PEAR/FunctionComment: prevent false positives with attributes

PHP 8.0+ attributes can be placed between a docblock and the function declaration it applies to.

The `PEAR.Commenting.FunctionComment` sniff - and by extension the `Squiz.Commenting.FunctionComment` sniff - did not yet take this into account.

This would result in a false positive `Missing doc comment for function ... ` error.

Resolving that error though, would result in a new `There must be no blank lines after the function comment` error, so the blank line check also needed to be fixed.

With the current fix, blank lines between the docblock and the function declaration are still not allowed, but non-blank lines between the two (i.e. lines containing attributes) will be ignored.

Only one "no blank lines between" error will be thrown per function declaration.

src/Standards/PEAR/Sniffs/Commenting/FunctionCommentSniff.php

@@ -68,11 +68,25 @@ public function process(File $phpcsFile, $stackPtr)
             return;
         }
 
-        $tokens   = $phpcsFile->getTokens();
-        $ignore   = Tokens::$methodPrefixes;
-        $ignore[] = T_WHITESPACE;
+        $tokens = $phpcsFile->getTokens();
+        $ignore = Tokens::$methodPrefixes;
+        $ignore[T_WHITESPACE] = T_WHITESPACE;
+
+        for ($commentEnd = ($stackPtr - 1); $commentEnd >= 0; $commentEnd--) {
+            if (isset($ignore[$tokens[$commentEnd]['code']]) === true) {
+                continue;
+            }
+
+            if ($tokens[$commentEnd]['code'] === T_ATTRIBUTE_END
+                && isset($tokens[$commentEnd]['attribute_opener']) === true
+            ) {
+                $commentEnd = $tokens[$commentEnd]['attribute_opener'];
+                continue;
+            }
+
+            break;
+        }
 
-        $commentEnd = $phpcsFile->findPrevious($ignore, ($stackPtr - 1), null, true);
         if ($tokens[$commentEnd]['code'] === T_COMMENT) {
             // Inline comments might just be closing comments for
             // control structures or functions instead of function comments
@@ -106,8 +120,19 @@ public function process(File $phpcsFile, $stackPtr)
         }
 
         if ($tokens[$commentEnd]['line'] !== ($tokens[$stackPtr]['line'] - 1)) {
-            $error = 'There must be no blank lines after the function comment';
-            $phpcsFile->addError($error, $commentEnd, 'SpacingAfter');
+            for ($i = ($commentEnd + 1); $i < $stackPtr; $i++) {
+                if ($tokens[$i]['column'] !== 1) {
+                    continue;
+                }
+
+                if ($tokens[$i]['code'] === T_WHITESPACE
+                    && $tokens[$i]['line'] !== $tokens[($i + 1)]['line']
+                ) {
+                    $error = 'There must be no blank lines after the function comment';
+                    $phpcsFile->addError($error, $commentEnd, 'SpacingAfter');
+                    break;
+                }
+            }
         }
 
         $commentStart = $tokens[$commentEnd]['comment_opener'];

src/Standards/PEAR/Tests/Commenting/FunctionCommentUnitTest.inc

@@ -429,3 +429,50 @@ public function ignored() {
 }
 
 // phpcs:set PEAR.Commenting.FunctionComment specialMethods[] __construct,__destruct
+
+class Something implements JsonSerializable {
+    /**
+     * Single attribute.
+     *
+     * @return mixed
+     */
+    #[ReturnTypeWillChange]
+    public function jsonSerialize() {}
+
+    /**
+     * Multiple attributes.
+     *
+     * @return Something
+     */
+    #[AttributeA]
+    #[AttributeB]
+    public function methodName() {}
+
+    /**
+     * Blank line between docblock and attribute.
+     *
+     * @return mixed
+     */
+
+    #[ReturnTypeWillChange]
+    public function blankLineDetectionA() {}
+
+    /**
+     * Blank line between attribute and function declaration.
+     *
+     * @return mixed
+     */
+    #[ReturnTypeWillChange]
+
+    public function blankLineDetectionB() {}
+
+    /**
+     * Blank line between both docblock and attribute and attribute and function declaration.
+     *
+     * @return mixed
+     */
+
+    #[ReturnTypeWillChange]
+
+    public function blankLineDetectionC() {}
+}

src/Standards/PEAR/Tests/Commenting/FunctionCommentUnitTest.inc.fixed

@@ -429,3 +429,50 @@ public function ignored() {
 }
 
 // phpcs:set PEAR.Commenting.FunctionComment specialMethods[] __construct,__destruct
+
+class Something implements JsonSerializable {
+    /**
+     * Single attribute.
+     *
+     * @return mixed
+     */
+    #[ReturnTypeWillChange]
+    public function jsonSerialize() {}
+
+    /**
+     * Multiple attributes.
+     *
+     * @return Something
+     */
+    #[AttributeA]
+    #[AttributeB]
+    public function methodName() {}
+
+    /**
+     * Blank line between docblock and attribute.
+     *
+     * @return mixed
+     */
+
+    #[ReturnTypeWillChange]
+    public function blankLineDetectionA() {}
+
+    /**
+     * Blank line between attribute and function declaration.
+     *
+     * @return mixed
+     */
+    #[ReturnTypeWillChange]
+
+    public function blankLineDetectionB() {}
+
+    /**
+     * Blank line between both docblock and attribute and attribute and function declaration.
+     *
+     * @return mixed
+     */
+
+    #[ReturnTypeWillChange]
+
+    public function blankLineDetectionC() {}
+}

src/Standards/PEAR/Tests/Commenting/FunctionCommentUnitTest.php

@@ -70,6 +70,9 @@ public function getErrorList()
             364 => 1,
             406 => 1,
             417 => 1,
+            455 => 1,
+            464 => 1,
+            473 => 1,
         ];
 
     }//end getErrorList()