In-memory file system context for the behat PHP BDD testing framework

Question

I wanted to come up with a 'utility' context to enable testing of the file system with behat. Specifically this is aimed at helping with the behavioral testing of php command line applications that work with the file system, or use a configuration file.

I'd love for the whole repository to get a review, which has the context, a unit test suite, functional test suite, and a behat feature. It was a bit of a fiddle to get everything working well. I wanted to avoid mounting the file system scheme in the constructor so that unit tests are possible.

The main dependency this makes use of is adlawson/vfs. An alternative choice was mikey179/vfsStream.

Repository

FileSystemContext:

<?php
/**
 * This file is part of sjparkinson\behat-file-system-context.
 *
 * Copyright (c) 2015 Samuel Parkinson <[email protected]>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 * @license http://github.com/sjparkinson/behat-file-system-context/blob/master/LICENSE MIT
 */
namespace SamParkinson\Behat\Context;
use Behat\Behat\Context\Context;
use Behat\Behat\Hook\Scope\AfterScenarioScope;
use Behat\Behat\Hook\Scope\BeforeScenarioScope;
use Behat\Gherkin\Node\PyStringNode;
use Behat\Gherkin\Node\TableNode;
use Vfs\FileSystem;
use Vfs\FileSystemBuilder;
use Vfs\Node\Directory;
use Vfs\Node\File;
/**
 * Defines filesystem steps.
 *
 * @author Samuel Parkinson <[email protected]>
 */
class FileSystemContext implements Context
{
 /**
 * @var \Vfs\FileSystem
 */
 protected $fileSystem;
 /**
 * @var string
 */
 protected $scheme;
 /**
 * Creates a new instance of FileSystemContext.
 *
 * @param string $scheme
 */
 public function __construct($scheme = 'vfs://')
 {
 $this->scheme = $scheme;
 $this->fileSystem = (new FileSystemBuilder(rtrim($this->scheme, ':/\\')))->build();
 }
 /**
 * @return \Vfs\FileSystem
 */
 public function getFileSystem()
 {
 return $this->fileSystem;
 }
 /**
 * @BeforeScenario
 *
 * @param BeforeScenarioScope $scope
 */
 public function beforeScenario(BeforeScenarioScope $scope)
 {
 $this->fileSystem->mount();
 }
 /**
 * @AfterScenario
 *
 * @param AfterScenarioScope $scope
 */
 public function afterScenario(AfterScenarioScope $scope)
 {
 $this->fileSystem->unmount();
 }
 /**
 * Transform standard filenames into a virtual file system path.
 *
 * @Transform :filename
 *
 * @param string $filename
 *
 * @return string
 */
 public function transformFilenames($filename)
 {
 return $this->scheme . $filename;
 }
 /**
 * @Given :filename contains:
 * @Given the file :filename contains:
 *
 * @param string $filename
 * @param PyStringNode $contents
 */
 public function setFileContents($filename, PyStringNode $contents)
 {
 $path = dirname(substr($filename, strlen($this->scheme)));
 if (! is_dir($this->scheme . $path)) {
 mkdir($this->scheme . $path, 0777, true);
 }
 file_put_contents($filename, (string) $contents);
 }
 /**
 * @Then :filename should exist
 * @Then the file :filename should exist
 *
 * @param string $filename
 */
 public function assertFileExists($filename)
 {
 assertThat(sprintf('The file %s does not exist.', $filename), file_exists($filename));
 }
 /**
 * @Then :filename should contain:
 * @Then the file :filename should contain:
 *
 * @param string $filename
 * @param PyStringNode $contents
 */
 public function assertFileContents($filename, PyStringNode $contents)
 {
 $this->assertFileExists($filename);
 assertThat(
 sprintf('The contents of %s is not what was expected.', $filename),
 file_get_contents($filename) === (string) $contents
 );
 }
 /**
 * @Then :filename should start with:
 * @Then the file :filename should start with:
 *
 * @param string $filename
 * @param PyStringNode $contents
 */
 public function assertFileStartWith($filename, PyStringNode $contents)
 {
 $this->assertFileExists($filename);
 assertThat(
 sprintf('The contents of %s does not begin with what was expected.', $filename),
 file_get_contents($filename),
 startsWith((string) $contents)
 );
 }
 /**
 * @Then :filename should end with:
 * @Then the file :filename should end with:
 *
 * @param string $filename
 * @param PyStringNode $contents
 */
 public function assertFileEndsWith($filename, PyStringNode $contents)
 {
 $this->assertFileExists($filename);
 assertThat(
 sprintf('The contents of %s does not end with what was expected.', $filename),
 file_get_contents($filename),
 endsWith((string) $contents)
 );
 }
 /**
 * @Then print the contents of :filename
 * @Then print the contents of file :filename
 *
 * @param string $filename
 */
 public function printFileContents($filename)
 {
 $this->assertFileExists($filename);
 echo(file_get_contents($filename));
 }
}

• Sᴀᴍ Onᴇᴌᴀ: While the description states "I'd love for the whole repository to get a review...", see the help center page How do I ask a good question?, which includes this segment: "Be sure to embed the code you want reviewed in the question itself; "