diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7d94f8a..32b89a8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       matrix:
         operating-system: ['ubuntu-latest']
-        php-versions: ['7.2', '7.3', '7.4', '8.0']
+        php-versions: ['8.1']
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -21,5 +21,8 @@ jobs:
       - name: Install dependencies
         run: composer install
 
+      - name: Install fixtures
+        run: composer install-fixtures
+
       - name: Run unit tests
         run: ./vendor/bin/phpunit
diff --git a/.gitignore b/.gitignore
index 8f7045c..4ece3d5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,7 @@
 /composer.lock
 /vendor/
 /.phpunit.result.cache
+/tests/fixtures/custom-vendor/foo
+/tests/fixtures/default/web
+/tests/fixtures/default/vendor
+/tests/fixtures/*/composer.lock
diff --git a/README.md b/README.md
index c68c09a..768140d 100644
--- a/README.md
+++ b/README.md
@@ -3,45 +3,22 @@
 [![GitHub Workflow Status](https://img.shields.io/github/workflow/status/webflo/drupal-finder/CI)](https://github.com/webflo/drupal-finder/actions/workflows/ci.yml)
 [![Packagist](https://img.shields.io/packagist/v/webflo/drupal-finder.svg)](https://packagist.org/packages/webflo/drupal-finder)
 
-Drupal Finder provides a class to locate a Drupal installation in a given path.
+Drupal Finder provides a class to locate a Drupal installation based on Composer metadata.
 
 ## Usage
 
 ```PHP
-$drupalFinder = new \DrupalFinder\DrupalFinder(getcwd());
+$drupalFinder = new \DrupalFinder\DrupalFinder();
 
 $drupalRoot = $drupalFinder->getDrupalRoot();
 $composerRoot = $drupalFinder->getComposerRoot();
 $vendorDir = $drupalFinder->getVendorDir();
 ```
 
-### Environment variables
-
-If a set of environment variables is specified, then Drupal Finder uses those
-values to determine the paths of the pertinent directories:
-
-- `DRUPAL_FINDER_DRUPAL_ROOT`
-- `DRUPAL_FINDER_COMPOSER_ROOT`
-- `DRUPAL_FINDER_VENDOR_DIR`
-
-For example:
-
-- `DRUPAL_FINDER_DRUPAL_ROOT=/var/www/web`
-- `DRUPAL_FINDER_COMPOSER_ROOT=/var/www`
-- `DRUPAL_FINDER_VENDOR_DIR=/var/www/vendor`
-
-This is useful for situations where you are containerizing an application,
-directories may be in odd places, or a composer.json might be missing since it
-is unneeded in a final build artifact.
-
-You are not required to set all the environment variables to use this
-feature. If you set an environment variable, then its associated getter
-function will return the value assigned to the environment variable.
-
 ## Examples
 
 - [Drupal Console Launcher](https://github.com/hechoendrupal/drupal-console-launcher)
-- [Drush Launcher](https://github.com/drush-ops/drush-launcher)
+- [Drush](https://github.com/drush-ops/drush)
 
 ## License
 
diff --git a/composer.json b/composer.json
index 703c2a8..cd72939 100644
--- a/composer.json
+++ b/composer.json
@@ -1,6 +1,6 @@
 {
     "name": "webflo/drupal-finder",
-    "description": "Helper class to locate a Drupal installation from a given path.",
+    "description": "Helper class to locate a Drupal installation.",
     "license": "GPL-2.0-or-later",
     "type": "library",
     "authors": [
@@ -10,12 +10,13 @@
         }
     ],
     "require": {
-        "ext-json": "*"
+        "composer-runtime-api": "^2.2",
+        "php": ">=8.1"
     },
     "autoload": {
-        "classmap": [
-            "src/DrupalFinder.php"
-        ]
+        "psr-4": {
+            "DrupalFinder\\": "src/"
+        }
     },
     "autoload-dev": {
         "psr-4": {
@@ -23,7 +24,27 @@
         }
     },
     "require-dev": {
-        "phpunit/phpunit": "^8.5.14",
-        "mikey179/vfsstream": "^1.6"
+        "phpunit/phpunit": "^10.4"
+    },
+    "config": {
+        "platform": {
+            "php": "8.1"
+        }
+    },
+    "scripts": {
+        "install-fixtures": [
+            "cd tests/fixtures/custom-vendor && composer install",
+            "cd tests/fixtures/default && composer install"
+        ],
+        "uninstall-fixtures": [
+            "rm -rf tests/fixtures/*/composer.lock",
+            "rm -rf tests/fixtures/custom-vendor/foo",
+            "rm -rf tests/fixtures/default/web",
+            "rm -rf tests/fixtures/default/vendor"
+        ],
+        "reinstall-fixtures": [
+            "@uninstall-fixtures",
+            "@install-fixtures"
+        ]
     }
 }
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 92f27db..34265ab 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -3,6 +3,7 @@
   <testsuites>
     <testsuite name="DrupalFinder Test Suite">
       <directory>./tests</directory>
+      <exclude>./tests/fixtures</exclude>
     </testsuite>
   </testsuites>
 </phpunit>
diff --git a/src/DrupalFinder.php b/src/DrupalFinder.php
index ffbcecd..cbeae74 100644
--- a/src/DrupalFinder.php
+++ b/src/DrupalFinder.php
@@ -7,294 +7,35 @@
 
