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Javascript Developer - Unable to properly functioning "$" function

  • 2 replies
  • 1 has this problem
  • 3 views
  • Last reply by SuMo Bot

SuMo Bot
SuMo Bot

Hi Mozilla Community,

I am a Javascript Developer and I need a bit of help. This is my first time in a very long time contacting technical support. Please bare with me as I explain my situation. I recommend that someone that is familiar with Javascript and the browser console help test this issue.

I try to create a function in the browser console on a very blank html file. I created a function using the following code "const $ = $ => $". When I called the function with the following code "$('test')" I would get a return of "null". What is expected to return is "test". I have tested other browsers and it would seem to work perfectly fine. These browsers include: Edge, Chrome, Epiphany. I have also tried creating a function like so "const a = a => a". Then I called the function like this "a('test')". The result would be "test".

I had also asked a developer friend of mine to test this out and nothing is wrong on his end. I cannot recall what machine my friend runs but I know it does not run Linux. I wouldn't know well enough but my suspicions lie with the Linux version of Firefox. I have also tried uninstalling and reinstalling Firefox from my computer the results seem to remain the same.

I will attach images for a visual of the situation. I will also leave some specs that might be of concern down below.

Here are my computer specs:

LMDE 4 (debbie) x86_64 Kernel: 4.19.0-14-amd64 Shell: bash 5.0.3 Resolution: 2560x1080 DE: Cinnamon 4.8.6 CPU: AMD Ryzen 7 1700 (16) @ 3.000GHz GPU: NVIDIA GeForce GTX 1070 Memory: 6153MiB / 64414MiB

Firefox Version: 78.9.0esr (64bit)


Please get back to me, Terrance Banh

Hi Mozilla Community, I am a Javascript Developer and I need a bit of help. This is my first time in a very long time contacting technical support. Please bare with me as I explain my situation. I recommend that someone that is familiar with Javascript and the browser console help test this issue. I try to create a function in the browser console on a very blank html file. I created a function using the following code "const $ = $ => $". When I called the function with the following code "$('test')" I would get a return of "null". What is expected to return is "test". I have tested other browsers and it would seem to work perfectly fine. These browsers include: Edge, Chrome, Epiphany. I have also tried creating a function like so "const a = a => a". Then I called the function like this "a('test')". The result would be "test". I had also asked a developer friend of mine to test this out and nothing is wrong on his end. I cannot recall what machine my friend runs but I know it does not run Linux. I wouldn't know well enough but my suspicions lie with the Linux version of Firefox. I have also tried uninstalling and reinstalling Firefox from my computer the results seem to remain the same. I will attach images for a visual of the situation. I will also leave some specs that might be of concern down below. Here are my computer specs: LMDE 4 (debbie) x86_64 Kernel: 4.19.0-14-amd64 Shell: bash 5.0.3 Resolution: 2560x1080 DE: Cinnamon 4.8.6 CPU: AMD Ryzen 7 1700 (16) @ 3.000GHz GPU: NVIDIA GeForce GTX 1070 Memory: 6153MiB / 64414MiB Firefox Version: 78.9.0esr (64bit) Please get back to me, Terrance Banh

All Replies (3)

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer

Hmm, I think I found the issue accidentally. I tried this (on Windows) on a basic page: 

const $ = $ => $;
$('wtf?');
Uncaught DOMException: Document.querySelector: 'wtf?' is not a valid selector

The referenced line for the error is 321 which is part of a function built in to the DevTools -- a helper command:

https://developer.mozilla.org/docs/Tools/Web_Console/Helpers

So... it seems you may need to define $ in your page and not in the DevTools to work around the conflict.

The DevTools team has a forum where you might get other suggestions:

https://discourse.mozilla.org/c/devtools

SuMo Bot
SuMo Bot Question owner

Thanks jscher2000. I'll give it a try after my 2 nightshifts.

SuMo Bot
SuMo Bot Question owner

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