feat: add errorMsg object to create an ErrorMessage

Author: atheck

src/ElmUtilities.ts

@@ -40,4 +40,8 @@ export type UpdateMap<TProps, TModel, TMsg extends MessageBase> = {
 export interface ErrorMessage {
     name: "error",
     error: Error,
-}
+}
+
+export const errorMsg = {
+    error: (error: Error): ErrorMessage => ({ name: "error", error }),
+};