Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

namespace core;

use file_system_filedir;

defined('MOODLE_INTERNAL') || die();

global $CFG;

require_once($CFG->libdir . '/filestorage/file_system.php');

require_once($CFG->libdir . '/filestorage/file_system_filedir.php');

/**

 * Unit tests for file_system_filedir.

 *

 * @package   core

 * @category  test

 * @copyright 2017 Andrew Nicols <andrew@nicols.co.uk>

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 * @coversDefaultClass \file_system_filedir

 */

class file_system_filedir_test extends \advanced_testcase {

    /**

     * Shared test setUp.

     */

    public function setUp(): void {

        // Reset the file storage so that subsequent fetches to get_file_storage are called after

        // configuration is prepared.

        get_file_storage(true);

    }

    /**

     * Shared teset tearDown.

     */

    public function tearDown(): void {

        // Reset the file storage so that subsequent tests will use the standard file storage.

        get_file_storage(true);

    }

    /**

     * Helper function to help setup and configure the virtual file system stream.

     *

     * @param   array $filedir Directory structure and content of the filedir

     * @param   array $trashdir Directory structure and content of the sourcedir

     * @param   array $sourcedir Directory structure and content of a directory used for source files for tests

     * @return  \org\bovigo\vfs\vfsStream

     */

    protected function setup_vfile_root($filedir = [], $trashdir = [], $sourcedir = null) {

        global $CFG;

        $this->resetAfterTest();

        $content = [];

        if ($filedir !== null) {

            $content['filedir'] = $filedir;

        }

        if ($trashdir !== null) {

            $content['trashdir'] = $trashdir;

        }

        if ($sourcedir !== null) {

            $content['sourcedir'] = $sourcedir;

        }

        $vfileroot = \org\bovigo\vfs\vfsStream::setup('root', null, $content);

        $CFG->filedir = \org\bovigo\vfs\vfsStream::url('root/filedir');

        $CFG->trashdir = \org\bovigo\vfs\vfsStream::url('root/trashdir');

        return $vfileroot;

    }

    /**

     * Helper to create a stored file objectw with the given supplied content.

     *

     * @param   string  $filecontent The content of the mocked file

     * @param   string  $filename The file name to use in the stored_file

     * @param   array   $mockedmethods A list of methods you intend to override

     *                  If no methods are specified, only abstract functions are mocked.

     * @return \stored_file

     */

    protected function get_stored_file($filecontent, $filename = null, $mockedmethods = []) {

        $contenthash = \file_storage::hash_from_string($filecontent);

        if (empty($filename)) {

            $filename = $contenthash;

        }

        $file = $this->getMockBuilder(\stored_file::class)

            ->onlyMethods($mockedmethods)

            ->setConstructorArgs([

                get_file_storage(),

                (object) [

                    'contenthash' => $contenthash,

                    'filesize' => strlen($filecontent),

                    'filename' => $filename,

                ]

            ])

            ->getMock();

        return $file;

    }

    /**

     * Get a testable mock of the file_system_filedir class.

     *

     * @param   array   $mockedmethods A list of methods you intend to override

     *                  If no methods are specified, only abstract functions are mocked.

     * @return \file_system

     */

    protected function get_testable_mock($mockedmethods = []) {

        $fs = $this->getMockBuilder(file_system_filedir::class)

            ->onlyMethods($mockedmethods)

            ->getMock();

        return $fs;

    }

    /**

     * Ensure that an appropriate error is shown when the filedir directory

     * is not writable.

     *

     * @covers ::__construct

     */

    public function test_readonly_filesystem_filedir(): void {

        $this->resetAfterTest();

        // Setup the filedir but remove permissions.

        $vfileroot = $this->setup_vfile_root(null);

        // Make the target path readonly.

        $vfileroot->chmod(0444)

            ->chown(\org\bovigo\vfs\vfsStream::OWNER_USER_2);

        // This should generate an exception.

        $this->expectException('file_exception');

        $this->expectExceptionMessageMatches(

            '/Cannot create local file pool directories. Please verify permissions in dataroot./');

        new file_system_filedir();

    }

    /**

     * Ensure that an appropriate error is shown when the trash directory

     * is not writable.

