Those silly mistakes we all make

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I've been developing for years. Years! Yet every now and then something that turns out to be simple floors me for just a little bit longer than is comfortable.

Working with code really can keep you humble. What always catches you out or got you stuck recently that really shouldn't have?

Share your silly mistakes and maybe we'll all feel a bit better about it.

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Why aren't my changes having any affect?

Restart the servers β€” Nothing.
Clear development cache β€” Nothing.
Scour docs for hard restart options β€” Nothing
Print a bunch of <h1>Test test test</h1> all over the page β€” Nothing.

Oooooohhhhhh I'm looking at the production app.


I've done this so many times, for each combination possible out of dev, staging and production.

So. Many. Times.


Better than the version of this I did a long time ago (back when all this was the wild west). I was updating live, not the test site I was looking at.
There's all sorts of things stopping me doing that now.


I've done the same several times, except the screen I was looking wasn't even an app - it was an Invision prototype.


Colour coding works for me with UIs.. not quite so easy with APIs!


Yes! This! More often than I'd care to admit. Have considered popping in a big red "DEV" block somewhere on the site to make it super obvious.


This is actually an excellent idea and I'm pretty sure there are dev teams out there that do this. The more obvious the better!

I am one of them :)
I use big red button with text β€œtest” in navigation bar.


I did something like that once... except I was looking at test and had OVERWRITTEN the production app. Good thing we have backups. Heh heh.


Many times i update code in build folder's source file and the changes are not reflected. After several try i recognised that i'm a idiot.


When I was doing Ruby I always misspelled initialize!


How did you spell it? As a Brit I am, of course, offended by the "z" and think it should be initialise anyway.


Lol, it wasn't a consistent misspelling, it's just a long word I kept fat-fingering.

What was most frustrating was that I wouldn't get a consistent "no method 'intialize'" error, it's just that I wasn't getting expected behavior and it would take me forever to realize it's because my initialize method wasn't being called!

Ah, the nightmare of a misspelled constructor. It's there, it's just pretending it's a regular method. Cheeky. And hard to track down. 😑

What are you writing things in most at the moment? And is it saving you from constructor woes?

These days I work mostly in Go, but even in languages with constructors I struggled with them enough that I now recognize a misspelled one sooner.

Programming has helped me discover that I truly never learned "I before E except after C". I'm always misspelling the BadgeAchievement model in the codebase.

As a Canadian I occasionally have hangups with keywords like color. Phil, you probably feel this too.

That's why we have postcss-spiffing.

body {
  background-colour: grey !please;

Top Tip!

Rename the BadgeAchievement model to BadgeAcheivement and never have this problem again!

I'm sure there are things like this in the code already 😭

Unrelated, but my last job had a referrals-based business model, so you can imagine the referrals table in their database was the most important table with indexes on almost every other table in the database.

It was spelled referalls, and every table apparently has its own convention of whether to name their column referall_id or referral_id πŸ€¦β€β™‚οΈ

I once fixed a misspelling in a codebase without realizing that the name was coming from an external API's response so my correction broke everything. Misspellings that you can't fix are very frustrating.

@yechielk At least that's just in one app and not the Referer header supported in every web browser and server in the world.

Come to think of it, I bet the Referer header has caused multiple spelling confusions leading to things like this.

@halldjack Oh no! You must have thought you were fixing a bug instead of causing it. That's the worst!

Yes! Someone pointed out the referer header to me once, and I instantly felt better for the poor developer who created that referalls table...


Same! Also I type reutrn way more often then I type return. Every. Time.


for me it's retrun lol
i also embarrassingly wrote pubic instead of public during a tech talk

I’ve done similar typos with β€˜countryCode’ πŸ˜‚πŸ™ˆ


Love this, my worst nightmare was something like this πŸ‘‡

<script type="text/javscript" src="main.js"></script>

I spend hours trying to see why it's not working. Obviously it was a long time ago and I had no idea you could look into network calls inside browser πŸ€·β€β™‚οΈ


That's one issue with browsers not complaining if they can't do something.

