Use more specific string functions

Author: sebastianbergmann

tests/Output/Integration/UnifiedDiffOutputBuilderIntegrationTest.php

@@ -20,7 +20,7 @@
 use function preg_split;
 use function realpath;
 use function sprintf;
-use function strpos;
+use function str_contains;
 use function unlink;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\Attributes\DataProvider;
@@ -49,7 +49,7 @@ public static function provideDiffWithLineNumbers(): array
             UnifiedDiffOutputBuilderDataProvider::provideDiffWithLineNumbers(),
             static function ($key)
             {
-                return !is_string($key) || false === strpos($key, 'non_patch_compat');
+                return !is_string($key) || !str_contains($key, 'non_patch_compat');
             },
             ARRAY_FILTER_USE_KEY
         );

tests/Utils/UnifiedDiffAssertTrait.php

@@ -15,8 +15,8 @@
 use function preg_match;
 use function preg_split;
 use function sprintf;
+use function str_starts_with;
 use function strlen;
-use function strpos;
 use function substr;
 use RuntimeException;
 use UnexpectedValueException;
@@ -52,8 +52,8 @@ public function assertValidUnifiedDiffFormat(string $diff): void
             $this->unifiedDiffAssertLinePrefix($lines[0], 'Line 1.');
             $this->unifiedDiffAssertLinePrefix($lines[1], 'Line 2.');
 
-            if ('---' === substr($lines[0], 0, 3)) {
-                if ('+++' !== substr($lines[1], 0, 3)) {
+            if (str_starts_with($lines[0], '---')) {
+                if (!str_starts_with($lines[1], '+++')) {
                     throw new UnexpectedValueException(sprintf("Line 1 indicates a header, so line 2 must start with \"+++\".\nLine 1: \"%s\"\nLine 2: \"%s\".", $lines[0], $lines[1]));
                 }
 
@@ -211,7 +211,7 @@ private function unifiedDiffAssertStrLength(string $line, int $min, string $mess
      */
     private function unifiedDiffAssertHeaderLine(string $line, string $start, string $message): void
     {
-        if (0 !== strpos($line, $start)) {
+        if (!str_starts_with($line, $start)) {
             throw new UnexpectedValueException(sprintf('Expected header line to start with "%s", got "%s". %s', $start . ' ', $line, $message));
         }