     *

     * @covers ::__construct

     */

    public function test_readonly_filesystem_trashdir(): void {

        $this->resetAfterTest();

        // Setup the trashdir but remove permissions.

        $vfileroot = $this->setup_vfile_root([], null);

        // Make the target path readonly.

        $vfileroot->chmod(0444)

            ->chown(\org\bovigo\vfs\vfsStream::OWNER_USER_2);

        // This should generate an exception.

        $this->expectException('file_exception');

        $this->expectExceptionMessageMatches(

            '/Cannot create local file pool directories. Please verify permissions in dataroot./');

        new file_system_filedir();

    }

    /**

     * Test that the standard Moodle warning message is put into the filedir.

     *

     * @covers ::__construct

     */

    public function test_warnings_put_in_place(): void {

        $this->resetAfterTest();

        $vfileroot = $this->setup_vfile_root(null);

        new file_system_filedir();

        $this->assertTrue($vfileroot->hasChild('filedir/warning.txt'));

        $this->assertEquals(

            'This directory contains the content of uploaded files and is controlled by Moodle code. ' .

                'Do not manually move, change or rename any of the files and subdirectories here.',

            $vfileroot->getChild('filedir/warning.txt')->getContent()

        );

    }

    /**

     * Ensure that the default implementation of get_remote_path_from_hash

     * simply calls get_local_path_from_hash.

     *

     * @covers ::get_remote_path_from_hash

     */

    public function test_get_remote_path_from_hash(): void {

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $expectedresult = (object) [];

        $fs = $this->get_testable_mock([

            'get_local_path_from_hash',

        ]);

        $fs->expects($this->once())

            ->method('get_local_path_from_hash')

            ->with($this->equalTo($contenthash), $this->equalTo(false))

            ->willReturn($expectedresult);

        $method = new \ReflectionMethod(file_system_filedir::class, 'get_remote_path_from_hash');

        $result = $method->invokeArgs($fs, [$contenthash]);

        $this->assertEquals($expectedresult, $result);

    }

    /**

     * Test the stock implementation of get_local_path_from_storedfile_with_recovery with no file found and

     * a failed recovery.

     *

     * @covers ::get_local_path_from_storedfile

     */

    public function test_get_local_path_from_storedfile_with_recovery(): void {

        $filecontent = 'example content';

        $file = $this->get_stored_file($filecontent);

        $fs = $this->get_testable_mock([

            'get_local_path_from_hash',

            'recover_file',

        ]);

        $filepath = '/path/to/nonexistent/file';

        $fs->method('get_local_path_from_hash')

            ->willReturn($filepath);

        $fs->expects($this->once())

            ->method('recover_file')

            ->with($this->equalTo($file));

        $file = $this->get_stored_file('example content');

        $result = $fs->get_local_path_from_storedfile($file, true);

        $this->assertEquals($filepath, $result);

    }

    /**

     * Test the stock implementation of get_local_path_from_storedfile_with_recovery with no file found and

     * a failed recovery.

     *

     * @covers ::get_local_path_from_storedfile

     */

    public function test_get_local_path_from_storedfile_without_recovery(): void {

        $filecontent = 'example content';

        $file = $this->get_stored_file($filecontent);

        $fs = $this->get_testable_mock([

            'get_local_path_from_hash',

            'recover_file',

        ]);

        $filepath = '/path/to/nonexistent/file';

        $fs->method('get_local_path_from_hash')

            ->willReturn($filepath);

        $fs->expects($this->never())

            ->method('recover_file');

        $file = $this->get_stored_file('example content');

        $result = $fs->get_local_path_from_storedfile($file, false);

        $this->assertEquals($filepath, $result);

    }

    /**

     * Test that the correct path is generated for the supplied content

     * hashes.

     *

     * @dataProvider contenthash_dataprovider

     * @param   string  $hash contenthash to test

     * @param   string  $hashdir Expected format of content directory

     *

     * @covers ::get_fulldir_from_hash

     */

    public function test_get_fulldir_from_hash($hash, $hashdir): void {

        global $CFG;

        $fs = new file_system_filedir();

        $method = new \ReflectionMethod(file_system_filedir::class, 'get_fulldir_from_hash');

        $result = $method->invokeArgs($fs, array($hash));

        $expectedpath = sprintf('%s/filedir/%s', $CFG->dataroot, $hashdir);

        $this->assertEquals($expectedpath, $result);

    }

    /**

     * Test that the correct path is generated for the supplied content

     * hashes when used with a stored_file.

