util: introduce new temp error with unset error code

packages/util/src/errors.ts

@@ -13,6 +13,11 @@ export type EthereumJSErrorObject = {
   type: EthereumJSErrorMetaData
 }
 
+// In order to update all our errors to use `EthereumJSError`, temporarily include the
+// unset error code. All errors throwing this code should be updated to use the relevant
+// error code.
+export const UNSET_ERROR_CODE = 'ETHEREUMJS_UNSET_ERROR_CODE'
+
 /**
  * Generic EthereumJS error with attached metadata
  */
@@ -41,6 +46,18 @@ export class EthereumJSError<T extends { code: string }> extends Error {
   }
 }
 
+/**
+ * @deprecated Use `EthereumJSError` with a set error code instead
+ * @param message Optional error message
+ * @param stack Optional stack trace
+ * @returns
+ */
+export function EthereumJSErrorUnsetCode(message?: string, stack?: string) {
+  return new EthereumJSError({ code: UNSET_ERROR_CODE }, message, stack)
+}
+
+// Below here: specific monorepo-wide errors
+
 export enum UsageErrorType {
   UNSUPPORTED_FEATURE = 'unsupported feature',
 }