feat(react-router): don't bundle react-router in react-router/dom export

.changeset/breezy-pets-hug.md

@@ -0,0 +1,5 @@
+---
+"react-router": patch
+---
+
+Don't bundle `react-router` in `react-router/dom` CJS export

packages/react-router/__tests__/dom/dom-export-test.tsx

@@ -0,0 +1,40 @@
+import * as React from "react";
+
+import { render, screen } from "@testing-library/react";
+import { createMemoryRouter, useParams } from "react-router";
+import { RouterProvider } from "react-router/dom";
+
+describe("react-router/dom", () => {
+  function ShowParams() {
+    return <pre data-testid="params">{JSON.stringify(useParams())}</pre>;
+  }
+
+  describe("Does not bundle react-router causing duplicate context issues", () => {
+    it("with route provider shows the url params", async () => {
+      const router = createMemoryRouter(
+        [
+          {
+            path: "/blog/:slug",
+            element: <ShowParams />,
+          },
+        ],
+        {
+          initialEntries: ["/blog/react-router"],
+        }
+      );
+
+      // When react-router was bundled in CJS scenarios, this `react-router/dom`
+      // version of `RouterProvider` caused duplicate contexts and we would not
+      // find the param values
+      render(<RouterProvider router={router} />);
+
+      expect(await screen.findByTestId("params")).toMatchInlineSnapshot(`
+      <pre
+        data-testid="params"
+      >
+        {"slug":"react-router"}
+      </pre>
+    `);
+    });
+  });
+});

packages/react-router/tsup.config.ts

@@ -13,6 +13,8 @@ const config = (enableDevWarnings: boolean) =>
       clean: false,
       entry,
       format: ["cjs"],
+      // Don't bundle `react-router` in sub-exports (i.e., `react-router/dom`)
+      external: ["react-router"],
       outDir: enableDevWarnings ? "dist/development" : "dist/production",
       dts: true,
       banner: {
@@ -28,6 +30,10 @@ const config = (enableDevWarnings: boolean) =>
       clean: false,
       entry,
       format: ["esm"],
+      // We don't do the external thing for `react-router` here because it
+      // doesn't get bundled by default in the ESM build, and when we tried it
+      // in https://github.com/remix-run/react-router/pull/13497 it changed up
+      // some chunk creation that we didn't want to risk having any side effects
       outDir: enableDevWarnings ? "dist/development" : "dist/production",
       dts: true,
       banner: {