fixed macro and made take response type attr optionally

src/lib.rs

@@ -3,17 +3,37 @@ use quote::quote;
 use syn::{parse_macro_input, Lit, ItemEnum, DeriveInput, Fields, Data};
 use quote::format_ident;
 
-#[proc_macro_derive(HttpRequest, attributes(http_get))]
+#[proc_macro_derive(HttpRequest, attributes(http_get, http_response))]
 pub fn derive_http_get_request(input: TokenStream) -> TokenStream {
     let input = parse_macro_input!(input as DeriveInput);
     let query_name = &input.ident;
     let query_name_str = query_name.to_string();
 
-    // Derive response enum name by replacing "Q" suffix with "R"
+    // Parse optional #[http_response = "..."] attribute via parse_nested_meta
-    let response_name_str = if query_name_str.ends_with("Q") {
+    let mut response_name_opt: Option<String> = None;
-        query_name_str.trim_end_matches("Q").to_string() + "R"
+    for attr in &input.attrs {
+        if attr.path().is_ident("http_response") {
+            attr.parse_nested_meta(|meta| {
+                if meta.path.is_ident("http_response") {
+                    let lit: Lit = meta.value()?.parse()?;
+                    if let Lit::Str(litstr) = lit {
+                        response_name_opt = Some(litstr.value());
+                    }
+                }
+                Ok(())
+            }).unwrap_or_else(|e| panic!("Error parsing http_response attribute: {}", e));
+        }
+    }
+
+    // Determine response type name
+    let response_name_str = if let Some(custom_resp) = response_name_opt {
+        custom_resp
+    } else if query_name_str == "Q" {
+        "R".to_string()
+    } else if query_name_str.ends_with('Q') {
+        format!("{}R", &query_name_str[..query_name_str.len() - 1])
     } else {
-        panic!("HttpRequest derive macro expects the struct name to end with 'Q'");
+        panic!("HttpRequest derive macro expects the type name to be 'Q' or end with 'Q', or specify #[http_response = \"...\"] to override");
     };
     let response_name = format_ident!("{}", response_name_str);
 
@@ -23,19 +43,19 @@ pub fn derive_http_get_request(input: TokenStream) -> TokenStream {
         if attr.path().is_ident("http_get") {
             attr.parse_nested_meta(|meta| {
                 if meta.path.is_ident("url") {
-                    let value: Lit = meta.value()?.parse()?;
+                    let lit: Lit = meta.value()?.parse()?;
-                    if let Lit::Str(litstr) = value {
+                    if let Lit::Str(litstr) = lit {
                         base_url = Some(litstr.value());
                     }
                 }
                 Ok(())
-            }).unwrap();
+            }).unwrap_or_else(|e| panic!("Error parsing http_get attribute: {}", e));
         }
     }
     let base_url = base_url.expect("Missing #[http_get(url = \"...\")] attribute");
     let base_url_lit = syn::LitStr::new(&base_url, proc_macro2::Span::call_site());
 
-    // Collect query parameters from fields named "lnk_p_*"
+    // Collect query parameters from fields named "lnk_p_*" (only for structs)
     let query_param_code = if let Data::Struct(data_struct) = &input.data {
         if let Fields::Named(fields_named) = &data_struct.fields {
             fields_named.named.iter().filter_map(|field| {
@@ -57,7 +77,6 @@ pub fn derive_http_get_request(input: TokenStream) -> TokenStream {
         Vec::new()
     };
 
-    // Generate the impl
     let expanded = quote! {
         #[async_trait::async_trait]
         impl Queryable for #query_name {
@@ -75,10 +94,15 @@ pub fn derive_http_get_request(input: TokenStream) -> TokenStream {
 
                 let mut url = #base_url_lit.to_string();
                 if !query_params.is_empty() {
-                    let query_string: String = query_params.iter()
+                    let mut query_string = String::new();
-                        .map(|(k, v)| format!("{}={}", k, encode(v)))
+                    let mut first = true;
-                        .collect::<Vec<_>>()
+                    for (k, v) in &query_params {
-                        .join("&");
+                        if !first {
+                            query_string.push('&');
+                        }
+                        first = false;
+                        query_string.push_str(&format!("{}={}", k, encode(v)));
+                    }
                     url.push('?');
                     url.push_str(&query_string);
                 }
@@ -95,7 +119,6 @@ pub fn derive_http_get_request(input: TokenStream) -> TokenStream {
                 let response = request.send().await?;
                 let bytes = response.body().await?;
 
-                // Deserialize into associated R type
                 let parsed: Self::R = serde_json::from_slice(&bytes)?;
                 Ok(parsed)
             }