[FIX] router: preserve pathname in hash mode

closes #397

tests/router/router.test.ts

@@ -52,6 +52,15 @@ describe("router miscellaneous", () => {
     expect(window.location.hash).toBe("#/users/5");
     expect(env.qweb.forceUpdate).toHaveBeenCalledTimes(2);
   });
+
+  test("navigate in hash mode preserve location", async () => {
+    router = new TestRouter(env, [{ name: "users", path: "/users/{{id}}" }], {mode: "hash"});
+    window.history.pushState({}, "title", window.location.origin + '/test.html');
+    expect(window.location.href).toBe("http://localhost/test.html");
+    await router.navigate({ to: "users", params: { id: 3 } });
+    expect(window.location.href).toBe("http://localhost/test.html#/users/3");
+  });
+
 });
 
 describe("routeToPath", () => {