"Sure," it thought, "this is a classing javscript file, shame I don't know how to parse and run them, on with the next element!"

So useful at times, so painful when it's a typo!


So you wrote that function, but it doesn't work and you have no idea why.

But did you MAKE a CALL to that function SOMEWHERE in your code or it just sits there alone and lonely? :))

Seriously, when I focus so much on functionality, sometimes I forget to call that newly created function. That's why I started calling the function first, and then start writing the function itself.


Or even write a test for the function first πŸ˜‰


omg this happened to me the other day... but I usually call the function first so it didn't dawn on me to check for the function till after a couple of hours just to make sure and BOOM, no function... I added the function, confirmed it worked and closed my editor. Didn't code for the rest of the day.


I spent literal HOURS about a decade back trying to debug a program only to realise I had written a 'j' instead of an 'i' on a for loop but I couldn't tell as the font for both was so similar.

I've not used 'j' as a variable since then ;-)


I always used to go in the opposite direction for this reason. Need something after i? Go for h.


I just avoid 'i' entirely now. Go for something like x, y, z if required ;-)

No more single letter variable names! What is this, degree level mathematics?

Wait, are you all Haskell programmers?

If it's used as a counter in a for loop I don't see an issue with it.

Personally I learned to program with C (and LISP) and sometimes my Javascript still sinks back towards into the C.


On prod env:

  • drop table <important_table_here>;
  • update <table> set <sequential_field> = <constant_val>

:( now i check ten times before run a command :(


Oh yeah, this happened to me once. Ran an update without a where clause, and in the moments after that, I had planned my exile to a remote village in Scotland.
Fortunately, I had run select before the update, and it was a small table so al the data was on the terminal.

SET AUTOCOMMIT=0; after that.


Sounds like a good time to test your DB backups too!


extends when I mean implements as well as using / instead of \ or not including enough extra slashes to escape them. :(


using/import extends/implements/: ... too many languages in the same head :)


The thing is typescript has both extends and implements so it makes it even worse


That's a favourite of mine too. A great way to write a correct action in Rails and then watch it fail to work in tests and routes.

I could almost see the Rails team agreeing to alias common misspellings like this to avoid the heartache!


I left out a backlash in an endpoint. I had to ask for help from another Senior Dev. He then pointed out that to me. I looked very stupid but I guess it's all part of the work.


I looked very stupid but I guess it's all part of the work.

I find that the longer I work in the dev field the more my questions for other devs move towards the edges. Either they are complex architecture-y questions or I'm doing something mind-numbingly dumb and can't see it myself.


I think my point behind all of this is that we all make these mistakes. Likely every day. Most of the time we catch it ourselves. Some of the time the fix is pointed out by someone looking at it with fresh eyes. Once in a while we ship it to production.

If we can all agree that we're not looking stupid or dumb when this stuff happens, then we'll be more likely to ask for help, more likely to catch issues, less likely to spend minutes/hours/days on something and more likely to ship a quality product.


Sometimes you just need a second pair of eyes. If you spend so long looking at your code, you won't be able to see the forest for the trees :) I never judge a developer if the solution is simple, because I know I have been and will be in the same situation soon!


I’d never worked with Visual Studio before and for a long time I’d forget to commit changes to the project file, so that everything worked locally but when my colleague pushed changes, there was no reference to new files and the site would compile without them.


A classic "works on my machine" πŸ˜„

Forget committing changes. Backup the rest of your work and send your laptop up to prod!


The bit that hung me up was that the files themselves WERE committed and present, and the other developer could see them, but since they weren't referenced in the .csproj file, they didn't make it production. I don't know how many times I did that in the early going.

Oh that's so weird. I've not worked with C# or Visual Studio and this would definitely catch me out.


Whenever I did jQuery code, I wouldn't understand why my code didn't execute. turns out I would forget the period in the selector... $('dropdown').show()


I have the opposite! Now I have to kick myself every time I write document.getElementByID('#some-id'). πŸ˜…


I'm forever missing out the dot for a class so made a snippet that does it for me


I sometimes mix up the href and src in the link tag in html.
<link rel="stylesheet" type="text/css" src="theme.css">
instead of
<link rel="stylesheet" type="text/css" href="theme.css">
and it has taken me and colleagues several refreshes to figure out in the past.

