Ensure theme template headers in style.css has proper line breaks/spacing in it

[rebeccahum]

Basic Info	-
Rule type:	Error
Sniff Category:	CoreFunctionality (I think?)

Having bad spacing/incorrect line breaks in the theme style.css "Template:" header will prevent a child theme from working properly.

Rule:

Couldn't find anything in the handbook but I found this: https://codex.wordpress.org/Theme_Development#Theme_Stylesheet

Theme check file covering this rule:

https://github.com/WordPress/theme-check/blob/da79a6f17b126b52998474cd234e4210de5a2d6f/checks/style_needed.php
https://github.com/WordPress/theme-check/blob/da79a6f17b126b52998474cd234e4210de5a2d6f/checks/style_suggested.php
Closest I could find ^^

[For new sniffs only] Code Samples:

// Code sample(s) which should pass.
/*
Template: test-dir/test-template
Version: 1.0
*/

// Code sample(s) which should be flagged by the sniff.
/*
Template: test-dir/test-template Version: 1.0
*/

When get_file_data() will try to parse the above, it will attempt to process the template as test-dir/test-template Version: 1.0 instead of test-dir/test-template

To do:

• Add the rule in the Theme Review handbook to the Requirements page.
• Create unit tests
• Create new sniff
• Adjust existing WPCS / PHPCS sniff and send in PR upstream.
• Add existing sniffname sniff to the ruleset.