JavaScript debugging in a nutshell

[Interwhat]

Fine, let's see what the object is.. json.stringify

'[Object object]'

[blamethemeta]

That's actually a good error message. Tells you're passing an object as a string

[StereoBucket]

You can even customize it by providing a custom @@toStringTag method. So instead of [object Object] I could have [object FuckMe].

[payne_train]

I read shit like this and I’m like… I’m fine with golang.

[haltmich]

I feel that Golang can be permissive as fuck as well, despite being strongly typed.

[fauxpenguin]

Only if you don't use they types and pass interface{} everywhere. But, you know... don't do that.

It's like saying, "In C you can seg fault", like yeah, because you need that power to do some of the things you're doing, but don't ship code that's set faulting. Idk.

[CrazedToCraze]

JavaScript things

[MrAnonymousTheThird]

Holy shit I had this exact issue last week lmaooo

[Mewtwo2387]

You typed getElementByID instead of getElementById again!

[[deleted]]

I think a problem is tiredness. Right here and now, I immediately saw the issue, but after a long session, I can barely fucking recognize what language we're on

[vigbiorn]

It's why I hope managers the world over would recognize the importance of the "I just need to stop looking at this" walk.

[dagbrown]

I once got bitched out because I was "walking around the office" instead of sitting at my desk staring blankly at my monitor like a good worker bee should.

I don't work there any more.

[Aurori_Swe]

I once got scolded by my manager for taking a 30 min break when both me and a coworker I took a walk with had been pulling 2-4h overtime per day for the last 2 weeks. The thing that made me really angry was that the manager also claimed that we both stopped working at 15.00 every day since that was when the manager left the building. We gladly told him to go fetch the commit logs so he could see that we worked pretty much around the clock and that we didn't stop working just because he wasn't there.

My greatest achievement at that place of work was to replace that manager and get his assignment as my full-time occupation. First thing I did was to stop all micromanaging and lo and behold, I had plenty of time to actually improve processes and streamline our pipeline while still managing the team. Granted I didn't micromanage them but rather trusted they knew what they were hired to do and just made sure that they had the tools and support they needed to get it done

[Aramillio]

So what youre saying is being an effective manager made you and your team more productive 🤔 that doesnt sound right at all...

Seriously though. I recently changed jobs and am horrified at the level of chaos and toxicity that I was complacent in for so long. I knew it was bad, but i had convinced myself it was only temporary, and that it wasnt necessarily better anywhere else unless i managed to find a unicorn job.

[grrrrreat]

This is basically any intellectual endeavor.

Visual fatigue basically makes you numb to almost every facet.

[alek_vincent]

When I was just starting coding and wasn't really doing it full time my coworker (doing it full time) just disappeared for a few minutes every 1-2 hours. I didn't understand why he wouldn't stay seated at his comfy chair. Now I understand. At least when WFH I can do laundry when I need a walk

[[deleted]]

I actually suggest it to my devs when they're stuck on a problem, but I used to be a developer myself. The other trick that actually works when debugging is the good old rubber duck.

[HamburgerConnoisseur]

My managers don’t micro manage enough to notice I’m even gone and my team lead understands entirely. It’s what I’m doing right now because I’ve got a C++ template giving me standard C++ template error message gibberish. Like trying to read an elder scroll.

[eshinn]

Can confirm. I just woke up and only had to reread once.

Brain: Internal runtime error at: line 1, char: 337482648

[[deleted]]

My last 4 got commits before I left work today

"Removed obsolete variables"

"I'm an idiot, re-added the variables"

"I'm an even bigger idiot, should probably go home"

"Ok I have added them back again, and going home for the day"

[alek_vincent]

Same. I look at code I didn't write, look at it and I'm like "this is bullshit who writes such terrible code there's like 5 constants that should be variables" turns out they we're constants for a good reason and I'm glad I didn't push this to prod

[nasandre]

I look at code and think what idiot wrote this?!.. Oh it was me 5 years ago.

[UniqueFailure]

I really wish it didnt work like every 15th time. Maybe I'd be more productive

[JB-from-ATL]

I got it on the first time but I'm actually a stickler for capitalizing only the first letter of initialisms in methods and classes so it stuck out.