     *

     * @dataProvider contenthash_dataprovider

     * @param   string  $hash contenthash to test

     * @param   string  $hashdir Expected format of content directory

     *

     * @covers ::get_fulldir_from_storedfile

     */

    public function test_get_fulldir_from_storedfile($hash, $hashdir): void {

        global $CFG;

        $file = $this->getMockBuilder('stored_file')

            ->disableOriginalConstructor()

            ->onlyMethods([

                'sync_external_file',

                'get_contenthash',

            ])

            ->getMock();

        $file->method('get_contenthash')->willReturn($hash);

        $fs = new file_system_filedir();

        $method = new \ReflectionMethod('file_system_filedir', 'get_fulldir_from_storedfile');

        $result = $method->invokeArgs($fs, array($file));

        $expectedpath = sprintf('%s/filedir/%s', $CFG->dataroot, $hashdir);

        $this->assertEquals($expectedpath, $result);

    }

    /**

     * Test that the correct content directory is generated for the supplied

     * content hashes.

     *

     * @dataProvider contenthash_dataprovider

     * @param   string  $hash contenthash to test

     * @param   string  $hashdir Expected format of content directory

     *

     * @covers ::get_contentdir_from_hash

     */

    public function test_get_contentdir_from_hash($hash, $hashdir): void {

        $method = new \ReflectionMethod(file_system_filedir::class, 'get_contentdir_from_hash');

        $fs = new file_system_filedir();

        $result = $method->invokeArgs($fs, array($hash));

        $this->assertEquals($hashdir, $result);

    }

    /**

     * Test that the correct content path is generated for the supplied

     * content hashes.

     *

     * @dataProvider contenthash_dataprovider

     * @param   string  $hash contenthash to test

     * @param   string  $hashdir Expected format of content directory

     *

     * @covers ::get_contentpath_from_hash

     */

    public function test_get_contentpath_from_hash($hash, $hashdir): void {

        $method = new \ReflectionMethod(file_system_filedir::class, 'get_contentpath_from_hash');

        $fs = new file_system_filedir();

        $result = $method->invokeArgs($fs, array($hash));

        $expectedpath = sprintf('%s/%s', $hashdir, $hash);

        $this->assertEquals($expectedpath, $result);

    }

    /**

     * Test that the correct trash path is generated for the supplied

     * content hashes.

     *

     * @dataProvider contenthash_dataprovider

     * @param   string  $hash contenthash to test

     * @param   string  $hashdir Expected format of content directory

     *

     * @covers ::get_trash_fullpath_from_hash

     */

    public function test_get_trash_fullpath_from_hash($hash, $hashdir): void {

        global $CFG;

        $fs = new file_system_filedir();

        $method = new \ReflectionMethod(file_system_filedir::class, 'get_trash_fullpath_from_hash');

        $result = $method->invokeArgs($fs, array($hash));

        $expectedpath = sprintf('%s/trashdir/%s/%s', $CFG->dataroot, $hashdir, $hash);

        $this->assertEquals($expectedpath, $result);

    }

    /**

     * Test that the correct trash directory is generated for the supplied

     * content hashes.

     *

     * @dataProvider contenthash_dataprovider

     * @param   string  $hash contenthash to test

     * @param   string  $hashdir Expected format of content directory

     *

     * @covers ::get_trash_fulldir_from_hash

     */

    public function test_get_trash_fulldir_from_hash($hash, $hashdir): void {

        global $CFG;

        $fs = new file_system_filedir();

        $method = new \ReflectionMethod(file_system_filedir::class, 'get_trash_fulldir_from_hash');

        $result = $method->invokeArgs($fs, array($hash));

        $expectedpath = sprintf('%s/trashdir/%s', $CFG->dataroot, $hashdir);

        $this->assertEquals($expectedpath, $result);

    }

    /**

     * Ensure that copying a file to a target from a stored_file works as anticipated.

