account for functions that have weird names (usually webpack imports)

src/utils/function-name.ts

@@ -8,9 +8,19 @@ export const functionName = (fn: Function): string => {
   if (name == null || name.length === 0) {
     const match = extract(fn.toString());
     if (match != null && match.length > 1) {
-      return match[1];
+      name = match[1];
     }
-    return 'anonymous';
   }
+
+  name = name.replace(/[^\w]/gi, '')
+
+  if (typeof name != 'string' || name == '') {
+    name = 'anonymous';
+  }
+
+  if (!isNaN(parseInt(name[0]))) {
+    name = '__num_' + name[0];
+  }
+
   return name;
 };