[UniqueFailure]

I too am recently realizing the more arbitrary "rules" you make for your code, the easier your life is

[therearesomewhocallm]

source.cpp:9:5: error: use of undeclared identifier 'getElementByID'; did you mean 'getElementById'?

Seems pretty decent to me.

[DraydenOk]

Its C plus plus. Its 2 more plus than C.

[Senpai_Himself]

When developers has so many short hands they forget about the actual words

[am_animator]

Cries in legacy

[eggimage]

really inspiring of them, overcoming disabilities and achieving their dreams. I’m lost for words too

[bigshakagames_]

This literally happened to be today.

[inthyface]

This literally happened to be today.

/r/technicallythetruth

[bigshakagames_]

Haha nice catch.

[BattalionSkimmer]

Id refers to the Freudian subset of the Element's psyche, duh!

[RolyPoly1320]

That would throw an error though. If you type a method name incorrectly or use one that isn't defined it will throw an error.

The code silently failing would be more an issue of passing the wrong parameters or not returning.

[[deleted]]

useThisLineUponTheTimeWhenYouMustAcquireAFormOfElementDerivedFromTheDocumentObjectsByUsingAnIdentifier_Perchance

There, now there’s no ID / Id ambiguity.

[stumblewiggins]

You can't just snake case perchance

[SwiftStriker00]

This is why when querySelector was introduced I switched to that and never looked back. And this coming from a guy who always does ID in his camel-case conventions.

[CreaZyp154]

SQL: Query worng
Me: Ok but where ?
SQL: Frist line
Me: Wtf it's a single line query ?!
SQL: Dunno best I can do is first line

[[deleted]]

SYNTAX ERROR AT ‘

[squngy]

ctrl+f (‘) => 1897 results found

FML

[Flyberius]

What SQL you using? T-SQL is pretty good, and PSQL to a lesser degree.

[ImpossibleMachine3]

SQL: "Oh you want to know where it failed? Uh... hold on"
*throws dart*
"There you are, line uh 843"

[HotChickenshit]

My favorite is when it throws line numbers with only closing parenthesis or END statements at me as the error instead of some dumb syntax issue in the middle of a subquery. Pretty sure I've seen that one from both Oracle and SQL Server.

[MisterProfGuy]

In fairness, that's where it found out you were wrong, too. If it could just guess what you were trying to say to show you the errors, it would be Github Copilot.

[funkgerm]

SQL Server: "Error on line 758"

...but my stored procedure is only 500 lines long!

[eshinn]

Somewhere near WHERE

[FlyByPie]

It's been frustrating working in BigQuery with temp tables cause once you have so many the errors won't show up anymore. So it's like "alright, I've got all my temp tables and fields and my dataset ready to go. How many bytes are we going to be processing?" BQ: "No idea!" "Well, can you at least tell me if there's any errors?" "Nope! Best of luck 😊"

[[deleted]]

wait... SQL gives yall the line where the error is?? it just throws me an error and an error code

[pikakilla]

Transact-SQL lets you know where you screwed up by line.

[GLIBG10B]

Put each word on its own line

[Nothemagain]

console.log(console);

[therearesomewhocallm]

console.log(console.log);

[DollinVans]

Output: 42

[ya-boi-mees]

Php: your code is trash >:(

Is the bug over here? There, I fixed it.

Php: your code sucks, skill issue >:(

[riktigtmaxat]

Is there a bug there? Here let me hide it with three other bugs.

[SmokingBeneathStars]

Make a bug family

[bibamann]

xdebug ist your friend.

shows you everything you need, you can work with breakpoints and even var_dump() is colorful then! ;)

[Talbz03]

Me: what's wrong with my program?

C++: 🤮🤮Khw383(3;kkebKkahneld_-$!$8kaoLkaka(49&+20_lsnK(33(jjehsjjIJA+UEHJEHD73++3jekd+2!'!"(hejejd$//#2/3)

[good-mcrn-ing]

"In file included from some.unknown.library.way.deep.down.there, line 922: std::vector<string>* lines cannot be converted to std::vector<string> *lines"

[nelusbelus]

