From d70c8a46919dfd5f051c04607063749d7891bbee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EA=B9=80=EC=98=81=ED=9B=88?= <joseph0926@naver.com>
Date: Mon, 1 Sep 2025 10:21:45 +0900
Subject: [PATCH] fix: handle parameters with static suffixes in generatePath

---
 contributors.yml                              |  1 +
 .../__tests__/generatePath-test.tsx           | 21 +++++++++++++++++++
 packages/react-router/lib/router/utils.ts     |  6 +++---
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/contributors.yml b/contributors.yml
index e6c663f7be..06bcb5c118 100644
--- a/contributors.yml
+++ b/contributors.yml
@@ -187,6 +187,7 @@
 - jmjpro
 - johnpangalos
 - jonkoops
+- joseph0926
 - jrakotoharisoa
 - jrestall
 - juanpprieto
diff --git a/packages/react-router/__tests__/generatePath-test.tsx b/packages/react-router/__tests__/generatePath-test.tsx
index c4fbf35b7b..3bf3a18433 100644
--- a/packages/react-router/__tests__/generatePath-test.tsx
+++ b/packages/react-router/__tests__/generatePath-test.tsx
@@ -191,4 +191,25 @@ describe("generatePath", () => {
 
     consoleWarn.mockRestore();
   });
+
+  describe("with params followed by static text", () => {
+    it("interpolates params with file extensions", () => {
+      expect(generatePath("/books/:id.json", { id: "42" })).toBe(
+        "/books/42.json",
+      );
+      expect(generatePath("/api/:resource.xml", { resource: "users" })).toBe(
+        "/api/users.xml",
+      );
+      expect(generatePath("/:lang.html", { lang: "en" })).toBe("/en.html");
+    });
+
+    it("handles multiple extensions", () => {
+      expect(generatePath("/files/:name.tar.gz", { name: "archive" })).toBe(
+        "/files/archive.tar.gz",
+      );
+      expect(generatePath("/:file.min.js", { file: "app" })).toBe(
+        "/app.min.js",
+      );
+    });
+  });
 });
diff --git a/packages/react-router/lib/router/utils.ts b/packages/react-router/lib/router/utils.ts
index 14e5e40c51..cd60e83e85 100644
--- a/packages/react-router/lib/router/utils.ts
+++ b/packages/react-router/lib/router/utils.ts
@@ -1301,12 +1301,12 @@ export function generatePath<Path extends string>(
         return stringify(params[star]);
       }
 
-      const keyMatch = segment.match(/^:([\w-]+)(\??)$/);
+      const keyMatch = segment.match(/^:([\w-]+)(\??)(.*)/);
       if (keyMatch) {
-        const [, key, optional] = keyMatch;
+        const [, key, optional, suffix] = keyMatch;
         let param = params[key as PathParam<Path>];
         invariant(optional === "?" || param != null, `Missing ":${key}" param`);
-        return encodeURIComponent(stringify(param));
+        return encodeURIComponent(stringify(param)) + suffix;
       }
 
       // Remove any optional markers from optional static segments