remix-run · jacob-ebey · Mar 24, 2026 · May 8, 2026 · May 12, 2026 · May 14, 2026
diff --git a/.changeset/esm-only-packages.md b/.changeset/esm-only-packages.md
@@ -0,0 +1,15 @@
+---
+"@react-router/architect": major
+"@react-router/cloudflare": major
+"@react-router/dev": major
+"@react-router/express": major
+"@react-router/fs-routes": major
+"@react-router/node": major
+"@react-router/remix-routes-option-adapter": major
+"@react-router/serve": major
+"create-react-router": major
+"react-router": major
+"react-router-dom": major
+---
+
+Switch the published packages in `packages/` to ESM-only.
diff --git a/.nvmrc b/.nvmrc
@@ -1 +1 @@
-22
+24
diff --git a/.prettierignore b/.prettierignore
@@ -1,3 +1,4 @@
+# Prettier ignore patterns.
 /fixtures/
 node_modules/
 pnpm-lock.yaml

diff --git a/docs/prettier.config.js b/docs/prettier.config.js
@@ -1,7 +1,9 @@
 /**
  * @type {import('prettier').Options}
  */
-module.exports = {
-  ...require("../prettier.config"),
+import config from "../prettier.config.js";
+
+export default {
+  ...config,
   printWidth: 60,
 };
diff --git a/integration/helpers/vite.ts b/integration/helpers/vite.ts
@@ -16,7 +16,7 @@ import type { Page } from "@playwright/test";
 import { test as base, expect } from "@playwright/test";
 import type { Config } from "@react-router/dev/config";
 
-const require = createRequire(import.meta.url);
+const nodeRequire = createRequire(import.meta.url);
 
 const reactRouterBin = "node_modules/@react-router/dev/bin.js";
 const __dirname = url.fileURLToPath(new URL(".", import.meta.url));
@@ -354,7 +354,7 @@ export const wranglerPagesDev = async ({
   port: number;
 }) => {
   let nodeBin = process.argv[0];
-  let wranglerBin = require.resolve("wrangler/bin/wrangler.js", {
+  let wranglerBin = nodeRequire.resolve("wrangler/bin/wrangler.js", {
     paths: [cwd],
   });
 

diff --git a/integration/vite-spa-mode-test.ts b/integration/vite-spa-mode-test.ts
@@ -638,7 +638,9 @@ test.describe("SPA Mode", () => {
                         <Links />
                       </head>
                       <body>
-                        {children}
+                        <div data-layout>
+                          {children}
+                        </div>
                         <ScrollRestoration />
                         <Scripts />
                       </body>
@@ -666,7 +668,7 @@ test.describe("SPA Mode", () => {
           expect(html.match(/<html/g)?.length).toBe(1);
           expect(html.match(/<\/html/g)?.length).toBe(1);
           expect(html.match(/window.__reactRouterContext =/g)?.length).toBe(1);
-          expect(html.match(/💿 Hey developer 👋/g)?.length).toBe(1);
+          expect(html).toMatch('<div data-layout="true">');
         });
 
         test("does not inherit single fetch revalidation behavior", async ({

diff --git a/jest/jest.config.shared.js b/jest/jest.config.shared.js
@@ -1,3 +1,5 @@
+import { fileURLToPath } from "node:url";
+
 const ignorePatterns = [
   "\\/build\\/",
   "\\/coverage\\/",
@@ -7,21 +9,20 @@ const ignorePatterns = [
 ];
 
 /** @type {import('jest').Config} */
-module.exports = {
+export default {
   moduleNameMapper: {
     "@react-router/dev$": "<rootDir>/../react-router-dev/index.ts",
     "@react-router/express$": "<rootDir>/../react-router-express/index.ts",
     "@react-router/node$": "<rootDir>/../react-router-node/index.ts",
     "@react-router/serve$": "<rootDir>/../react-router-serve/index.ts",
     "^react-router$": "<rootDir>/../react-router/index.ts",
-    "^@web3-storage/multipart-parser$": require.resolve(
-      "@web3-storage/multipart-parser",
-    ),
   },
   modulePathIgnorePatterns: ignorePatterns,
+  extensionsToTreatAsEsm: [".ts", ".tsx"],
+  setupFiles: [fileURLToPath(new URL("./setup-globals.js", import.meta.url))],
   testMatch: ["<rootDir>/**/*-test.[jt]s?(x)"],
   transform: {
-    "\\.[jt]sx?$": require.resolve("./transform"),
+    "\\.[jt]sx?$": fileURLToPath(new URL("./transform.js", import.meta.url)),
   },
   watchPathIgnorePatterns: [...ignorePatterns, "\\/node_modules\\/"],
   globals: {