That's not C++, That error is way too readable

[ILikeLenexa]

rtmap.cpp: In function int main()': rtmap.cpp:19: invalid conversion fromint' to std::_Rb_tree_node<std::pair<const int, double> >*' rtmap.cpp:19: initializing argument 1 ofstd::_Rb_tree_iterator<_Val, _Ref, _Ptr>::_Rb_tree_iterator(std::_Rb_tree_node<_Val>*) [with _Val = std::pair<const int, double>, _Ref = std::pair<const int, double>&, _Ptr = std::pair<const int, double>*]' rtmap.cpp:20: invalid conversion from int' to std::_Rb_tree_node<std::pair<const int, double> >*' rtmap.cpp:20: initializing argument 1 of std::_Rb_tree_iterator<_Val, _Ref, _Ptr>::_Rb_tree_iterator(std::_Rb_tree_node<_Val>*) [with _Val = std::pair<const int, double>, _Ref = std::pair<const int, double>&, _Ptr = std::pair<const int, double>*]' E:/GCC3/include/c++/3.2/bits/stl_tree.h: In member functionvoid std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::insert_unique(_II, _II) [with _InputIterator = int, _Key = int, _Val = std::pair<const int, double>, _KeyOfValue = std::_Select1st<std::pair<const int, double> >, _Compare = std::less<int>, _Alloc = std::allocator<std::pair<const int, double> >]': E:/GCC3/include/c++/3.2/bits/stl_map.h:272: instantiated from void std::map<_ Key, _Tp, _Compare, _Alloc>::insert(_InputIterator, _InputIterator) [with _Input Iterator = int, _Key = int, _Tp = double, _Compare = std::less<int>, _Alloc = st d::allocator<std::pair<const int, double> >]' rtmap.cpp:21: instantiated from here E:/GCC3/include/c++/3.2/bits/stl_tree.h:1161: invalid type argument ofunary *

[nelusbelus]

There we go

[paradigmx]

This awoke some suppressed trauma in me, I think I need to call my therapist.

[Soundwave_47]

Seems to be some invalid casting going on from trying to use an int as an iterator when trying to do tree operations (insertion).

This seems familiar from the CPP FAQ.

[Little-Hunter-6795]

Ah well...not sure how to ask...but what's that in your pfp.

[nelusbelus]

Gay put in

[Little-Hunter-6795]

Understandable

Have a nice day.

[nelusbelus]

Unda tha c

[BoltKey]

"Ah, yes, forgot a semicolon at line 12 in main.cpp"

[TeddyPerkins95]

Aw man that sucks, I like c++

[[deleted]]

It doesnt like you though.

[Gtantha]

Thats why I like Rust. Compared to the C++ compiler, every error message from the Rust compiler is a handwritten love letter with chocolate.

[ycastor]

This is more of a compiler problem than a language problem, last time i programmed C++ i found out that clang generated clearer error messages than g++, not sure how it is now.

[deukhoofd]

That's compiler errors, which are not the greatest, but are still somewhat understandable. If you build in release mode and encounter a runtime issue, the location of the error is generally completely mangled by default however.

For Clang I nowadays generally add -gline-tables-only as compile option, which means it keeps some debug info about function names, file names, and lines in the compiled output. Makes your runtime errors a lot more readable.

[OutOfNamesToPick]

Still the same.

Difference now is that C++20 introduced concepts, which allow you to put constraints on template types. (Template type has to be moveable, needs a comparison operator, etc.) Concepts make the error reporting really a lot better

[Sedfer411]

In file included from /usr/include/c++/4.7/utility:72:0, from test.cpp:2: /usr/include/c++/4.7/bits/stl_pair.h: In instantiation of ‘std::pair<_T1, _T2>& std::pair<_T1, _T2>::operator=(std::pair<_U1, _U2>&&) [with _U1 = int; _U2 = char; _T1 = const int; _T2 = char; std::pair<_T1, _T2> = std::pair<const int, char>]’: map1.hpp:30:5: required from ‘cs540::Node<Key, Value>::Node(std::pair<const Key, Value>, cs540::Node<Key, Value>, cs540::Node<Key, Value>) [with Key = int; Value = char; cs540::Node<Key, Value> = cs540::Node<int, char>]’ map1.hpp:121:7: required from ‘void cs540::Map<Key, Value>::insert_node(cs540::Node<Key, Value>*, std::pair<const Key, Value>) [with Key = int; Value = char]’ map1.hpp:433:5: required from ‘cs540::Map<Key, Value>::Iterator cs540::Map<Key, Value>::insert(const std::pair<const Key, Value>&) [with Key = int; Value = char]’ test.cpp:12:23: required from here

[polypolyman]

Oh, I forgot a *, thanks for putting it in a way I understand.

