Tags: bug

31

sparkline

Monday, April 30th, 2018

Apart From Code

A good developer…

  • debugs
  • follows the KISS principle (and respects YAGNI)
  • knows how to research
  • works well with others
  • finds good developer tools
  • tests code

Sunday, March 4th, 2018

The People Part of Design Systems – Related Works – Medium

I like the idea of “design bugs”:

Every two weeks or so, a group of designers would get together for a couple of hours to fix what we called “design bugs.” These were things that didn’t hinder functionality and wouldn’t have been filed as an engineering bug, but were places where we were using an old component, an existing one incorrectly, or a one-off alteration.

Monday, July 31st, 2017

rachelandrew/gridbugs: A curated list of Grid interop issues

Rachel is maintaining this (short) list of browser bugs with CSS Grid, inspired by the excellent Flexbugs.

Grid shipped into browsers](https://gridbyexample.com/browsers) in a highly interoperable state, however there are a few issues - let’s document any we find here.

Friday, July 21st, 2017

Patterns Day 2017: Rachel Andrew on Vimeo

Rachel’s fantastic talk from Patterns Day. There’s a lot of love for Fractal specifically, but there are also some great points about keeping a pattern library in sync with a live site, and treating individual components as reduced test-cases.

Patterns Day 2017: Rachel Andrew

Sunday, April 10th, 2016

A debugging thought process

Remy walks us through his performance debugging routine …and now Una must write him a song.

Wednesday, February 10th, 2016

Handling redirects with a Service Worker

When I wrote about implementing my first Service Worker, I finished with this plea:

And remember, please share your code and your gotchas: it’s early days for Service Workers so every implementation counts.

Well, I ran into a gotcha that was really frustrating but thanks to the generosity of others, I was able to sort it out.

It was all because of an issue in Chrome. Here’s the problem…

Let’s say you’ve got a Service Worker running that takes care of any requests to your site. Now on that site, you’ve got a URL that receives POST data, does something with it, and then redirects to another URL. That’s a fairly common situation—it’s how I handle webmentions here on adactio.com, and it’s how I handle most add/edit/delete actions over on The Session to help prevent duplicate form submissions.

Anyway, it turns out that Chrome’s Service Worker implementation would get confused by that. Instead of redirecting, it showed the offline page instead. The fetch wasn’t resolving.

I described the situation to Jake, but rather than just try and explain it in 140 characters, I built a test case.

There’s a Chromium issue filed on this, and it will get fixed, but it in the meantime, it was really bugging me recently when I was rolling out a new feature on The Session. Matthew pointed out that the Chromium bug report also contained a workaround that he’s been using on traintimes.org.uk. Adrian also posted his expanded workaround in there too. That turned out to be exactly what I needed.

I think the problem is that the redirect means that a body is included in the GET request, which is what’s throwing the Service Worker. So I need to create a duplicate request without the body:

request = new Request(url, {
    method: 'GET',
    headers: request.headers,
    mode: request.mode == 'navigate' ? 'cors' : request.mode,
    credentials: request.credentials,
    redirect: request.redirect
});

So here’s what I had in my Service Worker before:

// For HTML requests, try the network first, fall back to the cache, finally the offline page
if (request.headers.get('Accept').indexOf('text/html') !== -1) {
    event.respondWith(
        fetch(request)
            .then( response => {
                // NETWORK
                // Stash a copy of this page in the pages cache
                let copy = response.clone();
                stashInCache(pagesCacheName, request, copy);
                return response;
            })
            .catch( () => {
                // CACHE or FALLBACK
                return caches.match(request)
                    .then( response => response || caches.match('/offline') );
                })
        );
    return;
}

And here’s what I have now:

// For HTML requests, try the network first, fall back to the cache, finally the offline page
if (request.headers.get('Accept').indexOf('text/html') !== -1) {
    request = new Request(url, {
        method: 'GET',
        headers: request.headers,
        mode: request.mode == 'navigate' ? 'cors' : request.mode,
        credentials: request.credentials,
        redirect: request.redirect
    });
    event.respondWith(
        fetch(request)
            .then( response => {
                // NETWORK
                // Stash a copy of this page in the pages cache
                let copy = response.clone();
                stashInCache(pagesCacheName, request, copy);
                return response;
            })
            .catch( () => {
                // CACHE or FALLBACK
                return caches.match(request)
                    .then( response => response || caches.match('/offline') );
                })
        );
    return;
}

Now the test case is working just fine in Chrome.

On the off-chance that someone out there is struggling with the same issue, I hope that this is useful.

Share what you learn.

Friday, January 22nd, 2016

The Art of Debugging

I was just helping out with some debugging at work and it reminded me of this great talk/post by Remy:

  1. Replicate: see the bug
  2. Isolate: understand the bug
  3. Eliminate: fix the bug

Monday, December 7th, 2015

philipwalton/flexbugs

A list of known bugs (and workarounds) in flexbox implementations. This is going to be handy to refer back to.

Monday, November 16th, 2015

Online regex tester and debugger: JavaScript, Python, PHP, and PCRE

Regular expressions are my kryptonite. I’m rubbish at them and I can never keep the vocabulary in me head.

