Generic/[Lower|Upper]CaseConstant: handle FQN true/false/null

These are the only two sniffs explicitly targetting `true`, `false` and `null`.

This commit allows these sniffs to still function correctly on "fully qualified true/false/null" after the merge of 1020.

Includes tests.

Author: jrfnl

src/Standards/Generic/Sniffs/PHP/LowerCaseConstantSniff.php

@@ -60,6 +60,9 @@ public function register()
     {
         $targets = $this->targets;
 
+        // Allow for "fully qualified" true/false/null.
+        $targets[] = T_NAME_FULLY_QUALIFIED;
+
         // Register scope modifiers to filter out property type declarations.
         $targets  += Tokens::SCOPE_MODIFIERS;
         $targets[] = T_VAR;
@@ -95,6 +98,13 @@ public function process(File $phpcsFile, $stackPtr)
     {
         $tokens = $phpcsFile->getTokens();
 
+        // If this is a fully qualified name, check if it is FQN true/false/null.
+        if ($tokens[$stackPtr]['code'] === T_NAME_FULLY_QUALIFIED
+            && $this->isFQNTrueFalseNull($phpcsFile, $stackPtr) === false
+        ) {
+            return;
+        }
+
         // Skip over potential type declarations for constants.
         if ($tokens[$stackPtr]['code'] === T_CONST) {
             // Constant must always have a value assigned to it, so we can just look for the assignment
@@ -178,7 +188,10 @@ public function process(File $phpcsFile, $stackPtr)
                 }
 
                 for ($i = $param['default_token']; $i < $paramEnd; $i++) {
-                    if (isset($this->targets[$tokens[$i]['code']]) === true) {
+                    if (isset($this->targets[$tokens[$i]['code']]) === true
+                        || ($tokens[$i]['code'] === T_NAME_FULLY_QUALIFIED
+                        && $this->isFQNTrueFalseNull($phpcsFile, $i) === true)
+                    ) {
                         $this->processConstant($phpcsFile, $i);
                     }
                 }
@@ -194,6 +207,28 @@ public function process(File $phpcsFile, $stackPtr)
     }//end process()
 
 
+    /**
+     * Check if a fully qualified name is a fully qualified true/false/null.
+     *
+     * @param \PHP_CodeSniffer\Files\File $phpcsFile The file being scanned.
+     * @param int                         $stackPtr  The position of the T_NAME_FULLY_QUALIFIED token in the
+     *                                               stack passed in $tokens.
+     *
+     * @return bool
+     */
+    protected function isFQNTrueFalseNull(File $phpcsFile, $stackPtr)
+    {
+        $tokens = $phpcsFile->getTokens();
+
+        // Check for fully qualified true/false/null only.
+        $compareReadyKeyword = strtolower($tokens[$stackPtr]['content']);
+        return ($compareReadyKeyword === '\true'
+            || $compareReadyKeyword === '\false'
+            || $compareReadyKeyword === '\null');
+
+    }//end isFQNTrueFalseNull()
+
+
     /**
      * Processes a non-type declaration constant.
      *

src/Standards/Generic/Tests/PHP/LowerCaseConstantUnitTest.1.inc

@@ -160,3 +160,7 @@ class SkipOverPHP84FinalProperties {
     final MyType|FALSE $propA;
     private static final NULL|MyClass $propB;
 }
+
+$a = \NULL;
+$a = \falSe;
+$a = \True;

src/Standards/Generic/Tests/PHP/LowerCaseConstantUnitTest.1.inc.fixed

@@ -160,3 +160,7 @@ class SkipOverPHP84FinalProperties {
     final MyType|FALSE $propA;
     private static final NULL|MyClass $propB;
 }
+
+$a = \null;
+$a = \false;
+$a = \true;

src/Standards/Generic/Tests/PHP/LowerCaseConstantUnitTest.php

@@ -66,6 +66,9 @@ public function getErrorList($testFile='')
                 129 => 1,
                 149 => 1,
                 153 => 1,
+                164 => 1,
+                165 => 1,
+                166 => 1,
             ];
 
         default:

src/Standards/Generic/Tests/PHP/UpperCaseConstantUnitTest.inc

@@ -105,3 +105,7 @@ class SkipOverPHP84FinalProperties {
     final MyType|false $propA;
     private static final null|MyClass $propB;
 }
+
+$a = \null;
+$a = \falSe;
+$a = \True;

src/Standards/Generic/Tests/PHP/UpperCaseConstantUnitTest.inc.fixed

@@ -105,3 +105,7 @@ class SkipOverPHP84FinalProperties {
     final MyType|false $propA;
     private static final null|MyClass $propB;
 }
+
+$a = \NULL;
+$a = \FALSE;
+$a = \TRUE;

src/Standards/Generic/Tests/PHP/UpperCaseConstantUnitTest.php

@@ -31,27 +31,30 @@ final class UpperCaseConstantUnitTest extends AbstractSniffTestCase
     public function getErrorList()
     {
         return [
-            7  => 1,
-            10 => 1,
-            15 => 1,
-            16 => 1,
-            23 => 1,
-            26 => 1,
-            31 => 1,
-            32 => 1,
-            39 => 1,
-            42 => 1,
-            47 => 1,
-            48 => 1,
-            70 => 1,
-            71 => 1,
-            85 => 1,
-            87 => 1,
-            88 => 1,
-            90 => 2,
-            92 => 2,
-            93 => 1,
-            98 => 2,
+            7   => 1,
+            10  => 1,
+            15  => 1,
+            16  => 1,
+            23  => 1,
+            26  => 1,
+            31  => 1,
+            32  => 1,
+            39  => 1,
+            42  => 1,
+            47  => 1,
+            48  => 1,
+            70  => 1,
+            71  => 1,
+            85  => 1,
+            87  => 1,
+            88  => 1,
+            90  => 2,
+            92  => 2,
+            93  => 1,
+            98  => 2,
+            109 => 1,
+            110 => 1,
+            111 => 1,
         ];
 
     }//end getErrorList()