From e48e6dfe67ffff75d8e89723ebbe8c443a1e78e8 Mon Sep 17 00:00:00 2001
From: Tim Kuehn <tikue@google.com>
Date: Tue, 30 Jul 2019 21:31:22 -0700
Subject: [PATCH] Add nice error message for ident collisions

---
 plugins/src/lib.rs | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/plugins/src/lib.rs b/plugins/src/lib.rs
index 96db027..5ea9180 100644
--- a/plugins/src/lib.rs
+++ b/plugins/src/lib.rs
@@ -46,10 +46,24 @@ impl Parse for Service {
         let ident = input.parse()?;
         let content;
         braced!(content in input);
-        let mut rpcs = Vec::new();
+        let mut rpcs = Vec::<RpcMethod>::new();
         while !content.is_empty() {
             rpcs.push(content.parse()?);
         }
+        for rpc in &rpcs {
+            if rpc.ident == "new" {
+                return Err(syn::Error::new(
+                    rpc.ident.span(),
+                    format!("method name conflicts with generated fn `{}Client::new`", ident)
+                ))
+            }
+            if rpc.ident == "serve" {
+                return Err(syn::Error::new(
+                    rpc.ident.span(),
+                    format!("method name conflicts with generated fn `{}::serve`", ident)
+                ))
+            }
+        }
         Ok(Service {
             attrs,
             vis,
@@ -83,19 +97,19 @@ impl Parse for RpcMethod {
                 FnArg::SelfRef(self_ref) => {
                     return Err(syn::Error::new(
                         self_ref.span(),
-                        "RPC args cannot start with self",
+                        "method args cannot start with self",
                     ))
                 }
                 FnArg::SelfValue(self_val) => {
                     return Err(syn::Error::new(
                         self_val.span(),
-                        "RPC args cannot start with self",
+                        "method args cannot start with self",
                     ))
                 }
                 arg => {
                     return Err(syn::Error::new(
                         arg.span(),
-                        "RPC args must be explicitly typed patterns",
+                        "method args must be explicitly typed patterns",
                     ))
                 }
             })