[BUGFIX] Not include defer files to concatenateJs

Deferred files should not be concatenated. They are now
output as a single script.

Resolves: #90208
Releases: master, 9.5
Change-Id: I17c84b41acd445db6ee261bade69fddd32ca7380
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63779
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Susanne Moog <look@susi.dev>
Reviewed-by: Susanne Moog <look@susi.dev>

typo3/sysext/core/Classes/Resource/ResourceCompressor.php

@@ -175,7 +175,7 @@ public function concatenateJsFiles(array $jsFiles)
         $filesToInclude = [];
         foreach ($jsFiles as $key => $fileOptions) {
             // invalid section found or no concatenation allowed, so continue
-            if (empty($fileOptions['section']) || !empty($fileOptions['excludeFromConcatenation'])) {
+            if (empty($fileOptions['section']) || !empty($fileOptions['excludeFromConcatenation']) || !empty($fileOptions['defer'])) {
                 continue;
             }
             if (!isset($filesToInclude[$fileOptions['section']])) {

typo3/sysext/core/Tests/Unit/Resource/ResourceCompressorTest.php

@@ -685,4 +685,25 @@ public function getFilenamesFromMainDirInBackendContextWithSubFolder(string $fil
         $relativeToRootPath = $subject->_call('getFilenameFromMainDir', $filename);
         self::assertSame($expected, $relativeToRootPath);
     }
+
+    /**
+     * @test
+     */
+    public function deferJavascriptIsNotConcatenated(): void
+    {
+        $fileName = 'fooFile.js';
+        $concatenatedFileName = 'merged_' . $fileName;
+        $testFileFixture = [
+            $fileName => [
+                'file' => $fileName,
+                'defer' => true,
+                'section' => 'top',
+            ]
+        ];
+
+        $result = $this->subject->concatenateJsFiles($testFileFixture);
+
+        self::assertArrayNotHasKey($concatenatedFileName, $result);
+        self::assertTrue($result[$fileName]['defer']);
+    }
 }