Feat: parse shuttle::endpoint macro (#490)

* feat: parse params

* feat: parse app

* feat: add test for missing endpoint attribute

* test: invalid args, params and syntax

* feat: check for and test no params

* feat: don't emit error for missing annotation

this way users can create separate functions for their endpoint logic

* fix: remove missing attribute error, not param

* refactor: reword comment

Co-authored-by: Pieter <pieter@chesedo.me>

* feat: duplicate param test, address review

* feat: only strip endpoint attributes

* feat: check for extra endpoint attributes

* refactor: clearer error span for extra endpoints

* feat: has_err variable to group param errors

* refactor: remove optional hint

Co-authored-by: Pieter <pieter@chesedo.me>

* docs: add TODO for multiple endpoint attributes

Co-authored-by: Pieter <pieter@chesedo.me>

codegen/src/lib.rs

@@ -1,11 +1,27 @@
 mod main;
 mod next;
 
+use next::App;
 use proc_macro::TokenStream;
 use proc_macro_error::proc_macro_error;
+use syn::{parse_macro_input, File};
 
 #[proc_macro_error]
 #[proc_macro_attribute]
 pub fn main(attr: TokenStream, item: TokenStream) -> TokenStream {
     main::r#impl(attr, item)
 }
+
+#[proc_macro_error]
+#[proc_macro]
+pub fn app(item: TokenStream) -> TokenStream {
+    let mut file = parse_macro_input!(item as File);
+
+    let app = App::from_file(&mut file);
+
+    quote::quote!(
+        #file
+        #app
+    )
+    .into()
+}

codegen/src/main/mod.rs

@@ -652,6 +652,6 @@ mod tests {
     #[test]
     fn ui() {
         let t = trybuild::TestCases::new();
-        t.compile_fail("tests/ui/*.rs");
+        t.compile_fail("tests/ui/main/*.rs");
     }
 }