fix(tests): Raise Code Coverage 100%.

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## 0.2.0 Under development
 
 - Enh #6: Refactor codebase to improve performance (@terabytesoftw)
+- Bug #8: Raise Code Coverage `100%` (@terabytesoftw)
 
 ## 0.1.0 February 25, 2024
 

src/WordCaseConverter.php

@@ -8,7 +8,6 @@
 use function ltrim;
 use function preg_match;
 use function preg_replace;
-use function preg_split;
 use function strtolower;
 use function ucfirst;
 

tests/Support/MockerExtension.php

@@ -63,6 +63,10 @@ public static function load(): void
                 'namespace' => 'PHPForge\\Helper',
                 'name' => 'random_int',
             ],
+            [
+                'namespace' => 'PHPForge\\Helper',
+                'name' => 'preg_split',
+            ],
             [
                 'namespace' => 'PHPForge\\Helper',
                 'name' => 'str_contains',

tests/WordCaseConverterTest.php

@@ -18,6 +18,7 @@
  * - Ensures `snakeToCamel()` returns early without calling `explode()` when no underscore exists.
  * - Ensures `snakeToCamel()` returns expected camel case values.
  * - Ensures `toTitleWords()` formats snake case, camel case, and uppercase values consistently.
+ * - Ensures `toTitleWords()` falls back to `ucfirst()` when `preg_split()` fails.
  *
  * @copyright Copyright (C) 2026 Terabytesoftw.
  * @license https://opensource.org/license/bsd-3-clause BSD 3-Clause License.
@@ -74,4 +75,20 @@ public function testToTitleWords(string $input, string $expected, string $messag
             $message,
         );
     }
+
+    public function testToTitleWordsFallsBackWhenPregSplitFails(): void
+    {
+        MockerState::addCondition(
+            'PHPForge\\Helper',
+            'preg_split',
+            ['/(?<=[a-z])(?=[A-Z])|_/', 'foo_bar', -1, 0],
+            false,
+        );
+
+        self::assertSame(
+            'Foo_bar',
+            WordCaseConverter::toTitleWords('foo_bar'),
+            "Should return ucfirst(input) when 'preg_split()' fails.",
+        );
+    }
 }