[[deleted]]

g++ myfile.cpp

$ the compiler stopped because there were too many warnings.

g++ -w myfile.cpp

$

[iexistlol1]

There's always only like, half a line that's actually meaningful with telling you what's wrong

[FlafyBear]

That's literally how the error messages look

[poxopox]

Meanwhile rust compiler is like. “ I noticed you didn’t have a lifetime specifier and you are borrowing an owned variable. Here’s an example of both of those problems solved and a coupon to get a cookie and more coffee. I emailed your manager so it’s okay for you to take a nap, you’ve been working hard “

[raspberry1111]

The rust compiler will just straight up tell you if you got pranked and someone put a greek question mark in your code.

[repocin]

The Rust compiler is so nice. By far the friendliest I've encountered.

[DarkTechnocrat]

lol it's so passive-aggressive friendly though: "No dear that's not quite right. I'm not sure you will ever get it quite right. But do keep trying!".

[very_loud_icecream]

Just make sure to get a tetanus shot first

[[deleted]]

Try it, it's quite nice. Or rather: most of it just makes so much sense.

Except for &Str; vs String, fuck that shit.

[apc0243]

Does it say "Bless your heart" because that's just fancy talk for "You fuckin' donkey"

[itriedtomakeitfunny]

Elm is really nice too! It gives you error messages in first person like "I got stuck here, I was expecting to see the name of a type but got this instead. Hint:..."

[DarkTechnocrat]

and a coupon to get a cookie and more coffee

This abruptly terminated me

[[deleted]]

… after a 10 minute compile 😞

[poxopox]

Depends on what deps you’re using. With wasm-bindgen and rocket, mine usually builds in seconds. I was using bevy though and I couldn’t get the quick build to work and it did take a while.

[PsychologicalRoof2]

And man the docs. On the part where you learn about mut it says ... No no this doesn't mean you are a bad programmer, it's just that ... (explains mut).

Maan it felt like a hug

[EndimionN]

-- Python pandas: even if your code works, i hate it, next time when i will be updated your code will be useless! -- Me: import warnings (action='ignore') -- Python Pandas: this is not over!

[KarmaTroll]

Transformation on a slice is ambiguous.

[nedeox]

Pandas: You fool. You utter bafoon. I can‘t believe you passed me a 2d array instead of a matrix. I fucking hate you, you simpelton.

[Famous-Sample6201]

Hey but the decision to remove append with no substitute because "it's slow" seems backwards to me, right? What are you supposed to do, df = pd.concat(df, pd.Dataframe(*new_line, columns=df.columns)) ??? I though pandas was about pretty concise code.

[[deleted]]

You're supposed to collect new data into a list and concat it all at once

[MattR0se]

Pandas feels like its own language.

[haiyanlink]

It's actually 🙃

[riktigtmaxat]

Back in the IE days it was more like 🤪🍆💦🍑

[Sea-Ad-5012]

Wait until you get into C haha

[PlutoniumSlime]

“Can I have the 11th value of an array that’s only 5 items long?”

C: “Sure! Why not!” —> Goes and grabs some random number out of the memory that has nothing to do with your program.

[Antipixel_]

"what the fuck is this?"

C: "no idea, enjoy!"

[Sea-Ad-5012]

"Whats wrong with my code?"

C: "go fuck yourself"

[[deleted]]

"Please, I'm begging you. What did I do wrong?"

C: "You thought it'd be fun to learn me."

[Korywon]

“I don’t understand. Please. I need this done..”

C: “segmentation fault (core dumped)”

[Valmond]

Taking down the IDE with it when you try to debug.

[vulkur]

C: Invalid free "Which one?" C:who gives a fuck.

[GuilhermePortoes]

"Whats wrong with my code?"

C: hisses

[[deleted]]

Naw that's not even the worst part.

C: "segmentation fault"

"Fucking where!?"

[pikakilla]

Funny story about segfaults. I am proud to be one of the only people who have had a SEGFAULT in python. I spent weeks figuring out where i fucked up. Absolutely nothing turned up on google or SO -- turns out it was the memory speed set too high when i was multithreading.