     *

     * @covers ::copy_content_from_storedfile

     */

    public function test_copy_content_from_storedfile(): void {

        $this->resetAfterTest();

        global $CFG;

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $filedircontent = [

            $contenthash => $filecontent,

        ];

        $vfileroot = $this->setup_vfile_root($filedircontent, [], []);

        $fs = $this->getMockBuilder(file_system_filedir::class)

            ->disableOriginalConstructor()

            ->onlyMethods([

                'get_local_path_from_storedfile',

            ])

            ->getMock();

        $file = $this->getMockBuilder(\stored_file::class)

            ->disableOriginalConstructor()

            ->getMock();

        $sourcefile = \org\bovigo\vfs\vfsStream::url('root/filedir/' . $contenthash);

        $fs->method('get_local_path_from_storedfile')->willReturn($sourcefile);

        $targetfile = \org\bovigo\vfs\vfsStream::url('root/targetfile');

        $CFG->preventfilelocking = true;

        $result = $fs->copy_content_from_storedfile($file, $targetfile);

        $this->assertTrue($result);

        $this->assertEquals($filecontent, $vfileroot->getChild('targetfile')->getContent());

    }

    /**

     * Ensure that content recovery works.

     *

     * @covers ::recover_file

     */

    public function test_recover_file(): void {

        $this->resetAfterTest();

        // Setup the filedir.

        // This contains a virtual file which has a cache mismatch.

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $trashdircontent = [

            '0f' => [

                'f3' => [

                    $contenthash => $filecontent,

                ],

            ],

        ];

        $vfileroot = $this->setup_vfile_root([], $trashdircontent);

        $file = new \stored_file(get_file_storage(), (object) [

            'contenthash' => $contenthash,

            'filesize' => strlen($filecontent),

        ]);

        $fs = new file_system_filedir();

        $method = new \ReflectionMethod(file_system_filedir::class, 'recover_file');

        $result = $method->invokeArgs($fs, array($file));

        // Test the output.

        $this->assertTrue($result);

        $this->assertEquals($filecontent, $vfileroot->getChild('filedir/0f/f3/' . $contenthash)->getContent());

    }

    /**

     * Ensure that content recovery works.

     *

     * @covers ::recover_file

     */

    public function test_recover_file_already_present(): void {

        $this->resetAfterTest();

        // Setup the filedir.

        // This contains a virtual file which has a cache mismatch.

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $filedircontent = $trashdircontent = [

            '0f' => [

                'f3' => [

                    $contenthash => $filecontent,

                ],

            ],

        ];

        $vfileroot = $this->setup_vfile_root($filedircontent, $trashdircontent);

        $file = new \stored_file(get_file_storage(), (object) [

            'contenthash' => $contenthash,

            'filesize' => strlen($filecontent),

        ]);

        $fs = new file_system_filedir();

        $method = new \ReflectionMethod(file_system_filedir::class, 'recover_file');

        $result = $method->invokeArgs($fs, array($file));

        // Test the output.

        $this->assertTrue($result);

        $this->assertEquals($filecontent, $vfileroot->getChild('filedir/0f/f3/' . $contenthash)->getContent());

    }

    /**

     * Ensure that content recovery works.

     *

     * @covers ::recover_file

     */

    public function test_recover_file_size_mismatch(): void {

        $this->resetAfterTest();

        // Setup the filedir.

        // This contains a virtual file which has a cache mismatch.

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $trashdircontent = [

            '0f' => [

                'f3' => [

                    $contenthash => $filecontent,

                ],

            ],

        ];

        $vfileroot = $this->setup_vfile_root([], $trashdircontent);

        $file = new \stored_file(get_file_storage(), (object) [

            'contenthash' => $contenthash,

            'filesize' => strlen($filecontent) + 1,

        ]);

        $fs = new file_system_filedir();

        $method = new \ReflectionMethod(file_system_filedir::class, 'recover_file');

        $result = $method->invokeArgs($fs, array($file));

        // Test the output.

        $this->assertFalse($result);

        $this->assertFalse($vfileroot->hasChild('filedir/0f/f3/' . $contenthash));

    }

    /**

     * Ensure that content recovery works.

     *

     * @covers ::recover_file

     */

    public function test_recover_file_has_mismatch(): void {

        $this->resetAfterTest();

        // Setup the filedir.

        // This contains a virtual file which has a cache mismatch.

