Issue #2770983 by tstoeckler: Make Libraries API work on Windows.

CHANGELOG.txt

 
 Libraries 8.x-3.x, xxxx-xx-xx
 -----------------------------
+#2770983 by tstoeckler: Make Libraries API work on Windows.
+#2770983 by tstoeckler: Allow libraries to be symlinked to their right place.
 #2756265 by rajeshwari10: Replace deprecated usage of SafeMarkup::checkPlain().
 #2742333 by jrockowitz: Fix missing @group in LinePatternDetectorTest
 by tstoeckler: Document plugin alter hooks

src/ExternalLibrary/PhpFile/PhpFileLibrary.php

@@ -57,7 +57,7 @@ class PhpFileLibrary extends LibraryBase implements PhpFileLibraryInterface {
 
     $processed_files = [];
     foreach ($this->files as $file) {
-      $processed_files[] = $this->getLocalPath() . DIRECTORY_SEPARATOR . $file;
+      $processed_files[] = $this->getLocalPath() . '/' . $file;
     }
     return $processed_files;
   }

tests/src/Kernel/ExternalLibrary/PhpFile/PhpFileLibraryTest.php

@@ -39,7 +39,7 @@ class PhpFileLibraryTest extends LibraryTypeKernelTestBase {
     /** @var \Drupal\libraries\ExternalLibrary\PhpFile\PhpFileLibrary $library */
     $library = $this->getLibrary();
     $this->assertTrue($library->isInstalled());
-    $library_path = $this->modulePath . DIRECTORY_SEPARATOR . 'tests/libraries/test_php_file_library';
+    $library_path = $this->modulePath . '/tests/libraries/test_php_file_library';
     $this->assertEquals($library_path, $library->getLocalPath());
     $this->assertEquals(["$library_path/test_php_file_library.php"], $library->getPhpFiles());
   }