Mark recommended this tool so I’m going to give it a go the next time I have to resort to regex.

Friday, January 2nd, 2015

Taking Chrome DevTools outside of the browser. — Kenneth Auchenberg

Kenneth has isolated Chrome’s dev tools into its own app. This is a big step towards this goal:

Why are DevTools still bundled with the browsers? What if clicking “inspect element” simply started an external DevTools app?

With DevTools separated from one specific browser, a natural next step would be making the DevTools app work with other browsers.

Wednesday, April 23rd, 2014

webcompat.com

I like this idea. It would be nice to see it catch on…

  1. Report a bug for any website or browser.
  2. Our team of volunteers diagnoses the bug.
  3. We send a fix to the site owner or browser.

Friday, October 5th, 2012

iOS Six Fix

Last Christmas I gave you my bug report. Well, more of a whinge really. Scott put together a much better bug report and test page:

When the meta viewport tag is set to content=”width=device-width,initial-scale=1”, or any value that allows user-scaling, changing the device to landscape orientation causes the page to scale larger than 1.0. As a result, a portion of the page is cropped off the right, and the user must double-tap (sometimes more than once) to get the page to zoom properly into view.

Yes, it’s the old orientation and scale bug in Mobile Safari.

I’m pleased to report that as of iOS version 6, this bug seems to have finally been squashed. Hallelujah!

Given the relatively rapid upgrade path for iPhone, iPod Touch and iPad users, it won’t be long until we can remove our clever solutions for working around this problem.

Stand down, hackers, stand down. This bug has been taken care of.

Jeremy caught the mantis

Friday, March 23rd, 2012

scottjehl/Device-Bugs

Scott has created a one-stop-shop for documenting browser bugs in mobile devices. Feel free to add to it.

Wednesday, March 7th, 2012

Adobe Shadow | preview mobile web - Adobe Labs

Adobe have launched their version of Weinre, the tool that allows you to refresh and debug iOS and Android browser views from your desktop computer.

Friday, January 6th, 2012

A Fix for the iOS Orientationchange Zoom Bug | Filament Group, Inc., Boston, MA

That Scott is one smart cookie. He has come up with a workaround (using the accelerometer) for that annoying Mobile Safari orientation/zoom bug that I blogged about recently.

I still want Apple to fix this bug as soon as possible—the fact that such smart people are spending so much effort on ingenious hacks shows just how much of a pain-point this is.

Saturday, December 24th, 2011

iWish

Dear Apple Claus,

I’ve been a very good boy this year so I hope you don’t me asking for a little present. What I’d really like for Christmas is for you to fix that strange orientation scaling bug in Mobile Safari.

Just in case you’ve forgotten about it, my friend Scott—who has been a very, very good boy this year (what with that whole Boston Globe thing)—put together a test page quite a while back to demonstrate the problem.

Basically, if I set meta name="viewport" content="width=device-width, initial-scale=1.0" then it means a pixel should be equal to a pixel: in portrait view, the width should be 320 pixels; in landscape view the width should be 480 pixels. But in Mobile Safari, if I move from portrait to landscape, the width jumps to a value larger than 480 pixels, which means the hapless user must double tap to bring the scale down to 1:1.

Now, admittedly, I could just set meta name="viewport" content="width=device-width" and leave it at that (or I could additionally declare minimum-scale=1.0). But then when the user changes from portrait to landscape, although it doesn’t have the same over-zooming behaviour, it does scale up. That means I’m not getting the full 480 pixels (it’s effectively still a 320 pixel wide display, even in landscape).

I could make the bug disappear by adding maximum-scale=1.0 or user-scaleable=no but that’s the cure that kills the patient. I also did some hacking with Shi Chuan but what we come up with still feels fairly clunky.

So that’s why I’m writing to you, Father Applemas. Won’t you fix this bug for me?

My friend PPK thinks you won’t fix this bug because it would trigger a reflow (and repaint) of the page …but I know that can’t be the reason because the bug doesn’t occur when going from landscape to portrait!

Also—and this is the really strange part—If I’m looking at a web page on my iPhone/Pod in a custom browser (like the Twitter app), rather than using Mobile Safari, then the bug doesn’t occur.

I don’t get, Apple Claus. Why have one behaviour for webviews in other people’s apps and a different behaviour for your own app?

Anyway, if you could see your way to granting this boy’s wish, it would make for a webby Christmas.

Hugs and kisses,

Jeremy

P.S. By this time next year, it would be lovely to have access to the camera (and other device APIs) from the browser …but I’m getting ahead of myself.

Update: the bug has been fixed in iOS 6.

Sunday, December 4th, 2011

iOS scale bug stays (mostly) « « David Goss David Goss

Well, this is very intriguing: it turns out that the infamous orientation/scale bug in Mobile Safari isn’t present in in-app browsers (UIWebView). Most odd.

Friday, May 14th, 2010

New Programming Jargon — Global Nerdy

Some of the best neologisms in programming, many of them to do with bug-fixing.

Tuesday, January 12th, 2010

Wednesday, July 8th, 2009

Bug 25267 – Autobuffer on <audio /> cannot be disabled

This single issue is what's stopping me using the HTML 5 audio element on Huffduffer.