Switch the default server function codec to json (#3602)

* Switch the default server function codec to json

* test both input and output encoding

packages/playwright-tests/fullstack/src/main.rs

@@ -41,6 +41,7 @@ fn app() -> Element {
             Errors {}
         }
         OnMounted {}
+        DefaultServerFnCodec {}
         DocumentElements {}
     }
 }
@@ -59,6 +60,15 @@ fn OnMounted() -> Element {
     }
 }
 
+#[component]
+fn DefaultServerFnCodec() -> Element {
+    let resource = use_server_future(|| get_server_data_empty_vec(Vec::new()))?;
+    let empty_vec = resource.unwrap().unwrap();
+    assert!(empty_vec.is_empty());
+
+    rsx! {}
+}
+
 #[cfg(feature = "server")]
 async fn assert_server_context_provided() {
     let FromContext(i): FromContext<u32> = extract().await.unwrap();
@@ -79,6 +89,15 @@ async fn get_server_data() -> Result<String, ServerFnError> {
     Ok("Hello from the server!".to_string())
 }
 
+// Make sure the default codec work with empty data structures
+// Regression test for https://github.com/DioxusLabs/dioxus/issues/2628
+#[server]
+async fn get_server_data_empty_vec(empty_vec: Vec<String>) -> Result<Vec<String>, ServerFnError> {
+    assert_server_context_provided().await;
+    assert!(empty_vec.is_empty());
+    Ok(Vec::new())
+}
+
 #[server]
 async fn server_error() -> Result<String, ServerFnError> {
     assert_server_context_provided().await;