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $trashdircontent = [

            '0f' => [

                'f3' => [

                    $contenthash => $filecontent,

                ],

            ],

        ];

        $vfileroot = $this->setup_vfile_root([], $trashdircontent);

        $file = new \stored_file(get_file_storage(), (object) [

            'contenthash' => $contenthash . " different",

            'filesize' => strlen($filecontent),

        ]);

        $fs = new file_system_filedir();

        $method = new \ReflectionMethod(file_system_filedir::class, 'recover_file');

        $result = $method->invokeArgs($fs, array($file));

        // Test the output.

        $this->assertFalse($result);

        $this->assertFalse($vfileroot->hasChild('filedir/0f/f3/' . $contenthash));

    }

    /**

     * Ensure that content recovery works when the content file is in the

     * alt trash directory.

     *

     * @covers ::recover_file

     */

    public function test_recover_file_alttrash(): void {

        $this->resetAfterTest();

        // Setup the filedir.

        // This contains a virtual file which has a cache mismatch.

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $trashdircontent = [

            $contenthash => $filecontent,

        ];

        $vfileroot = $this->setup_vfile_root([], $trashdircontent);

        $file = new \stored_file(get_file_storage(), (object) [

            'contenthash' => $contenthash,

            'filesize' => strlen($filecontent),

        ]);

        $fs = new file_system_filedir();

        $method = new \ReflectionMethod(file_system_filedir::class, 'recover_file');

        $result = $method->invokeArgs($fs, array($file));

        // Test the output.

        $this->assertTrue($result);

        $this->assertEquals($filecontent, $vfileroot->getChild('filedir/0f/f3/' . $contenthash)->getContent());

    }

    /**

     * Test that an appropriate error message is generated when adding a

     * file to the pool when the pool directory structure is not writable.

     *

     * @covers ::recover_file

     */

    public function test_recover_file_contentdir_readonly(): void {

        $this->resetAfterTest();

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $filedircontent = [

            '0f' => [],

        ];

        $trashdircontent = [

            $contenthash => $filecontent,

        ];

        $vfileroot = $this->setup_vfile_root($filedircontent, $trashdircontent);

        // Make the target path readonly.

        $vfileroot->getChild('filedir/0f')

            ->chmod(0444)

            ->chown(\org\bovigo\vfs\vfsStream::OWNER_USER_2);

        $file = new \stored_file(get_file_storage(), (object) [

            'contenthash' => $contenthash,

            'filesize' => strlen($filecontent),

        ]);

        $fs = new file_system_filedir();

        $method = new \ReflectionMethod(file_system_filedir::class, 'recover_file');

        $result = $method->invokeArgs($fs, array($file));

        // Test the output.

        $this->assertFalse($result);

    }

    /**

     * Test adding a file to the pool.

     *

     * @covers ::add_file_from_path

     */

    public function test_add_file_from_path(): void {

        $this->resetAfterTest();

        global $CFG;

        // Setup the filedir.

        // This contains a virtual file which has a cache mismatch.

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $sourcedircontent = [

            'file' => $filecontent,

        ];

        $vfileroot = $this->setup_vfile_root([], [], $sourcedircontent);

        // Note, the vfs file system does not support locks - prevent file locking here.

        $CFG->preventfilelocking = true;

        // Attempt to add the file to the file pool.

        $fs = new file_system_filedir();

        $sourcefile = \org\bovigo\vfs\vfsStream::url('root/sourcedir/file');

        $result = $fs->add_file_from_path($sourcefile);

        // Test the output.

        $this->assertEquals($contenthash, $result[0]);

        $this->assertEquals(\core_text::strlen($filecontent), $result[1]);

        $this->assertTrue($result[2]);

        $this->assertEquals($filecontent, $vfileroot->getChild('filedir/0f/f3/' . $contenthash)->getContent());

    }

    /**

     * Test that an appropriate error message is generated when adding an

     * unavailable file to the pool is attempted.

     *

     * @covers ::add_file_from_path

     */

    public function test_add_file_from_path_file_unavailable(): void {

        $this->resetAfterTest();

        // Setup the filedir.

        $vfileroot = $this->setup_vfile_root();

        $this->expectException('file_exception');

        $this->expectExceptionMessageMatches(

            '/Cannot read file\. Either the file does not exist or there is a permission problem\./');

        $fs = new file_system_filedir();

        $fs->add_file_from_path(\org\bovigo\vfs\vfsStream::url('filedir/file'));

    }

    /**

     * Test that an appropriate error message is generated when specifying

     * the wrong contenthash when adding a file to the pool.

