refactor: utilize PHP 7.4 arrow funciton

Signed-off-by: Jack Cherng <jfcherng@gmail.com>

Author: jfcherng

src/DiffHelper.php

@@ -55,12 +55,11 @@ public static function getRenderersInfo(): array
         $renderers = array_filter(
             $fileNames,
             // only normal class files are wanted
-            static function (string $fileName): bool {
-                return
-                    substr($fileName, 0, 8) !== 'Abstract'
-                    && substr($fileName, -9) !== 'Interface'
-                    && substr($fileName, -5) !== 'Trait';
-            },
+            static fn (string $fileName): bool => (
+                substr($fileName, 0, 8) !== 'Abstract'
+                && substr($fileName, -9) !== 'Interface'
+                && substr($fileName, -5) !== 'Trait'
+            ),
         );
 
         $info = [];

src/Renderer/Html/Combined.php

@@ -304,12 +304,15 @@ protected function mergeReplaceLines(string $oldLine, string $newLine): ?string
 
         // create a sorted merged parts array
         $mergedParts = array_merge($delParts, $insParts);
-        usort($mergedParts, static function (array $a, array $b): int {
+        usort(
+            $mergedParts,
             // first sort by "offsetClean", "order" then by "type"
-            return $a['offsetClean'] <=> $b['offsetClean']
-                ?: $a['order'] <=> $b['order']
-                ?: ($a['type'] === SequenceMatcher::OP_DEL ? -1 : 1);
-        });
+            static fn (array $a, array $b): int => (
+                $a['offsetClean'] <=> $b['offsetClean']
+                    ?: $a['order'] <=> $b['order']
+                    ?: ($a['type'] === SequenceMatcher::OP_DEL ? -1 : 1)
+            ),
+        );
 
         // insert merged parts into the cleaned line
         foreach (ReverseIterator::fromArray($mergedParts) as $part) {