From 9297af60db0945f05e26ce872daa24bff42155be Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Mon, 25 Sep 2017 17:16:47 +0000
Subject: [PATCH] [clangd] Fix missing "message" key when responding with
 unsupported method

The language server protocol dictates that a ResponseError should have a
[message string][1] describing the error. This adds a simple message to the
error and a simple test.

[1]: https://github.com/Microsoft/language-server-protocol/blob/master/protocol.md#response-message

Patch by Raoul Wols!

Differential Revision: https://reviews.llvm.org/D38225

llvm-svn: 314119
---
 clang-tools-extra/clangd/JSONRPCDispatcher.cpp        |  2 +-
 clang-tools-extra/test/clangd/unsupported-method.test | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 clang-tools-extra/test/clangd/unsupported-method.test

diff --git a/clang-tools-extra/clangd/JSONRPCDispatcher.cpp b/clang-tools-extra/clangd/JSONRPCDispatcher.cpp
index 2f38e9c..6641aae 100644
--- a/clang-tools-extra/clangd/JSONRPCDispatcher.cpp
+++ b/clang-tools-extra/clangd/JSONRPCDispatcher.cpp
@@ -42,7 +42,7 @@ void Handler::handleMethod(llvm::yaml::MappingNode *Params, StringRef ID) {
   // Return that this method is unsupported.
   writeMessage(
       R"({"jsonrpc":"2.0","id":)" + ID +
-      R"(,"error":{"code":-32601}})");
+      R"(,"error":{"code":-32601,"message":"method not found"}})");
 }
 
 void Handler::handleNotification(llvm::yaml::MappingNode *Params) {
diff --git a/clang-tools-extra/test/clangd/unsupported-method.test b/clang-tools-extra/test/clangd/unsupported-method.test
new file mode 100644
index 0000000..200bae0
--- /dev/null
+++ b/clang-tools-extra/test/clangd/unsupported-method.test
@@ -0,0 +1,19 @@
+# RUN: clangd -run-synchronously < %s | FileCheck %s
+# It is absolutely vital that this file has CRLF line endings.
+#
+Content-Length: 125
+
+{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootPath":"clangd","capabilities":{},"trace":"off"}}
+
+Content-Length: 143
+
+{"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"file:///main.cpp","languageId":"cpp","version":1,"text":""}}}
+
+Content-Length: 92
+
+{"jsonrpc":"2.0","id":1,"method":"textDocument/jumpInTheAirLikeYouJustDontCare","params":{}}
+# CHECK: {"jsonrpc":"2.0","id":1,"error":{"code":-32601,"message":"method not found"}}
+
+Content-Length: 44
+
+{"jsonrpc":"2.0","id":2,"method":"shutdown"}
-- 
2.7.4