     *

     * @covers ::add_file_from_path

     */

    public function test_add_file_from_path_mismatched_hash(): void {

        $this->resetAfterTest();

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $sourcedir = [

            'file' => $filecontent,

        ];

        $vfileroot = $this->setup_vfile_root([], [], $sourcedir);

        $fs = new file_system_filedir();

        $filepath = \org\bovigo\vfs\vfsStream::url('root/sourcedir/file');

        $fs->add_file_from_path($filepath, 'eee4943847a35a4b6942c6f96daafde06bcfdfab');

        $this->assertDebuggingCalled("Invalid contenthash submitted for file $filepath");

    }

    /**

     * Test that an appropriate error message is generated when an existing

     * file in the pool has the wrong contenthash

     *

     * @covers ::add_file_from_path

     */

    public function test_add_file_from_path_existing_content_invalid(): void {

        $this->resetAfterTest();

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $filedircontent = [

            '0f' => [

                'f3' => [

                    // This contains a virtual file which has a cache mismatch.

                    '0ff30941ca5acd879fd809e8c937d9f9e6dd1615' => 'different example content',

                ],

            ],

        ];

        $sourcedir = [

            'file' => $filecontent,

        ];

        $vfileroot = $this->setup_vfile_root($filedircontent, [], $sourcedir);

        // Check that we hit the jackpot.

        $fs = new file_system_filedir();

        $filepath = \org\bovigo\vfs\vfsStream::url('root/sourcedir/file');

        $result = $fs->add_file_from_path($filepath);

        // We provided a bad hash. Check that the file was replaced.

        $this->assertDebuggingCalled("Replacing invalid content file $contenthash");

        // Test the output.

        $this->assertEquals($contenthash, $result[0]);

        $this->assertEquals(\core_text::strlen($filecontent), $result[1]);

        $this->assertFalse($result[2]);

        // Fetch the new file structure.

        $structure = \org\bovigo\vfs\vfsStream::inspect(

            new \org\bovigo\vfs\visitor\vfsStreamStructureVisitor()

        )->getStructure();

        $this->assertEquals($filecontent, $structure['root']['filedir']['0f']['f3'][$contenthash]);

    }

    /**

     * Test that an appropriate error message is generated when adding a

     * file to the pool when the pool directory structure is not writable.

     *

     * @covers ::add_file_from_path

     */

    public function test_add_file_from_path_existing_cannot_write_hashpath(): void {

        $this->resetAfterTest();

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $filedircontent = [

            '0f' => [],

        ];

        $sourcedir = [

            'file' => $filecontent,

        ];

        $vfileroot = $this->setup_vfile_root($filedircontent, [], $sourcedir);

        // Make the target path readonly.

        $vfileroot->getChild('filedir/0f')

            ->chmod(0444)

            ->chown(\org\bovigo\vfs\vfsStream::OWNER_USER_2);

        $this->expectException('file_exception');

        $this->expectExceptionMessageMatches(

            "/Cannot create local file pool directories. Please verify permissions in dataroot./");

        // Attempt to add the file to the file pool.

        $fs = new file_system_filedir();

        $sourcefile = \org\bovigo\vfs\vfsStream::url('root/sourcedir/file');

        $fs->add_file_from_path($sourcefile);

    }

    /**

     * Test adding a string to the pool.

     *

     * @covers ::add_file_from_string

     */

    public function test_add_file_from_string(): void {

        $this->resetAfterTest();

        global $CFG;

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $vfileroot = $this->setup_vfile_root();

        // Note, the vfs file system does not support locks - prevent file locking here.

        $CFG->preventfilelocking = true;

        // Attempt to add the file to the file pool.

        $fs = new file_system_filedir();

        $result = $fs->add_file_from_string($filecontent);

        // Test the output.

        $this->assertEquals($contenthash, $result[0]);

        $this->assertEquals(\core_text::strlen($filecontent), $result[1]);

        $this->assertTrue($result[2]);

    }

    /**

     * Test that an appropriate error message is generated when adding a

     * string to the pool when the pool directory structure is not writable.

