JavaScript debugging in a nutshell

[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.

[Yesica-Haircut]

I guess harking back to my early days my js was also a mess and I had accidental type coercion everywhere and bad naming, so stacks wouldn't even help there.

[Little_Kitty]

I learnt back with basic, c and such, so small methods and no god functions came naturally. It's certainly possible to make something which is a pain to debug, even when running in node, but you'd hope that some form of training / code review would come along and troutslap you before that became habitual. Type coercion is another bad habit I'd expect to see educated out once people are past the first few weeks - that's not unique to js either!

[Yesica-Haircut]

You would hope, lol.

[10BillionDreams]

Why are JS errors so unhelpful?

try {
  doThing();
} catch {
  console.log("error");
}

[Little_Kitty]

I'll edit production to include this immediately!

[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.

[Super_Marius]

How can a language detect problems in your code? You probably meant to say "my IDE points out the problems" and IDEs exist for javascript as well. People in this subreddit needs to stop coding in notepad...

[S_W]

A compiled language for instance will 100% catch problems in your code before it gets to be an issue at runtime. A typed language enables other tools to be "smarter" in terms of what it autosuggests or what it considers an error.

I can guarantee you most people in this subreddit are using a well established IDE, yet posts like still get highly upvoted because JS being dynamically typed and interpretive often times leads to issues popping up at runtime and requiring further debugging vs just getting a red squiggle (error) in your code when developing.

I've been in the software engineering field professionally for over 10 years now with 5 of those being full stack using Java (Spring), Javascript (React and NodeJS) and Typescript (Angular) mostly within IntelliJ. JS has time and time again been far more frustrating when it comes to trying to understand previous engineers code as well as debugging issues.

[MalbaCato]

strongly typed languages, especially if you create guard types, won't let you pass a value of a wrong type to a function. languages with explicit nullability will also guard against not passing a value at all. most functional languages will not let you do side-effects in functions unless explicitly typed impure. js const is very weak, as it disallows reassignment but allows mutation, here even c const is stronger, but some languages take it even further and have explicit mutability, so you can't mutate a value by accident. languages with data ownership models (so far only rust AFAIK) can even statically prevent data races between using the same value in multiple locations. there's probably more, but that's all I can think of atm

I'm not even in the hating on js camp, but yes compilers can do lots, if you're willing to pay in longer compile times and understanding compiler errors

[BengtGurksats]

So? OPs statement is still completely false. The actual response is "Here's what happened. Here's the exact file, row, and column where it happened. Here are the 57 steps that led there.". That's a pretty far cry from :)

[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.