api: Make query_string parameter of make_endpoint_url non-optional

When Some(_), the argument would often be an empty string. By always
using the empty string to mean "no query", we avoid trailing a `?` on
URLs without having two parameter values that mean the same thing.

crates/ruma-client-api/src/push/set_pushrule.rs

@@ -91,7 +91,7 @@ pub mod v3 {
                 considering_versions,
                 base_url,
                 &[&self.scope, &self.rule.kind(), &self.rule.rule_id()],
-                Some(&query_string),
+                &query_string,
             )?;
 
             let body: RequestBody = self.rule.into();

crates/ruma-client-api/src/state/get_state_events_for_key.rs

@@ -88,7 +88,7 @@ pub mod v3 {
                     considering_versions,
                     base_url,
                     &[&self.room_id, &self.event_type, &self.state_key],
-                    None,
+                    "",
                 )?)
                 .header(header::CONTENT_TYPE, "application/json")
                 .header(

crates/ruma-client-api/src/state/send_state_event.rs

@@ -134,7 +134,7 @@ pub mod v3 {
                     considering_versions,
                     base_url,
                     &[&self.room_id, &self.event_type, &self.state_key],
-                    Some(&query_string),
+                    &query_string,
                 )?)
                 .header(header::CONTENT_TYPE, "application/json")
                 .header(
@@ -220,7 +220,7 @@ pub mod v3 {
         };
 
         // This used to panic in make_endpoint_url because of a mismatch in the path parameter count
-        Request::new(
+        let req = Request::new(
             room_id!("!room:server.tld"),
             &EmptyStateKey,
             &RoomNameEventContent::new(Some("Test room".to_owned())),
@@ -232,5 +232,10 @@ pub mod v3 {
             &[MatrixVersion::V1_1],
         )
         .unwrap();
+
+        assert_eq!(
+            req.uri(),
+            "https://server.tld/_matrix/client/v3/rooms/%21room%3Aserver%2Etld/state/m%2Eroom%2Ename/"
+        );
     }
 }

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

@@ -90,7 +90,7 @@ impl Metadata {
         versions: &[MatrixVersion],
         base_url: &str,
         path_args: &[&dyn Display],
-        query_string: Option<&str>,
+        query_string: &str,
     ) -> Result<String, IntoHttpError> {
         let path_with_placeholders = self.history.select_path(versions, self.name)?;
 
@@ -117,9 +117,9 @@ impl Metadata {
             }
         }
 
-        if let Some(query) = query_string {
+        if !query_string.is_empty() {
             res.push('?');
-            res.push_str(query);
+            res.push_str(query_string);
         }
 
         Ok(res)
@@ -699,22 +699,21 @@ mod tests {
     #[test]
     fn make_simple_endpoint_url() {
         let meta = stable_only_metadata(&[(V1_0, "/s")]);
-        let url = meta.make_endpoint_url(&[V1_0], "https://example.org", &[], None).unwrap();
+        let url = meta.make_endpoint_url(&[V1_0], "https://example.org", &[], "").unwrap();
         assert_eq!(url, "https://example.org/s");
     }
 
     #[test]
     fn make_endpoint_url_with_path_args() {
         let meta = stable_only_metadata(&[(V1_0, "/s/:x")]);
-        let url = meta.make_endpoint_url(&[V1_0], "https://example.org", &[&"123"], None).unwrap();
+        let url = meta.make_endpoint_url(&[V1_0], "https://example.org", &[&"123"], "").unwrap();
         assert_eq!(url, "https://example.org/s/123");
     }
 
     #[test]
     fn make_endpoint_url_with_query() {
         let meta = stable_only_metadata(&[(V1_0, "/s/")]);
-        let url =
-            meta.make_endpoint_url(&[V1_0], "https://example.org", &[], Some("foo=bar")).unwrap();
+        let url = meta.make_endpoint_url(&[V1_0], "https://example.org", &[], "foo=bar").unwrap();
         assert_eq!(url, "https://example.org/s/?foo=bar");
     }
 
@@ -722,7 +721,7 @@ mod tests {
     #[should_panic]
     fn make_endpoint_url_wrong_num_path_args() {
         let meta = stable_only_metadata(&[(V1_0, "/s/:x")]);
-        _ = meta.make_endpoint_url(&[V1_0], "https://example.org", &[], None);
+        _ = meta.make_endpoint_url(&[V1_0], "https://example.org", &[], "");
     }
 
     const EMPTY: VersionHistory =

crates/ruma-common/tests/api/manual_endpoint_impl.rs

@@ -51,12 +51,8 @@ impl OutgoingRequest for Request {
         _access_token: SendAccessToken<'_>,
         considering_versions: &'_ [MatrixVersion],
     ) -> Result<http::Request<T>, IntoHttpError> {
-        let url = METADATA.make_endpoint_url(
-            considering_versions,
-            base_url,
-            &[&self.room_alias],
-            None,
-        )?;
+        let url =
+            METADATA.make_endpoint_url(considering_versions, base_url, &[&self.room_alias], "")?;
 
         let request_body = RequestBody { room_id: self.room_id };
 

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

@@ -38,9 +38,7 @@ impl Request {
                 let request_query = RequestQuery(self.#field_name);
                 assert_trait_impl(&request_query.0);
 
-                ::std::option::Option::Some(
                 &#ruma_common::serde::urlencoded::to_string(request_query)?
-                )
             }}
         } else if self.has_query_fields() {
             let request_query_init_fields = struct_init_fields(
@@ -53,12 +51,10 @@ impl Request {
                     #request_query_init_fields
                 };
 
-                ::std::option::Option::Some(
                 &#ruma_common::serde::urlencoded::to_string(request_query)?
-                )
             }}
         } else {
-            quote! { ::std::option::Option::None }
+            quote! { "" }
         };
 
         // If there are no body fields, the request body will be empty (not `{}`), so the