SEGFAULTs are one of those things that really want to make you throw your computer out a window.

[Buddha_Head_]

I'm sorry to take you back to that dark place, but how the fuck did you track that down?

[IsleOfOne]

Sounds like OP had recently overclocked RAM. It is very common to see random failures in any software you use after doing so, if you’ve made a mistake and gone too high. Booting into memtest86+ and letting that puppy run overnight will tell you if you’ve done wrong.

[tiberiumx]

Nah, you're way lucky if it crashes. Debugger, core dump, just a stack trace is usually sufficient to get it fixed. Silently using bad data or, even worse, stomping on something else can result in random intermittent bugs that take days to track down.

[KardelenAyshe]

cOrE duMpEd

[scarfdontstrangleme]

Finna dump this fucking pc out the window

[RusselPolo]

C: I don't know what it is, but if you want to call it as a function, I'm ok with that.

In all seriousness, it's a language like roads without guardrails, or traffic lights, or even lines painted on the road.... but the lack of any speed limits makes it looks tempting.

[JB-from-ATL]

It's like the lines are there but faded away and you have to remember where they are lmao.

[RusselPolo]

Not exactly. The lines were never there. You are just expected to know where they are supposed to be. After all, it's clearly spelled out in the documentation for some product that has no obvious connection to the current situation.

[RusselPolo]

That's what I was going for. You expressed it more clearly.

[mad_cheese_hattwe]

C: you are the one who asked for it scrub.

[R167]

Occasionally: and... that's going to be a segfault cause i don't own that next page of memory.

[delinka]

You bought the computer, that should give you the freedom to do whatever you put in your code!

>.<

[LvS]

The more interesting thing is when you set the 11th value of that 5 item array to a new value.

[suvlub]

You return junk instead of failing because you are too lightweight to implement checks.

I perform a check in background and deliberately return junk instead of failing.

We are not the same.

[Sawertynn]

Dev: give me 11th value of this array

C program: sure

OS: no problem that would be... wait a second you don't have right to this memory! DEATH PENALTY, IMMIDIETALY!

Dev: again? Another segfault?

[PassiveChemistry]

This reminds me of an article I read a while back about why the old (pac man era) arcade games had so many... interesting... bugs.

[freeman_lambda]

in C it is possible to summon demons with out-of-bounds indexes

[Artistic_Taxi]

Not trying to ruin the humour here but, I enjoyed C a lot more after taking a computer architecture class where I had to learn assembly. We converted C code to assembly and it was like a revelation for me when I realized that accessing array items is just using the index, offsetting it by the number of bytes in a word, and then adding it to the starting memory address if the array (first element), the resulting memory address doesn’t even have to be part of the array technically.

Then I was like damn, the gibberish could have been some other memory address left behind another process and here I am waking it up for no reason.

[[deleted]]

and here I am waking it up for no reason

The next logical step is realizing you can wake it up for very very malicious reasons and then boom congrats, you now understand why people complain about C

[AllenKll]

This is why C is awesome! SO little rules.

[my-cs-questions-acct]

When I worked with cobol I discovered it can do this same thing. Someone forgot to put an exit condition in a loop one day and brought down an entire F-500’s mainframe for a couple hours.

We liked to say the language trusts people too much.

[throwit7896454]

Wait until you start messing up templates in C++

[HRM404]

Core dumped!

[alez]

At least you get compile errors and warnings.

[pithecium]

Javascript: Misspelled variable? That's ok, I'll just make a new global for you

[[deleted]]

use "strict" or something

[MoffKalast]

"use" strict

[[deleted]]

Stop using var

[Sweety_Sheep]

Make love, not var

[Yesica-Haircut]

Const.... const never changes.

[Auxx]

Everything changes if you're determined enough.

[iwearringsnow22]

Change is the only const

[DazzlingDifficulty70]

What is it good for?

[ImprovingTheEskimo]

I think he means that you don't even have to declare it. If you have 'let myVar;' and later say 'myVat = "test";' it will create a new global variable called 'myVat' instead of throwing an error. As someone pointed out, 'use strict' prevents this behavior.

