Test bad requests to language server

Author: kddnewton

lib/syntax_tree/language_server.rb

@@ -74,7 +74,7 @@ def run
         in method: %r{\$/.+}
           # ignored
         else
-          raise "Unhandled: #{request}"
+          raise ArgumentError, "Unhandled: #{request}"
         end
       end
     end

test/language_server_test.rb

@@ -174,6 +174,12 @@ def test_reading_file
       end
     end
 
+    def test_bogus_request
+      assert_raises(ArgumentError) do
+        run_server([{ method: "textDocument/bogus" }])
+      end
+    end
+
     private
 
     def write(content)