 namespace DrupalFinder;
 
+use Composer\InstalledVersions;
+
 class DrupalFinder
 {
     /**
-     * Drupal root environment variable.
-     */
-    const ENV_DRUPAL_ROOT = 'DRUPAL_FINDER_DRUPAL_ROOT';
-
-    /**
-     * Composer root environment variable.
-     */
-    const ENV_COMPOSER_ROOT = 'DRUPAL_FINDER_COMPOSER_ROOT';
-
-    /**
-     * Vendor directory environment variable.
-     */
-    const ENV_VENDOR_DIR = 'DRUPAL_FINDER_VENDOR_DIR';
-
-    /**
-     * Drupal web public directory.
-     *
-     * @var string
-     */
-    private $drupalRoot;
-
-    /**
-     * Drupal package composer directory.
-     *
-     * @var bool
-     */
-    private $composerRoot;
-
-    /**
-     * Composer vendor directory.
-     *
-     * @var string
-     *
-     * @see https://getcomposer.org/doc/06-config.md#vendor-dir
-     */
-    private $vendorDir;
-
-    /**
-     * Initialize finder.
-     *
-     * Optionally pass the starting path.
-     *
-     * @param string|null $start_path
-     *   The path to begin the search from.
-     *
-     * @throws \Exception
-     * @todo Make $start_path mandatory in v2.
+     * Get the Drupal root path.
      */
-    public function __construct($start_path = null) {
-        // Initialize path variables to false, indicating their locations are
-        // not yet known.
-        $this->drupalRoot = false;
-        $this->composerRoot = false;
-        $this->vendorDir = false;
-
-        // If a starting path was provided, attempt to locate and set path
-        // variables.
-        if (!empty($start_path)) {
-            $this->discoverRoots($start_path);
-        }
-    }
-
-    /**
-     * Locate Drupal, Composer, and vendor directory paths.
-     *
-     * @param string $start_path
-     *   The path to begin the search from.
-     *
-     * @return bool
-     *   True if the Drupal root was identified, false otherwise.
-     *
-     * @throws \Exception
-     *
-     * @deprecated Will be removed in v2. Future usage should instantiate
-     *   a new DrupalFinder object by passing the starting path to its
-     *   constructor.
-     */
-    public function locateRoot($start_path)
+    public function getDrupalRoot(): ?string
     {
-        $this->discoverRoots($start_path);
-        return !empty($this->getDrupalRoot());
+      $core = InstalledVersions::getInstallPath('drupal/core');
+      return $core ? realpath(dirname($core)) : null;
     }
 
     /**
-     * Get the Drupal root.
-     *
-     * @return string|bool
-     *   The path to the Drupal root, if it was discovered. False otherwise.
+     * Get the path to the Composer root directory.
      */
-    public function getDrupalRoot()
+    public function getComposerRoot(): ?string
     {
-        $environment_path = $this->getValidEnvironmentVariablePath(self::ENV_DRUPAL_ROOT);
-
-        return !empty($environment_path) ? $environment_path : $this->drupalRoot;
-    }
-
-    /**
-     * Get the Composer root.
-     *
-     * @return string|bool
-     *   The path to the Composer root, if it was discovered. False otherwise.
-     */
-    public function getComposerRoot()
-    {
-        $environment_path = $this->getValidEnvironmentVariablePath(self::ENV_COMPOSER_ROOT);
-        return !empty($environment_path) ? $environment_path : $this->composerRoot;
+        $root = InstalledVersions::getRootPackage();
+        return realpath($root['install_path']);
     }
 