     *

     * @covers ::add_file_from_string

     */

    public function test_add_file_from_string_existing_cannot_write_hashpath(): void {

        $this->resetAfterTest();

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $filedircontent = [

            '0f' => [],

        ];

        $vfileroot = $this->setup_vfile_root($filedircontent);

        // Make the target path readonly.

        $vfileroot->getChild('filedir/0f')

            ->chmod(0444)

            ->chown(\org\bovigo\vfs\vfsStream::OWNER_USER_2);

        $this->expectException('file_exception');

        $this->expectExceptionMessageMatches(

            "/Cannot create local file pool directories. Please verify permissions in dataroot./");

        // Attempt to add the file to the file pool.

        $fs = new file_system_filedir();

        $fs->add_file_from_string($filecontent);

    }

    /**

     * Test adding a string to the pool when an item with the same

     * contenthash is already present.

     *

     * @covers ::add_file_from_string

     */

    public function test_add_file_from_string_existing_matches(): void {

        $this->resetAfterTest();

        global $CFG;

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $filedircontent = [

            '0f' => [

                'f3' => [

                    $contenthash => $filecontent,

                ],

            ],

        ];

        $vfileroot = $this->setup_vfile_root($filedircontent);

        // Note, the vfs file system does not support locks - prevent file locking here.

        $CFG->preventfilelocking = true;

        // Attempt to add the file to the file pool.

        $fs = new file_system_filedir();

        $result = $fs->add_file_from_string($filecontent);

        // Test the output.

        $this->assertEquals($contenthash, $result[0]);

        $this->assertEquals(\core_text::strlen($filecontent), $result[1]);

        $this->assertFalse($result[2]);

    }

    /**

     * Test the cleanup of deleted files when there are no files to delete.

     *

     * @covers ::remove_file

     */

    public function test_remove_file_missing(): void {

        $this->resetAfterTest();

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $vfileroot = $this->setup_vfile_root();

        $fs = new file_system_filedir();

        $fs->remove_file($contenthash);

        $this->assertFalse($vfileroot->hasChild('filedir/0f/f3/' . $contenthash));

        // No file to move to trash, so the trash path will also be empty.

        $this->assertFalse($vfileroot->hasChild('trashdir/0f'));

        $this->assertFalse($vfileroot->hasChild('trashdir/0f/f3'));

        $this->assertFalse($vfileroot->hasChild('trashdir/0f/f3/' . $contenthash));

    }

    /**

     * Test the cleanup of deleted files when a file already exists in the

     * trash for that path.

     *

     * @covers ::remove_file

     */

    public function test_remove_file_existing_trash(): void {

        $this->resetAfterTest();

        $filecontent = 'example content';

        $contenthash = \file_storage::hash_from_string($filecontent);

        $filedircontent = $trashdircontent = [

            '0f' => [

                'f3' => [

                    $contenthash => $filecontent,

                ],

            ],

        ];

        $trashdircontent['0f']['f3'][$contenthash] .= 'different';

        $vfileroot = $this->setup_vfile_root($filedircontent, $trashdircontent);

        $fs = new file_system_filedir();

        $fs->remove_file($contenthash);

        $this->assertFalse($vfileroot->hasChild('filedir/0f/f3/' . $contenthash));

        $this->assertTrue($vfileroot->hasChild('trashdir/0f/f3/' . $contenthash));

        $this->assertNotEquals($filecontent, $vfileroot->getChild('trashdir/0f/f3/' . $contenthash)->getContent());

    }

    /**

     * Ensure that remove_file does nothing with an empty file.

     *

     * @covers ::remove_file

     */

    public function test_remove_file_empty(): void {

        $this->resetAfterTest();

        global $DB;

        $DB = $this->getMockBuilder(\moodle_database::class)

            ->onlyMethods(['record_exists'])

            ->getMockForAbstractClass();

        $DB->expects($this->never())

            ->method('record_exists');

        $fs = new file_system_filedir();

        $result = $fs->remove_file(\file_storage::hash_from_string(''));

        $this->assertNull($result);

    }

    /**

     * Ensure that remove_file does nothing when a file is still

     * in use.

     *

     * @covers ::remove_file

     */

    public function test_remove_file_in_use(): void {

        $this->resetAfterTest();