Fix encoded # in path parameter causes route to be evaluated differently

contributors.yml

@@ -309,3 +309,4 @@
 - yuleicul
 - zeromask1337
 - zheng-chuang
+- dunnai

packages/react-router/__tests__/dom/navigate-encode-params-test.tsx

@@ -93,4 +93,44 @@ describe("navigate with params", () => {
       expect(node.innerHTML).toMatch(/react\+router/);
     });
   });
+
+  describe("when navigate params are encoded using #", () => {
+    it("the encoding of the # parameter in the URL has been changed", () => {
+      function Start() {
+        let navigate = useNavigate();
+
+        React.useEffect(() => {
+          navigate("/route/react%23router/subroute/router/blog");
+        });
+
+        return null;
+      }
+
+      function Blog() {
+        let params = useParams();
+        return <h1>Blog: {params.routeName}-{params.subrouteName}</h1>;
+      }
+
+      act(() => {
+        ReactDOM.createRoot(node).render(
+          <BrowserRouter>
+            <Routes>
+              <Route path="/" element={<Start />} />
+              <Route path="/route/:routeName/subroute/:subrouteName/*" element={
+                <Routes>
+                  <Route path="blog" element={<Blog />} />
+                  <Route path="*" element={null} />
+                </Routes>
+              } />
+            </Routes>
+          </BrowserRouter>
+        );
+      });
+
+      let pathname = window.location.pathname;
+      expect(pathname).toEqual("/route/react%23router/subroute/router/blog");
+
+      expect(node.innerHTML).toMatch(/react#router-router/);
+    });
+  });
 });

packages/react-router/lib/router/history.ts

@@ -695,6 +695,7 @@ function getUrlBasedHistory(
     // pre-encode them since they might be part of a matching splat param from
     // an ancestor route
     href = href.replace(/ $/, "%20");
+    href = typeof to === "string" ? href.replace(/#/, "%23") : href
     invariant(
       base,
       `No window.location.(origin|href) available to create URL for href: ${href}`