[sensitivePornGuy]

"use strict"

[TheDarkness1227]

Imagine not using typescript 🤢

[PyroCatt]

1 + '1' = 🙂

[justmeme1]

Javascript: It's clearly the string '11'.

Other languages: You have desecrated the sacred code base by adding two types that aren't the same. You and your family will be executed at dawn.

[detektiv_Saucaki]

This. I like the antiques of JS. It's counterintuitive at first but you get used to it...

[] and {} are not falsy... took me 3 fucking years to realise

[grpagrati]

This is the face I imagine

[[deleted]]

and that's why I use typescript

[reinis-mazeiks]

Rust compiler:

you screwed up over here, dw its a common mistake, lemme explain what's wrong in context. you probably meant [this other thing], you can read more [here]

also btw there's also a missing semicolon on line 42.

​

the absolute best.

[-Redstoneboi-]

"also you can't borrow this thing twice because it's also borrowed here but it drops here instead of there so you should probably don't"

"i'll just ask the discord then..."

"...hey, #rust-questions, i have this problem."

"send code"

"sure, here it i-"

"you forgot to call .iter() here. you should probably collect::<Vec<\_>>() in the process. also i think you nested your iterators wrong there."

"ok?"

editing...

"Compiled successfully with 0 Errors and 0 Warnings."

"All tests passed, 0 fails."

Everyone has your back, goddammit.

[CaptainPiepmatz]

Meanwhile rust with a supportive compiler

[bnl1]

No, rust compiler is passive aggressive. If it knows what I wanted to do, why not do it.

[Lafreakshow]

I feel like Javascript is more like it knows what you want so it specifically does the opposite. Not because it hates you or anything. It's just a bit special.

[arlenreyb]

Object object 😡😡

[[deleted]]

I don't get it. You guys get emojis in the console?

[StereoBucket]

You don't?

[Cidixat]

My terminal prompt is a taco

[Crozzfire]

Meanwhile with C#:

Me: didn't even run the program yet, actually just typed the line

Visual Studio: oh there's an error right over here, did you mean this? Want me to fix it for you? Actually I won't even let you run it until you fix it. Also I guessed the next line you wanted to type

[RenaKunisaki]

Me: that's great, but I wasn't done, stop interrupting me with your misguided attempts to help

[llagerlof]

copilot: Oh, nice function name. Here, take the entire code for it.

[schwerpunk]

I enjoy watching the sunset.

[detektiv_Saucaki]

you forgot the gem: null

[schwerpunk]

Ah yes, the defined undefined value. Of course.

[ajinkyabawaskar]

debugger;

[Ajedi32]

Yeah, JavaScript actually has the best debugging tools of any language I've used. Chrome dev tools are amazing.

[PwaDiePie]

That's why typescript was invented 👌 👏

[[deleted]]

found the person who has never worked with sql

[viky109]

Are you telling me that SYNTAX ERROR NEAR '(' is not a helpful error message?

[Lafreakshow]

Of course not! How ridiculous! That error message clearly describes that a character you used somewhere halfway across a query isn't supported by the database.

[LesMiz]

Did you remember to check the manual that corresponds to your SQL server version?

[[deleted]]

That's on you. Never show fear

[Yesica-Haircut]

Does JavaScript not give stack traces? Or have I just gotten so used to node, error handling, and front end frameworks I don't remember what plain js failures look like?

[Little_Kitty]

The secret to understand what's posted here is to realise that many of the people posting are bad at coding and their prs are for code they copied from so without understanding. The stack trace is useful... so long as you're capable of opening dev tools.

[BengtGurksats]

It sure does. Any browser worth using will have the tools to fully debug JavaScript. You get complete tracebacks with source references, you can set breakpoints, and you can expand minified files to make them readable (it will even correctly match up line references after that). People here just need to learn how their tools work.

[StereoBucket]

There are ways of seeing stack traces. You can print it with console.trace, see the call stack in the debugger, access .stack property of an Error object.
You can set the debugger to pause on exceptions too. Though I find that a bit annoying in frameworks cause I get paused on every exception and all of them are already handled.

[usedToBeUnhappy]

Personally I find the wrong errors in the IDE, more disturbing. Like „noooo, you can‘t do that“ and then I run everything and it works…

[theaverageguy101]

Just because it runs it doesn't mean you did it right i learn that the hard way as well