Log a warning if attribute names contain a space

Working on it.

Added a logger, please check.

Added test,
@smustgrave please review.

Hey, I am Gautham, at DrupalCon Atlanta, and I am working on testing this

Putting into NW as the pipeline has issues. But maybe someone from DrupalCon will pick up.

@arunsahijpal can you add the steps to reproduce this issue?

Also, I noticed there is a commit related to another issue(#3514939) in this merge request, can you provide some clarification on why it was part of this merge request?

Hi @grallapa2,
As this issue in not like other issues which you can reproduce as I.S says that if you write a wrong attribute name in an element then the drupal just strips it silently without informing the user that he/she has used a wrong attribute so in order to follow a good practice we are going to log a warning before stripping the attribute.
So I've added a logger warning and a test case to check this.

For running this testcase you can do

phpunit core/tests/Drupal/Tests/Core/Template/AttributeTest.php

and if you want to do manual testing on your cli then you may write this

 drush php:eval ' 
  $attributes = new \Drupal\Core\Template\Attribute([
    "valid_attribute" => "value",
    "invalid attribute" => "value",
  ]); 
  dump($attributes->toArray()); 
  \Drupal::logger("debug")->notice("Attributes stored: @attributes", ["@attributes" => json_encode($attributes->toArray())]); 
'

and that issue no. mentioned in that commit is done by mistake, could you please correct it?

Feel free to ask any other query.

Thanks,
Arun

It looks like this belongs to the theme system. If I'm wrong can the issue summary be updated with additional information about why this is relevant to the Link module?