"The css file is there. Why isn't it loading? Did you clear the cache? Did you restart the laptop? Did you check the URL?..."


I feel that pain. HTML is both forgiving ("the page still loaded") and brutal ("but it didn't work and I don't know why") at the same time.


I couldn't understand why a new feature wasn't working after I added some fields to a table. It was driving me nuts!

Turns out I forgot I was connected to the tester's DB instead of dev.


Meanwhile the tester has no idea why their DB is sprouting fields.

I love this one, it's not one I've done (no-one else lets me connect to their DB 😁) but I can still feel the intense frustration knowing you added the fields but finding them nowhere in your dev app.

There can never be too many banners telling you what environment you are currently working with.


Most of the time what I do is change something on the local api and query the hosted api for the changes via postman. Will go like this for about 5 minutes restarting and console logging the code until my sight gets the glimpse of the url in postman . Silly me


Ouch. And you can't even place a visual banner to say it's dev/staging when it's an API request.


Late reply - but a thought occurred to me - what about a response header 'X-Environment: test/dev/prod', that might help when staring at Postman for the umpteenth time?

Might help! Though I know I would likely be looking at the body of the response rather than the headers. Sometimes there’s just no guard against ourselves πŸ˜„


For the life of me I couldn’t figure out why my Angular Material component wasn’t emitting events the other day. After about an hour of pulling my hair out, I realized I had written (seletionChange) instead of (selectionChange) in the template


Are you saying you couldn't c the issue? πŸ˜‚


I think I prefer destory.. we're done now folks, time for bed.


I'll always add a new route to my Rails app and forget to restart the local server. After 10 minutes of wondering why the hell my code doesn't work anymore, I'll 🀦.


The worst thing is when you know all the code is right and you just don't know why it's not running. And then...

Have you tried turning it off and on again


Probably my most annoying habit, that gets me far too often:

% vi whatever.c
% gcc whatever.c
% ./whatever
bash: ./whatever: No such file or directory
% {grumbling} mv a.out whatever
% vi Makefile

Too much haste, should always write the Makefile first!


Hehe, I've trained myself to start every project, no matter what, with some sort of project generator script to make all the files I need. I've definitely spent my time grumbling over this sort of thing before though πŸ˜…


Once spent 2 days wondering why my login component wasn't rendering.....
Was looking on the wrong page πŸ˜‚πŸ˜‚πŸ˜‚πŸ˜‚

Luckily this was in my practice days and not anything serious.

Still not sure why I decided to pursue it as a career after that


I also have a tendency to type isntall instead of install and then imagine β€œisn’t all” as a command to delete everything (β€œmake isn’t all that is!”) because my brain is weird.


That misspelling is so common that npm aliases isntall to install so you never have to notice you got it wrong! πŸ˜…

In fact, I just checked and they have a whole bunch of "affordances" for us fat fingered typists! verison might be my favourite.


Could not get a Lambda .NET core project to run locally with AWS toolkit earlier, spent about 1/2 hour digging around and searching for some missing dependency - ended up asking another dev - turned out I just set the wrong start up project in VS πŸ€¦β€β™‚οΈπŸ€¦β€β™‚οΈπŸ€¦β€β™‚οΈ


That moment when you are setting up a web server and you don't understand why it's not loading your index.html on both HTTP/HTTPS. Oh wait, firewall (AWS EC2 -.-")

A quick search on Google doesn't show anything, but I still wouldn't be surprised if there's something out there 😁


pm2 reset app instead off pm2 restart app, and was wondering what impossible bug have i introduced into my code, because i couldn't fix it πŸ€¦β€β™‚οΈ

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Phil Nash profile image
Developer evangelist for Twilio and Authy. I write JavaScript and Ruby. Probably listening to ska punk right now. console.log('🍻');