fix(i/o): chain loadData promise in 3 readers instead of branching prevents unhandled rejection

#3437

Author: skoloCFD

Sources/IO/Geometry/PLYReader/index.js

@@ -627,11 +627,8 @@ function vtkPLYReader(publicAPI, model) {
   };
 
   // Fetch the actual data arrays
-  publicAPI.loadData = (option = {}) => {
-    const promise = fetchData(model.url, option);
-    promise.then(publicAPI.parse);
-    return promise;
-  };
+  publicAPI.loadData = (option = {}) =>
+    fetchData(model.url, option).then(publicAPI.parse);
 
   publicAPI.parse = (content) => {
     if (typeof content === 'string') {

Sources/IO/Geometry/STLReader/index.js

@@ -240,11 +240,8 @@ function vtkSTLReader(publicAPI, model) {
   };
 
   // Fetch the actual data arrays
-  publicAPI.loadData = (option = {}) => {
-    const promise = fetchData(model.url, option);
-    promise.then(publicAPI.parse);
-    return promise;
-  };
+  publicAPI.loadData = (option = {}) =>
+    fetchData(model.url, option).then(publicAPI.parse);
 
   publicAPI.parse = (content) => {
     if (typeof content === 'string') {

Sources/IO/Legacy/PolyDataReader/index.js

@@ -46,11 +46,8 @@ function vtkPolyDataReader(publicAPI, model) {
   };
 
   // Fetch the actual data arrays
-  publicAPI.loadData = (option = {}) => {
-    const promise = fetchData(model.url, option);
-    promise.then(publicAPI.parseAsText);
-    return promise;
-  };
+  publicAPI.loadData = (option = {}) =>
+    fetchData(model.url, option).then(publicAPI.parseAsText);
 
   publicAPI.parseAsText = (content) => {
     if (!content) {