Fix

package.json

@@ -1,6 +1,7 @@
 {
   "name": "scratch-blocks",
   "version": "1.1.206",
+  "type": "module",
   "description": "Scratch Blocks is a library for building creative computing interfaces.",
   "author": "Massachusetts Institute of Technology",
   "license": "Apache-2.0",

src/global-patches.ts

@@ -70,8 +70,7 @@ export const goog = {
           elem.className = attrs.join(' ')
         } else {
           for (const key in attrs) {
-            // @ts-ignore
-            elem[key] = attrs[key]
+            elem.setAttribute(key, attrs[key])
           }
         }
       }

tsconfig.json

@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "target": "ESNext",
+    "module": "ESNext",
+    "lib": ["ESNext", "WebWorker", "DOM"],
+    "rootDir": "./src",
+    "strict": true,
+    "noEmit": true,
+    "checkJs": true,
+    "moduleResolution": "Bundler",
+    "allowImportingTsExtensions": true,
+    "resolveJsonModule": true,
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules"],
+  "compileOnSave": false
+}