Handle JSON parse error

Author: andyw8

lib/ruby_lsp/ruby_lsp_rails/runner_client.rb

@@ -61,9 +61,12 @@ def send_message(request, params = nil)
       def read_response
         headers = @stdout.gets("\r\n\r\n")
         raw_response = @stdout.read(T.must(headers)[/Content-Length: (\d+)/i, 1].to_i)
-        response = JSON.parse(T.must(raw_response), symbolize_names: true)
 
-        # TODO: handle exception if JSON parse fails?
+        response = begin
+          JSON.parse(T.must(raw_response), symbolize_names: true)
+        rescue JSON::ParserError => e
+          { error: e.message }
+        end
 
         if response[:error]
           warn("Ruby LSP Rails error: " + response[:error])