diff --git a/jest/setup-globals.js b/jest/setup-globals.js
@@ -0,0 +1,3 @@
+import { jest } from "@jest/globals";
+
+globalThis.jest = jest;
diff --git a/jest/transform.js b/jest/transform.js
@@ -1,25 +1,12 @@
-let { default: babelJest } = require("babel-jest");
+import babelJest from "babel-jest";
 
-/**
- * Replace `import.meta` with `undefined`
- *
- * Needed to support server-side CJS in Jest
- * when `import.meta.hot` is used for HMR.
- */
-let metaPlugin = ({ types: t }) => ({
-  visitor: {
-    MetaProperty: (path) => {
-      path.replaceWith(t.identifier("undefined"));
-    },
-  },
-});
-
-module.exports = babelJest.createTransformer({
+export default babelJest.createTransformer({
   babelrc: false,
+  configFile: false,
   presets: [
-    ["@babel/preset-env", { loose: true }],
+    ["@babel/preset-env", { targets: { node: "current" }, modules: false }],
     "@babel/preset-react",
     "@babel/preset-typescript",
   ],
-  plugins: ["babel-plugin-dev-expression", metaPlugin],
+  plugins: ["babel-plugin-dev-expression"],
 });
diff --git a/package.json b/package.json
@@ -1,6 +1,7 @@
 {
   "name": "@remix-run/react-router",
   "private": true,
+  "type": "module",
   "scripts": {
     "build": "pnpm run --filter=\"./packages/**/*\" build",
     "watch": "pnpm build && pnpm run --filter=\"./packages/**/*\" --parallel build --watch",
@@ -25,8 +26,8 @@
     "pr-preview": "node ./scripts/pr-preview.ts",
     "release-comments": "node scripts/release-comments.ts",
     "setup-installable-branch": "node scripts/setup-installable-branch.ts",
-    "test": "jest",
-    "test:inspect": "node --inspect-brk ./node_modules/.bin/jest",
+    "test": "node --experimental-vm-modules ./node_modules/jest/bin/jest.js",
+    "test:inspect": "node --experimental-vm-modules --inspect-brk ./node_modules/jest/bin/jest.js",
     "typegen": "pnpm run --recursive --parallel typegen",
     "typecheck": "pnpm run --recursive --parallel typecheck",
     "test:integration:run": "pnpm playwright:integration",
@@ -49,8 +50,7 @@
   "resolutions": {
     "@types/react": "catalog:",
     "@types/react-dom": "catalog:",
-    "@types/react-test-renderer": "^18.3.1",
-    "jsdom": "22.1.0"
+    "@types/react-test-renderer": "^18.3.1"
   },
   "dependencies": {
     "@babel/core": "^7.27.7",
@@ -61,14 +61,15 @@
     "@manypkg/get-packages": "^1.1.3",
     "@mdx-js/rollup": "^3.1.0",
     "@playwright/test": "^1.58.2",
-    "@types/jest": "^29.5.4",
+    "@remix-run/changelog-github": "^0.0.5",
+    "@types/jest": "^30.0.0",
     "@types/jsdom": "^21.1.1",
     "@types/react": "catalog:",
     "@types/react-dom": "catalog:",
     "@types/react-test-renderer": "^19.0.0",
     "@typescript-eslint/eslint-plugin": "^8.57.1",
     "@typescript-eslint/parser": "^8.57.1",
-    "babel-jest": "^29.7.0",
+    "babel-jest": "^30.3.0",
     "babel-plugin-dev-expression": "^0.2.3",
     "dox": "^1.0.0",
     "eslint": "^10.0.3",
@@ -82,7 +83,9 @@
     "eslint-plugin-react-hooks": "next",
     "fast-glob": "3.2.11",
     "isbot": "^5.1.11",
-    "jest": "^29.6.4",
+    "jest": "^30.3.0",
+    "jest-environment-jsdom": "^29.6.2",
+    "jsdom": "^29.0.0",
     "jsonfile": "^6.1.0",
     "picocolors": "^1.1.1",
     "prettier": "^3.6.2",
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		import { jest } from "@jest/globals";

		globalThis.jest = jest;