cheesy-arena-lite/websocket/notifier_test.go

// Copyright 2014 Team 254. All Rights Reserved.
// Author: pat@patfairbank.com (Patrick Fairbank)

package websocket

import (
	"github.com/stretchr/testify/assert"
	"io/ioutil"
	"log"
	"testing"
)

func TestNotifier(t *testing.T) {
	notifier := NewNotifier("testMessageType", generateTestMessage)

	// Should do nothing when there are no listeners.
	notifier.Notify()
	notifier.NotifyWithMessage(12345)
	notifier.NotifyWithMessage(struct{}{})

	listener := notifier.listen()
	notifier.Notify()
	message := <-listener
	assert.Equal(t, "testMessageType", message.messageType)
	assert.Equal(t, "test message", message.messageBody)
	notifier.NotifyWithMessage(12345)
	assert.Equal(t, 12345, (<-listener).messageBody)

	// Should allow multiple messages without blocking.
	notifier.NotifyWithMessage("message1")
	notifier.NotifyWithMessage("message2")
	notifier.Notify()
	assert.Equal(t, "message1", (<-listener).messageBody)
	assert.Equal(t, "message2", (<-listener).messageBody)
	assert.Equal(t, "test message", (<-listener).messageBody)

	// Should stop sending messages and not block once the buffer is full.
	log.SetOutput(ioutil.Discard) // Silence noisy log output.
	for i := 0; i < 20; i++ {
		notifier.NotifyWithMessage(i)
	}
	var value messageEnvelope
	var lastValue interface{}
	for lastValue == nil {
		select {
		case value = <-listener:
		default:
			lastValue = value.messageBody
			return
		}
	}
	notifier.NotifyWithMessage("next message")
	assert.True(t, lastValue.(int) < 10)
	assert.Equal(t, "next message", (<-listener).messageBody)
}

func TestNotifyMultipleListeners(t *testing.T) {
	notifier := NewNotifier("testMessageType2", nil)
	listeners := [50]chan messageEnvelope{}
	for i := 0; i < len(listeners); i++ {
		listeners[i] = notifier.listen()
	}

	notifier.Notify()
	notifier.NotifyWithMessage(12345)
	for listener := range notifier.listeners {
		assert.Equal(t, nil, (<-listener).messageBody)
		assert.Equal(t, 12345, (<-listener).messageBody)
	}

	// Should reap closed channels automatically.
	close(listeners[4])
	notifier.NotifyWithMessage("message1")
	assert.Equal(t, 49, len(notifier.listeners))
	for listener := range notifier.listeners {
		assert.Equal(t, "message1", (<-listener).messageBody)
	}
	close(listeners[16])
	close(listeners[21])
	close(listeners[49])
	notifier.NotifyWithMessage("message2")
	assert.Equal(t, 46, len(notifier.listeners))
	for listener := range notifier.listeners {
		assert.Equal(t, "message2", (<-listener).messageBody)
	}
}

func generateTestMessage() interface{} {
	return "test message"
}