api: Remove method from Request derive attributes

crates/ruma-common/src/api/metadata.rs

@@ -3,6 +3,7 @@ use std::{
     str::FromStr,
 };
 
+use bytes::BufMut;
 use http::Method;
 use percent_encoding::utf8_percent_encode;
 use tracing::warn;
@@ -11,7 +12,7 @@ use super::{
     error::{IntoHttpError, UnknownVersionError},
     AuthScheme,
 };
-use crate::RoomVersionId;
+use crate::{serde::slice_to_buf, RoomVersionId};
 
 /// Metadata about an API endpoint.
 #[derive(Clone, Debug)]
@@ -37,6 +38,21 @@ pub struct Metadata {
 }
 
 impl Metadata {
+    /// Returns an empty request body for this Matrix request.
+    ///
+    /// For `GET` requests, it returns an entirely empty buffer, for others it returns an empty JSON
+    /// object (`{}`).
+    pub fn empty_request_body<B>(&self) -> B
+    where
+        B: Default + BufMut,
+    {
+        if self.method == Method::GET {
+            Default::default()
+        } else {
+            slice_to_buf(b"{}")
+        }
+    }
+
     /// Generate the endpoint URL for this endpoint.
     pub fn make_endpoint_url(
         &self,

crates/ruma-macros/src/api/api_request.rs

@@ -82,7 +82,6 @@ impl Request {
         );
         let struct_attributes = &self.attributes;
 
-        let method = &metadata.method;
         let authentication = &metadata.authentication;
 
         let request_ident = Ident::new("Request", self.request_kw.span());
@@ -101,11 +100,7 @@ impl Request {
             )]
             #[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
             #[incoming_derive(!Deserialize, #ruma_macros::_FakeDeriveRumaApi)]
-            #[ruma_api(
+            #[ruma_api(authentication = #authentication, error_ty = #error_ty)]
-                method = #method,
-                authentication = #authentication,
-                error_ty = #error_ty,
-            )]
             #( #struct_attributes )*
             pub struct #request_ident < #(#lifetimes),* > {
                 #fields

crates/ruma-macros/src/api/attribute.rs

@@ -13,7 +13,6 @@ mod kw {
     syn::custom_keyword!(query_map);
     syn::custom_keyword!(header);
     syn::custom_keyword!(authentication);
-    syn::custom_keyword!(method);
     syn::custom_keyword!(error_ty);
     syn::custom_keyword!(manual_body_serde);
 }
@@ -57,7 +56,6 @@ impl Parse for RequestMeta {
 
 pub enum DeriveRequestMeta {
     Authentication(Type),
-    Method(Type),
     ErrorTy(Type),
 }
 
@@ -68,10 +66,6 @@ impl Parse for DeriveRequestMeta {
             let _: kw::authentication = input.parse()?;
             let _: Token![=] = input.parse()?;
             input.parse().map(Self::Authentication)
-        } else if lookahead.peek(kw::method) {
-            let _: kw::method = input.parse()?;
-            let _: Token![=] = input.parse()?;
-            input.parse().map(Self::Method)
         } else if lookahead.peek(kw::error_ty) {
             let _: kw::error_ty = input.parse()?;
             let _: Token![=] = input.parse()?;

crates/ruma-macros/src/api/request.rs

@@ -48,7 +48,6 @@ pub fn expand_derive_request(input: DeriveInput) -> syn::Result<TokenStream> {
 
     let mut authentication = None;
     let mut error_ty = None;
-    let mut method = None;
 
     for attr in input.attrs {
         if !attr.path.is_ident("ruma_api") {
@@ -60,7 +59,6 @@ pub fn expand_derive_request(input: DeriveInput) -> syn::Result<TokenStream> {
         for meta in metas {
             match meta {
                 DeriveRequestMeta::Authentication(t) => authentication = Some(parse_quote!(#t)),
-                DeriveRequestMeta::Method(t) => method = Some(parse_quote!(#t)),
                 DeriveRequestMeta::ErrorTy(t) => error_ty = Some(t),
             }
         }
@@ -72,12 +70,17 @@ pub fn expand_derive_request(input: DeriveInput) -> syn::Result<TokenStream> {
         fields,
         lifetimes,
         authentication: authentication.expect("missing authentication attribute"),
-        method: method.expect("missing method attribute"),
         error_ty: error_ty.expect("missing error_ty attribute"),
     };
 
