PHPCS 3.4.0: use File::getMethodProperties() / 'has_body'

[jrfnl]

Rationale

WPCS includes a number of sniffs which examine function declarations.

Functions can be declared with or without body:

// Standard, with body:
function something( $param ) {
    /* function body */
}

// Abstract or stub without body:
class Foo {
    abstract function Bar( $param );
}

interface Foo {
    function Bar( $param );
}

In PHPCS 3.4.0, the output of the upstream File::getMethodProperties() method has been enhanced to contain a 'has_body' array key.

It should be examined if existing code in WPCS:

1. Takes function declarations without body well enough into account.
2. Could be simplified by using the enhanced upstream method.

References

• Upstream (merged) PR: https://github.com/squizlabs/PHP_CodeSniffer/pull/2148

Action Checklist

Once WPCS ups the minimum required PHPCS version to 3.4.0:

• Check all sniffs which deal with the T_FUNCTION token/ which deal with function declarations to see:
  • [ ] If they correctly deal with abstract methods / interface methods.
  • [ ] Whether the sniff code could be simplified by using the new has_body key in the output from the File::getMethodProperties() method.

[vdwijngaert]

I can confirm that for the WordPress.WhiteSpace.ControlStructureSpacing sniff, the NoSpaceAfterOpenParenthesis and NoSpaceBeforeCloseParenthesis violations are not picked up for abstract methods and interface methods. Same thing for T_FN aka arrow functions.

The spacing issue in the following code does not get reported:

// Abstract or stub without body:
class Foo {
    abstract function Bar( $param);
// ------------------------------^
}

interface Foo {
    function Bar( $param);
// ---------------------^
}

$bar = fn( $param) => $param;
// --------------^

As far as I can tell, the reason for this, is that in ControlStructureSpacingSniff, we do an early return if we cannot find a scope closer.

Having something like Sniff::is_method_with_body() might help, but there's probably a ton of more code that can be simplified thanks to these new additions...

    /**
     * @param int $stackPtr The index of the token in the stack. This must point to
     *                      either a T_FUNCTION, T_CLOSURE, T_USE, or T_FN token.
     * 
     * @since 3.0.0
     *
     * @return bool Whether the token is a function call with a body.
     */
    protected function is_method_with_body( $stackPtr ) {
        try {
            $method_parameters = $this->phpcsFile->getMethodParameters( $stackPtr );

            return $method_parameters['has_body'] === true;
        } catch( \PHP_CodeSniffer\Exceptions\RuntimeException $e ) {
            return false;
        }
    }

[jrfnl]

@vdwijngaert Your issue sounds more closely related to #1101...

[GaryJones]

Once WPCS ups the minimum required PHPCS version to 3.4.0

WPCS 3.0 will have PHPCS 3.7.2 as the minimum.

[jrfnl]

I think we can actually close this issue. I just double-checked, but WPCS 3.0.0 won't contain any sniffs which would benefit from that key.