Generic/UpperCaseConstantName: improve code coverage

Includes updating a sniff code comment to better describe what it does.
Some of the cases described were not covered by tests before the changes
in this commit.

Author: rodrigoprimo

src/Standards/Generic/Sniffs/NamingConventions/UpperCaseConstantNameSniff.php

@@ -108,7 +108,10 @@ public function process(File $phpcsFile, $stackPtr)
             return;
         }
 
-        // The next non-empty token must be the constant name.
+        // Bow out if next non-empty token after the opening parenthesis is not a string (the
+        // constant name). This could happen when live coding, if the constant is a variable or an
+        // expression, or if handling a first-class callable or a function definition outside the
+        // global scope.
         $constPtr = $phpcsFile->findNext(Tokens::$emptyTokens, ($openBracket + 1), null, true);
         if ($constPtr === false || $tokens[$constPtr]['code'] !== T_CONSTANT_ENCAPSED_STRING) {
             return;

src/Standards/Generic/Tests/NamingConventions/UpperCaseConstantNameUnitTest.1.inc

@@ -5,7 +5,7 @@ namespace foo\bar;
 namespace bar\foo\baz;
 
 define('VALID_NAME', true);
-define('invalidName', true);
+DEFINE('invalidName', true);
 define("VALID_NAME", true);
 define("invalidName", true);
 define('bar\foo\baz\VALID_NAME_WITH_NAMESPACE', true);
@@ -37,9 +37,9 @@ class TypedConstants {
     const MISSING_VALUE; // Parse error.
     const MyClass MYCONST = new MyClass;
     const int VALID_NAME = 0;
-    const INT invalid_name = 0;
+    final public const INT invalid_name = 0;
     const FALSE false = false; // Yes, false can be used as a constant name, don't ask.
-    const array ARRAY = array(); // Same goes for array.
+    final protected const array ARRAY = array(); // Same goes for array.
 }
 
 define /* comment */ ( /* comment */ 'CommentsInUnconventionalPlaces', 'value' );
@@ -67,3 +67,16 @@ class MyClass {}
     define('some param')
 ]
 class MyClass {}
+
+const MixedCase = 1;
+
+define('lower_case_name', 'value');
+define($var, 'sniff should bow out');
+define(constantName(), 'sniff should bow out');
+define($obj->constantName(), 'sniff should bow out');
+define(MyClass::constantName(), 'sniff should bow out');
+define(condition() ? 'name1' : 'name2', 'sniff should bow out');
+
+// Valid if outside the global namespace. Sniff should bow out.
+function define($param) {}
+$callable = define(...);

src/Standards/Generic/Tests/NamingConventions/UpperCaseConstantNameUnitTest.3.inc

@@ -0,0 +1,7 @@
+<?php
+
+// Intentional parse error (missing opening parenthesis).
+// This should be the only test in this file.
+// Testing that the sniff is *not* triggered.
+
+define

src/Standards/Generic/Tests/NamingConventions/UpperCaseConstantNameUnitTest.4.inc

@@ -0,0 +1,7 @@
+<?php
+
+// Intentional parse error (missing constant name).
+// This should be the only test in this file.
+// Testing that the sniff is *not* triggered.
+
+const =

src/Standards/Generic/Tests/NamingConventions/UpperCaseConstantNameUnitTest.php

@@ -46,6 +46,8 @@ public function getErrorList($testFile='')
                 41 => 1,
                 45 => 1,
                 51 => 1,
+                71 => 1,
+                73 => 1,
             ];
         default:
             return [];