Make sure JSON parser returns Hash

Record must be Hash.

Signed-off-by: Daijiro Fukuda <fukuda@clear-code.com>

lib/fluent/plugin/parser_json.rb

@@ -71,6 +71,9 @@ def configure_json_parser(name)
 
  def parse(text)
  record = @load_proc.call(text)
+ # Sometimes the parser returns String, not Hash.
+ # Ex. Oj.load('"hoge"') => "hoge"
+ raise @error_class unless record.is_a?(Hash)
  time = parse_time(record)
  if @execute_convert_values
  time, record = convert_values(time, record)

test/plugin/test_parser_json.rb

@@ -135,4 +135,30 @@ def test_yajl_parse_io_with_buffer_smaller_than_input
  end
  end
  end
+
+ sub_test_case "various record pattern" do
+ data("Only string", { record: '"message"', exepected: nil }, keep: true)
+ data("Only string without quaot", { record: "message", exepected: nil }, keep: true)
+ data("Only number", { record: "0", exepected: nil }, keep: true)
+ def test_oj(data)
+ @parser.configure('json_parser' => "oj")
+ @parser.instance.parse(data[:record]) { |time, record|
+ assert_equal(data[:expected], record)
+ }
+ end
+
+ def test_yajl(data)
+ @parser.configure('json_parser' => "yajl")
+ @parser.instance.parse(data[:record]) { |time, record|
+ assert_equal(data[:expected], record)
+ }
+ end
+
+ def test_json(json)
+ @parser.configure('json_parser' => "json")
+ @parser.instance.parse(data[:record]) { |time, record|
+ assert_equal(data[:expected], record)
+ }
+ end
+ end
 end