Yavor Kirov YavorK

Stuff I wish I'd known sooner about service workers

I recently had several days of extremely frustrating experiences with service workers. Here are a few things I've since learned which would have made my life much easier but which isn't particularly obvious from most of the blog posts and videos I've seen.

I'll add to this list over time – suggested additions welcome in the comments or via twitter.com/rich_harris.

Use Canary for development instead of Chrome stable

Chrome 51 has some pretty wild behaviour related to console.log in service workers. Canary doesn't, and it has a load of really good service worker related stuff in devtools.

	<!DOCTYPE html>
	<html>

	<head>
	<title>Hello Page</title>
	<script src="https://unpkg.com/htmx.org@1.9.2"></script>
	</head>

	<body>
	<h1>Hello</h1>

	<html>
	<body>
	<div id="result"></div>
	<script>
	if (typeof(EventSource) !== 'undefined') {
	console.info('Starting connection...');
	var source = new EventSource('/stream.php');
	source.addEventListener('open', function(e) {
	console.info('Connection was opened.');
	}, false);

	// PHP < 5.3.6
	foreach (debug_backtrace() as $trace)
	{
	echo sprintf("\n%s:%s %s::%s", $trace['file'], $trace['line'], $trace['class'], $trace['function']);
	}
	die;

	// PHP >= 5.3.6
	debug_print_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
	die;