From 68ce5dfe3af7d3f689875aaf5566c4f43b7917f3 Mon Sep 17 00:00:00 2001
From: Ulisses Ferreira <ulisses@hey.com>
Date: Thu, 27 Aug 2026 10:25:14 +0100
Subject: [PATCH] chore: ban TypeScript enums via lint rule and convert enum in
 create-package script

Add an ESLint no-restricted-syntax rule banning TSEnumDeclaration, and
convert the MonorepoFiles and Placeholders enums in scripts/create-package
to as const objects with derived union types.
---
 eslint.config.mjs                   |  5 +++++
 scripts/create-package/constants.ts | 28 ++++++++++++++++------------
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/eslint.config.mjs b/eslint.config.mjs
index 2ecded431..81f39389a 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -161,6 +161,11 @@ const config = createConfig([
           typescript,
         ]),
         ...NO_CONTROLLER_STATE_CHANGE_SELECTOR_OBJECTS,
+        {
+          selector: 'TSEnumDeclaration',
+          message:
+            "Don't use enums. There are a number of reasons why they are problematic, but the most important is that TypeScript treats them nominally, not structurally, and this can cause unexpected breaking changes. Instead, use an object + type, an array + type, or just a type. Learn more here: https://github.com/MetaMask/eslint-config/issues/417",
+        },
       ],
     },
   },
diff --git a/scripts/create-package/constants.ts b/scripts/create-package/constants.ts
index cf8992ee0..dcf79cfc0 100644
--- a/scripts/create-package/constants.ts
+++ b/scripts/create-package/constants.ts
@@ -1,20 +1,24 @@
 /**
  * The monorepo files that need to be parsed or modified.
  */
-export enum MonorepoFiles {
-  PackageJson = 'package.json',
-  TsConfig = 'tsconfig.json',
-  TsConfigBuild = 'tsconfig.build.json',
-}
+export const MonorepoFiles = {
+  PackageJson: 'package.json',
+  TsConfig: 'tsconfig.json',
+  TsConfigBuild: 'tsconfig.build.json',
+} as const;
+
+export type MonorepoFiles = (typeof MonorepoFiles)[keyof typeof MonorepoFiles];
 
 /**
  * Placeholder values in package template files that need to be replaced with
  * actual values corresponding to the new package.
  */
-export enum Placeholders {
-  CurrentYear = 'CURRENT_YEAR',
-  NodeVersions = 'NODE_VERSIONS',
-  PackageName = 'PACKAGE_NAME',
-  PackageDescription = 'PACKAGE_DESCRIPTION',
-  PackageDirectoryName = 'PACKAGE_DIRECTORY_NAME',
-}
+export const Placeholders = {
+  CurrentYear: 'CURRENT_YEAR',
+  NodeVersions: 'NODE_VERSIONS',
+  PackageName: 'PACKAGE_NAME',
+  PackageDescription: 'PACKAGE_DESCRIPTION',
+  PackageDirectoryName: 'PACKAGE_DIRECTORY_NAME',
+} as const;
+
+export type Placeholders = (typeof Placeholders)[keyof typeof Placeholders];