Review the WordPressVIPMinimum.Performance.LowExpiryCacheTime sniff

[jrfnl]

Review the WordPressVIPMinimum.Performance.LowExpiryCacheTime sniff for the following in as far as relevant to that sniff:

• Code style independent sniffing / Correct handling of quirky code
  Typical things to add tests for and verify correct handling of:
  • Nested function/closure declarations
  • Nested class declarations
  • Comments in unexpected places
  • Variables being assigned to via list statements
  • Multiline text strings
  • Text strings provided via heredoc/nowdoc
  • Use of short open tags
  • Using PHP close tag as end of statement
  • Inline control structures (without braces)
• Code simplifications which can be made using PHPCSUtils
• Sniff stability improvements which can be made using PHPCSUtils
• Correct handling of modern PHP code
  Typical things to add tests for and verify correct handling of (where applicable):
  • PHP 5.0 Try/catch/finally (PHP 5.5) and exceptions
  • PHP 5.3 Namespaced code vs code in the global namespace
  • PHP 5.3 Use import statements, incl aliasing
  • PHP 5.3 Short ternaries
  • PHP 5.3 Closures, incl closure use
  • PHP 5.4 Short arrays
  • PHP 5.5 Class name resolution using ::class
  • PHP 5.5 List in foreach
  • PHP 5.5/7.0 Generators using yield and yield from
  • PHP 5.6 Constant scalar expressions
  • PHP 5.6 Importing via use function/const
  • PHP 7.0 Null coalesce
  • PHP 7.0 Anonymous classes
  • PHP 7.0 Scalar and return type declarations
  • PHP 7.0 Group use statements
  • PHP 7.1 Short lists
  • PHP 7.1 Keyed lists
  • PHP 7.1 Multi-catch
  • PHP 7.1 Nullable types
  • PHP 7.3 List reference assignments
  • PHP 7.4 arrow functions
  • PHP 7.4 numeric literals with underscores
  • PHP 7.4 null coalesce equals
  • PHP 7.4 Typed properties
  • Various versions: trailing comma's in function calls, group use, function declarations, closure use etc

Other:

• Review violation error vs warning
• Review violation severity
• Review violation message, consider adding a link
• Check open issues related to the sniff
• Review PHPDoc comments

Sniff basics, but changes need to be lined up for next major release:

• Inappropriate use of public properties (Audit Public Sniff Properties #234)
• Modular error codes (unique error code for each distinct message)

Once PHPCS/PHPCSUtils supports this:

• PHP 8.0 Constructor property promotion
• PHP 8.0 Union types
• PHP 8.0 match expressions
• PHP 8.0 Nullsafe operator
• PHP 8.0 Named arguments
• PHP 8.0 Single token namespaced names

[jrfnl]

While working on #572, a number of other issues with the sniff caught my eye. A few of these will be addressed now in combination with #572, but there are also issues which are better left for when PHPCSUtils is in place.

Will be addressed now:

• Handling of comments in the parameter.
• Handling of 0 and values which evaluate to 0 being passed. 0 is the default value and will translate in the wp_cache_set() function internally as "no expiration".
• One of the WP predefined time constants being passed on its own.

Edge cases, can be addressed later using Utils:

• Prevent false positives for namespaced functions with the same name imported via a use function statement.
• Prevent incorrect identification of namespaced constants with the same name as one of the WP time constants imported via a use const statement.
• Handling of non-decimal numbers.
• Handling of PHP 7.4 numeric literals with underscores.
• Handling of other integer constants with known values.
• More complex calculation handling (isNumericCalculation).
• Handling of PHP 8.0 namespace names (as single token) for both the function name recognition as well as the WP time constant recognition.

Note: this is not a complete review, just notes as reminder for later.

[jrfnl]

Related open issues: #408 (PR #445)

For some more example code, see: https://wpdirectory.net/search/01EM5DTRB0VBNB64F3HTGH5D97