Use assertReturn to cleanup (#2804)

* Use assertReturn to cleanup

* Remove Uint/Int duplication

* Adjust

* ws errors, part 2

* .

* Adj. manual

* adj

* switchMap

* Revert "switchMap"

This reverts commit edfa4a2258f09042b61a27fd3812f0c53039fe4f.

* Revert.

* Revert.

* protected constructor

* Correct isHexJson flag

* Remove isHexJson (always detect)

* Adjust

* Flags

packages/rpc-provider/src/ws/errors.ts

@@ -22,20 +22,22 @@ const known: Record<number, string> = {
   1015: 'TLS Handshake'
 };
 
+function getUnmapped (code: number): string | void {
+  if (code <= 1999) {
+    return '(For WebSocket standard)';
+  } else if (code <= 2999) {
+    return '(For WebSocket extensions)';
+  } else if (code <= 3999) {
+    return '(For libraries and frameworks)';
+  } else if (code <= 4999) {
+    return '(For applications)';
+  }
+}
+
 export function getWSErrorString (code: number): string {
   if (code >= 0 && code <= 999) {
     return '(Unused)';
-  } else if (code >= 1016) {
-    if (code <= 1999) {
-      return '(For WebSocket standard)';
-    } else if (code <= 2999) {
-      return '(For WebSocket extensions)';
-    } else if (code <= 3999) {
-      return '(For libraries and frameworks)';
-    } else if (code <= 4999) {
-      return '(For applications)';
-    }
   }
 
-  return known[code] || '(Unknown)';
+  return known[code] || getUnmapped(code) || '(Unknown)';
 }