Fix the issues reported by phpcs

+  /**
+   * Constructs the controller exampĺe.
+   *
+   * @param Drupal\libraries\ExternalLibrary\LibraryManager $libraryManager
+   *   The library manager.
+   */
+  public function __construct(LibraryManager $libraryManager) {
+    $this->libraryManager = $libraryManager;
+  }

The short description for a class constructor must include the class name and its namespace.

   /**
    * Injects BookManager Service.
    */
   public static function create(ContainerInterface $container) {
-    return new static();
+    return new static(
+        $container->get('libraries.manager'),
+    );
   }

The documentation comment for that method is simply {@inheritdoc}.

   /**
    * Loads a specified library (variant) for testing.
    *
    * JavaScript and CSS files can be checked directly by SimpleTest, so we only
-   * need to manually check for PHP files. We provide information about the loaded
-   * JavaScript and CSS files for easier debugging. See example/README.txt for
-   * more information.
+   * need to manually check for PHP files. We provide information about the
+   * loaded JavaScript and CSS files for easier debugging.
+   * See example/README.txt for more information.
    */
   private function buildPage($library, $variant = NULL) {

Parameters and return value are not described.

-          // $filepath = str_replace('index.php/', '', $filepath);
+          // $filepath = str_replace('index.php/', '', $filepath);.

Periods are not added to commented out code, since code is not a sentence.

         'type' => 'external',
         'data' => 'http://example.com/example.css',
         'version' => '1.0.0',
-      ]],
+      ],
+      ],

The last two lines are not correctly indented.

-      ->set('global_locators', [['id' => 'uri', 'configuration' => ['uri' => 'asset://']]])
+      ->set('global_locators', [[
+        'id' => 'uri',
+        'configuration' => ['uri' => 'asset://'],
+      ],
+      ])
       ->save();

Lines are allowed to be longer than 80 characters, when they are more readable. The changed code is not more readable than the existing code.

    * @return string
+   *   returns the library type id string.

The return value description must not start with returns nor include the return type.
id is also misspelled.

Let me work on #22.

When I am applying patch 16 on 8.x-3.x version it is showing me below error

sourabhjain@LPT-SOURABH libraries % git apply 3257291-16.patch.txt 
error: patch failed: tests/src/Functional/LibrariesWebTest.php:196
error: tests/src/Functional/LibrariesWebTest.php: patch does not apply

Please update the patch against the version number or correct the version number in ticket.

Rerolled patch #16, please review it.

Thanks!

Let me work on #22.

Fixed the #22 issues. Please review.

Hi, patch #28 applied cleanly, but left with minor errors.

FILE: C:\Users\Nisha\Contribution\libraries\tests\src\Functional\LibrariesWebTest.php
-------------------------------------------------------------------------------------------------------
FOUND 2 ERRORS AFFECTING 2 LINES
-------------------------------------------------------------------------------------------------------
 280 | ERROR | Public method name "LibrariesWebTest::_testLibrariesLoad" is not in lowerCamel format
 411 | ERROR | Public method name "LibrariesWebTest::_testLibrariesOutput" is not in lowerCamel format
-------------------------------------------------------------------------------------------------------

Time: 1.7 secs; Memory: 14MB

Patch #30 applied cleanly and addresses all the issues mentioned in #22.

Let's create a MR from the existing issue fork.