-    request.check()?;
+    let ruma_common = import_ruma_common();
-    Ok(request.expand_all())
+    let test = request.check(&ruma_common)?;
+    let types_impls = request.expand_all(&ruma_common);
+
+    Ok(quote! {
+        #types_impls
+        #test
+    })
 }
 
 #[derive(Default)]
@@ -95,7 +98,6 @@ struct Request {
     fields: Vec<RequestField>,
 
     authentication: AuthScheme,
-    method: Ident,
     error_ty: Type,
 }
 
@@ -149,8 +151,7 @@ impl Request {
         self.fields.iter().find_map(RequestField::as_query_map_field)
     }
 
-    fn expand_all(&self) -> TokenStream {
+    fn expand_all(&self, ruma_common: &TokenStream) -> TokenStream {
-        let ruma_common = import_ruma_common();
         let ruma_macros = quote! { #ruma_common::exports::ruma_macros };
         let serde = quote! { #ruma_common::exports::serde };
 
@@ -206,8 +207,8 @@ impl Request {
             }
         });
 
-        let outgoing_request_impl = self.expand_outgoing(&ruma_common);
+        let outgoing_request_impl = self.expand_outgoing(ruma_common);
-        let incoming_request_impl = self.expand_incoming(&ruma_common);
+        let incoming_request_impl = self.expand_incoming(ruma_common);
 
         quote! {
             #request_body_struct
@@ -218,7 +219,9 @@ impl Request {
         }
     }
 
-    pub(super) fn check(&self) -> syn::Result<()> {
+    pub(super) fn check(&self, ruma_common: &TokenStream) -> syn::Result<Option<TokenStream>> {
+        let http = quote! { #ruma_common::exports::http };
+
         // TODO: highlight problematic fields
 
         let newtype_body_fields = self.fields.iter().filter(|f| {
@@ -275,14 +278,17 @@ impl Request {
             ));
         }
 
-        if self.method == "GET" && (has_body_fields || has_newtype_body_field) {
+        Ok((has_body_fields || has_newtype_body_field).then(|| {
-            return Err(syn::Error::new_spanned(
+            quote! {
-                &self.ident,
+                #[::std::prelude::v1::test]
+                fn request_is_not_get() {
+                    ::std::assert_ne!(
+                        METADATA.method, #http::Method::GET,
                         "GET endpoints can't have body fields",
-            ));
+                    );
                 }
-
+            }
-        Ok(())
+        }))
     }
 }
 

crates/ruma-macros/src/api/request/incoming.rs

@@ -11,7 +11,6 @@ impl Request {
         let serde = quote! { #ruma_common::exports::serde };
         let serde_json = quote! { #ruma_common::exports::serde_json };
 
-        let method = &self.method;
         let error_ty = &self.error_ty;
 
         let incoming_request_type = if self.has_lifetimes() {
@@ -203,9 +202,9 @@ impl Request {
                     B: ::std::convert::AsRef<[::std::primitive::u8]>,
                     S: ::std::convert::AsRef<::std::primitive::str>,
                 {
-                    if request.method() != #http::Method::#method {
+                    if request.method() != METADATA.method {
                         return Err(#ruma_common::api::error::FromHttpRequestError::MethodMismatch {
-                            expected: #http::Method::#method,
+                            expected: METADATA.method,
                             received: request.method().clone(),
                         });
                     }

crates/ruma-macros/src/api/request/outgoing.rs

@@ -10,7 +10,6 @@ impl Request {
         let bytes = quote! { #ruma_common::exports::bytes };
         let http = quote! { #ruma_common::exports::http };
 
-        let method = &self.method;
         let error_ty = &self.error_ty;
 
         let path_fields =
@@ -137,10 +136,8 @@ impl Request {
             quote! {
                 #ruma_common::serde::json_to_buf(&RequestBody { #initializers })?
             }
-        } else if method == "GET" {
-            quote! { <T as ::std::default::Default>::default() }
         } else {
-            quote! { #ruma_common::serde::slice_to_buf(b"{}") }
+            quote! { METADATA.empty_request_body::<T>() }
         };
 
         let (impl_generics, ty_generics, where_clause) = self.generics.split_for_impl();
@@ -170,7 +167,7 @@ impl Request {
                     considering_versions: &'_ [#ruma_common::api::MatrixVersion],
                 ) -> ::std::result::Result<#http::Request<T>, #ruma_common::api::error::IntoHttpError> {
                     let mut req_builder = #http::Request::builder()
-                        .method(#http::Method::#method)
+                        .method(METADATA.method)
                         .uri(METADATA.make_endpoint_url(
                             considering_versions,
                             base_url,