fix: allow get_filenames() to follow symlinks

[colethorsen]

Description

While symlinks that are going directly to a file are followed, the RecursiveDirectoryIterator does not follow folder based symlinks without setting the proper flag.

new RecursiveDirectoryIterator($sourceDir, RecursiveDirectoryIterator::SKIP_DOTS),

to

new RecursiveDirectoryIterator($sourceDir, RecursiveDirectoryIterator::SKIP_DOTS | FilesystemIterator::FOLLOW_SYMLINKS),

Originally posted by @colethorsen in #8216 (comment)

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[kenjis]

There is no description for symlinks in the user guides.
http://www.codeigniter.com/userguide3/helpers/file_helper.html?highlight=get_filenames#get_filenames
https://codeigniter4.github.io/CodeIgniter4/helpers/filesystem_helper.html?highlight=get_filenames#get_filenames

In CI3:

$ ls -l
total 16
-rw-r--r--  1 kenji  staff  706 Nov 17 06:27 Welcome.php
-rw-r--r--  1 kenji  staff  141 Mar 17  2023 index.html
lrwxr-xr-x  1 kenji  staff    8 Nov 17 06:29 views -> ../views

	public function index()
	{
		$this->load->helper('file');
		var_dump(get_filenames(__DIR__));
	}

array(17) {
  [0] =>
  string(10) "index.html"
  [1] =>
  string(10) "index.html"
  [2] =>
  string(19) "welcome_message.php"
  [3] =>
  string(10) "index.html"
  [4] =>
  string(10) "index.html"
  [5] =>
  string(13) "error_php.php"
  [6] =>
  string(17) "error_general.php"
  [7] =>
  string(13) "error_404.php"
  [8] =>
  string(19) "error_exception.php"
  [9] =>
  string(12) "error_db.php"
  [10] =>
  string(10) "index.html"
  [11] =>
  string(13) "error_php.php"
  [12] =>
  string(17) "error_general.php"
  [13] =>
  string(13) "error_404.php"
  [14] =>
  string(19) "error_exception.php"
  [15] =>
  string(12) "error_db.php"
  [16] =>
  string(11) "Welcome.php"
}

[kenjis]

In CI4 develop:

$ ls -l
total 16
-rw-r--r--  1 kenji  staff  1579 Oct 27 16:48 BaseController.php
-rw-r--r--  1 kenji  staff   161 Nov 16 10:10 Home.php
lrwxr-xr-x  1 kenji  staff     8 Nov 17 06:31 Views -> ../Views

    public function index()
    {
        helper('filesystem');
        dd(get_filenames(APPPATH . 'Controllers/'));
    }

┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ get_filenames(...)                                                                                                                                       │
└──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
array (3) [
    0 => string (18) "BaseController.php"
    1 => string (8) "Home.php"
    2 => string (5) "Views"
]
════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════

[kenjis]

@colethorsen Thank you. This is a bug. Symlink folders also should be followed.

But this changes the behavior, so can you add a short description for it in the changelog?
https://github.com/codeigniter4/CodeIgniter4/blob/develop/user_guide_src/source/changelogs/v4.4.4.rst#breaking
And add a note something like "Prior to v4.4.4, due to a bug, this function did not follow symlink folders." in the get_filenames():
https://github.com/codeigniter4/CodeIgniter4/blob/develop/user_guide_src/source/helpers/filesystem_helper.rst#available-functions

Also we expect all code changes or bug-fixes to be accompanied by one or more tests added to our test suite to prove the code works. Can you add test code?

[colethorsen]

Also we expect all code changes or bug-fixes to be accompanied by one or more tests added to our test suite to prove the code works. Can you add test code?

It appears that vfsStream does not support testing symlinks bovigo/vfsStream#89 if you have any thoughts on how this should be tested alternatively let me know.

[kenjis]

--- a/tests/system/Helpers/FilesystemHelperTest.php
+++ b/tests/system/Helpers/FilesystemHelperTest.php
@@ -396,6 +396,31 @@ final class FilesystemHelperTest extends CIUnitTestCase
         $this->assertSame([], get_filenames(SUPPORTPATH . 'Files/shaker/'));
     }
 
+    public function testGetFilenamesWithSymlinks(): void
+    {
+        $targetDir = APPPATH . 'Language';
+        $linkDir   = APPPATH . 'Controllers/Language';
+        unlink($linkDir);
+        symlink($targetDir, $linkDir);
+
+        $targetFile = APPPATH . 'Common.php';
+        $linkFile   = APPPATH . 'Controllers/Common.php';
+        unlink($linkFile);
+        symlink($targetFile, $linkFile);
+
+        $this->assertSame([
+            0 => 'BaseController.php',
+            1 => 'Common.php',
+            2 => 'Home.php',
+            3 => 'Language',
+            4 => 'Validation.php',
+            5 => 'en',
+        ], get_filenames(APPPATH . 'Controllers'));
+
+        unlink($linkDir);
+        unlink($linkFile);
+    }
+
     public function testGetDirFileInfo(): void
     {
         $file = SUPPORTPATH . 'Files/baker/banana.php';

[kenjis]

Can you add a test?

[github-actions]

👋 Hi, @colethorsen!

We detected conflicts in your PR against the base branch 🙊
You may want to sync 🔄 your branch with upstream!

Ref: Syncing Your Branch

[kenjis]

Closed by #8298