWebWorkersOnDemand: true,
@@ -13,5 +15,8 @@ export default function initWebWorkers() {
     },
   };
 
-  cornerstoneWADOImageLoader.webWorkerManager.initialize(config);
+  if (!initialized) {
+    cornerstoneWADOImageLoader.webWorkerManager.initialize(config);
+    initialized = true;
+  }
 }

platform/viewer/src/utils/initWebWorkers.test.js

@@ -10,3 +10,14 @@ describe('initWebWorkers', () => {
     ).toHaveBeenCalled();
   });
 });
+
+describe('initWebWorkers', () => {
+  it("initializes cornerstoneWADOImageLoader's web workers only once", () => {
+    initWebWorkers();
+    initWebWorkers();
+
+    expect(
+      cornerstoneWADOImageLoader.webWorkerManager.initialize
+    ).toHaveBeenCalledTimes(1);
+  });
+});