func TestWithFieldsShouldAllowAssignments(t *testing.T) {
	var buffer bytes.Buffer
	var fields Fields

	logger := New()
	logger.Out = &buffer
	logger.Formatter = new(JSONFormatter)

	localLog := logger.WithFields(Fields{
		"key1": "value1",
	})

	localLog.WithField("key2", "value2").Info("test")
	err := json.Unmarshal(buffer.Bytes(), &fields)
	assert.Nil(t, err)

	assert.Equal(t, "value2", fields["key2"])
	assert.Equal(t, "value1", fields["key1"])

	buffer = bytes.Buffer{}
	fields = Fields{}
	localLog.Info("test")
	err = json.Unmarshal(buffer.Bytes(), &fields)
	assert.Nil(t, err)

	_, ok := fields["key2"]
	assert.Equal(t, false, ok)
	assert.Equal(t, "value1", fields["key1"])
}
func TestDoubleLoggingDoesntPrefixPreviousFields(t *testing.T) {

	var buffer bytes.Buffer
	var fields Fields

	logger := New()
	logger.Out = &buffer
	logger.Formatter = new(JSONFormatter)

	llog := logger.WithField("context", "eating raw fish")

	llog.Info("looks delicious")

	err := json.Unmarshal(buffer.Bytes(), &fields)
	assert.NoError(t, err, "should have decoded first message")
	assert.Equal(t, len(fields), 4, "should only have msg/time/level/context fields")
	assert.Equal(t, fields["msg"], "looks delicious")
	assert.Equal(t, fields["context"], "eating raw fish")

	buffer.Reset()

	llog.Warn("omg it is!")

	err = json.Unmarshal(buffer.Bytes(), &fields)
	assert.NoError(t, err, "should have decoded second message")
	assert.Equal(t, len(fields), 4, "should only have msg/time/level/context fields")
	assert.Equal(t, fields["msg"], "omg it is!")
	assert.Equal(t, fields["context"], "eating raw fish")
	assert.Nil(t, fields["fields.msg"], "should not have prefixed previous `msg` entry")

}
func TestParseLevel(t *testing.T) {
	l, err := ParseLevel("panic")
	assert.Nil(t, err)
	assert.Equal(t, PanicLevel, l)

	l, err = ParseLevel("fatal")
	assert.Nil(t, err)
	assert.Equal(t, FatalLevel, l)

	l, err = ParseLevel("error")
	assert.Nil(t, err)
	assert.Equal(t, ErrorLevel, l)

	l, err = ParseLevel("warn")
	assert.Nil(t, err)
	assert.Equal(t, WarnLevel, l)

	l, err = ParseLevel("warning")
	assert.Nil(t, err)
	assert.Equal(t, WarnLevel, l)

	l, err = ParseLevel("info")
	assert.Nil(t, err)
	assert.Equal(t, InfoLevel, l)

	l, err = ParseLevel("debug")
	assert.Nil(t, err)
	assert.Equal(t, DebugLevel, l)

	l, err = ParseLevel("invalid")
	assert.Equal(t, "not a valid logrus Level: \"invalid\"", err.Error())
}
func LogAndAssertJSON(t *testing.T, log func(*Logger), assertions func(fields Fields)) {
	var buffer bytes.Buffer
	var fields Fields

	logger := New()
	logger.Out = &buffer
	logger.Formatter = new(JSONFormatter)

	log(logger)

	err := json.Unmarshal(buffer.Bytes(), &fields)
	assert.Nil(t, err)

	assertions(fields)
}