Enforce accepted values for the `type` attribute of the `<exclude-pattern>` and `<include-pattern>` tags

[rodrigoprimo]

Is your feature request related to a problem?

While reviewing #705 (review), I noticed that in the code documentation, PHPCS specifies that there are two possible values for the type attribute of the <exclude-pattern> and <include-pattern> tags that can be used in a ruleset file: absolute and relative.

PHP_CodeSniffer/src/Ruleset.php

Lines 48 to 57 in 9c8f30f

	/**
	* A list of regular expressions used to ignore specific sniffs for files and folders.
	*
	* Is also used to set global exclude patterns.
	* The key is the regular expression and the value is the type
	* of ignore pattern (absolute or relative).
	*
	* @var array<string, array>
	*/
	public $ignorePatterns = [];

PHP_CodeSniffer/src/Ruleset.php

Lines 59 to 68 in 9c8f30f

	/**
	* A list of regular expressions used to include specific sniffs for files and folders.
	*
	* The key is the sniff code and the value is an array with
	* the key being a regular expression and the value is the type
	* of ignore pattern (absolute or relative).
	*
	* @var array<string, array<string, string>>
	*/
	public $includePatterns = [];

But the code does not validate that one of those values is passed and any value is accepted:

PHP_CodeSniffer/src/Ruleset.php

Line 1232 in 9c8f30f

$this->ignorePatterns[$code][(string) $pattern] = (string) $pattern['type'];

PHP_CodeSniffer/src/Ruleset.php

Line 1258 in 9c8f30f

$this->includePatterns[$code][(string) $pattern] = (string) $pattern['type'];

Adding the following to a ruleset.xml file, will add a exclude pattern (called ignore pattern in the code) with the type InvalidValue:

<exclude-pattern type="InvalidValue">./vendor/*</exclude-pattern>

Describe the solution you'd like

PHPCS should validate the values passed to the type attribute and warn users if an invalid value is passed.

Additional context (optional)

• I have read the Contribution Guidelines and this is not a support question.
• I intend to create a pull request to implement this feature.

[rodrigoprimo]

@jrfnl, I started investigating a solution for this issue, but found a few things that I would like to check with you before proceeding.

Type for Ruleset::$includePatterns

I noticed that despite the code documentation for Ruleset::$includePatterns mentioning that the type of each entry can be either absolute or relative, it seems that the type is not utilized anywhere. Or at least, I was not able to find where it is used.

As far as I can see, the type is used only for Ruleset::$ignorePatterns when processing global patterns in src/Filters/Filter.php#L249. The type is ignored when processing sniff-specific ignore and include patterns (src/Ruleset.php#L1555-L1563).

The wiki does mention that include patterns are always absolute (https://github.com/PHPCSStandards/PHP_CodeSniffer/wiki/Annotated-Ruleset):

Please note that all sniff-specific include patterns are checked using absolute paths.

I wonder if, instead of enforcing the accepted values for the type attribute of the include-pattern tag, the code should be updated to remove, where possible, references to the type of the include-pattern? Maybe the ruleset XML schema should be updated to remove the type attribute from the include-pattern tag?

Accepted values for the type attribute

When I opened this issue, I saw the code documentation mentioned in the issue description, which states that the value of the type attribute can be either absolute or relative. But now, checking the ruleset XML schema, I noticed that it only accepts relative as the value for this attribute. absolute is used by default if no value is passed, but it is not accepted as an explicit value in the XML schema definition. I understand that it is not necessary to explicitly use absolute as it is the default value, but I fail to see the reason to not accept it. Should the XML schema definition be updated? If not, should this issue be updated to only accept relative as an explicit value for the type attribute?