     /**
      * Get the vendor path.
-     *
-     * @return string|bool
-     *   The path to the vendor directory, if it was found. False otherwise.
-     */
-    public function getVendorDir()
-    {
-        $environment_path = $this->getValidEnvironmentVariablePath(self::ENV_VENDOR_DIR);
-        return !empty($environment_path) ? $environment_path : $this->vendorDir;
-    }
-
-    /**
-     * Discover all valid paths.
-     *
-     * @param $start_path
-     *   The path to start the search from.
-     *
-     * @throws \Exception
-     */
-    protected function discoverRoots($start_path) {
-        // Since we are discovering, reset all path variables.
-        $this->drupalRoot = false;
-        $this->composerRoot = false;
-        $this->vendorDir = false;
-
-        foreach (array(true, false) as $follow_symlinks) {
-            $path = $start_path;
-            if ($follow_symlinks && is_link($path)) {
-                $path = realpath($path);
-            }
-
-            // Check the start path.
-            if ($this->findAndValidateRoots($path)) {
-                return;
-            } else {
-                // Move up dir by dir and check each.
-                while ($path = $this->shiftPathUp($path)) {
-                    if ($follow_symlinks && is_link($path)) {
-                        $path = realpath($path);
-                    }
-                    if ($this->findAndValidateRoots($path)) {
-                        return;
-                    }
-                }
-            }
-        }
-    }
-
-    /**
-     * Determine if a valid Drupal root exists.
-     *
-     * In addition, set any valid path properties if they are found.
-     *
-     * @param $path
-     *   The starting path to search from.
-     *
-     * @return bool
-     *   True if all roots were discovered and validated. False otherwise.
-     */
-    protected function findAndValidateRoots($path)
-    {
-
-        if (!empty($path) && is_dir($path) && file_exists($path . '/autoload.php') && file_exists($path . '/' . $this->getComposerFileName())) {
-            // Additional check for the presence of core/composer.json to
-            // grant it is not a Drupal 7 site with a base folder named "core".
-            $candidate = 'core/includes/common.inc';
-            if (file_exists($path . '/' . $candidate) && file_exists($path . '/core/core.services.yml')) {
-                if (file_exists($path . '/core/misc/drupal.js') || file_exists($path . '/core/assets/js/drupal.js')) {
-                    $this->composerRoot = $path;
-                    $this->drupalRoot = $path;
-                    $this->vendorDir = $this->composerRoot . '/vendor';
-                }
-            }
-        }
-        if (!empty($path) && is_dir($path) && file_exists($path . '/' . $this->getComposerFileName())) {
-            $json = json_decode(
-                file_get_contents($path . '/' . $this->getComposerFileName()),
-                true
-            );
-
-            if (is_null($json)) {
-                throw new \Exception('Unable to decode ' . $path . '/' . $this->getComposerFileName());
-            }
-
-            if (is_array($json)) {
-                if (isset($json['extra']['installer-paths']) && is_array($json['extra']['installer-paths'])) {
-                    foreach ($json['extra']['installer-paths'] as $install_path => $items) {
-                        if (in_array('type:drupal-core', $items) ||
-                            in_array('drupal/core', $items) ||
-                            in_array('drupal/drupal', $items)) {
-                            $this->composerRoot = $path;
-                            // @todo: Remove this magic and detect the major version instead.
-                            if (($install_path == 'core') || ((isset($json['name'])) && ($json['name'] == 'drupal/drupal'))) {
-                                $install_path = '';
-                            } elseif (substr($install_path, -5) == '/core') {
-                                $install_path = substr($install_path, 0, -5);
-                            }
-                            $this->drupalRoot = rtrim($path . '/' . $install_path, '/');
-                            $this->vendorDir = $this->composerRoot . '/vendor';
-                        }
-                    }
-                }
-            }
-        }
-        if ($this->composerRoot && file_exists($this->composerRoot . '/' . $this->getComposerFileName())) {
-            $json = json_decode(
-                file_get_contents($path . '/' . $this->getComposerFileName()),
-                true
-            );
-            if (is_array($json) && isset($json['config']['vendor-dir'])) {
-                $this->vendorDir = $this->composerRoot . '/' . $json['config']['vendor-dir'];
-            }
-        }
-
-        return $this->allPathsDiscovered();
-    }
-
-    /**
-     * @return string
-     */
-    protected function getComposerFileName()
-    {
-        return trim(getenv('COMPOSER')) ?: 'composer.json';
-    }
-
-    /**
-     * Helper function to quickly determine whether or not all paths were discovered.
-     *
-     * @return bool
-     *   True if all paths have been discovered, false if one or more haven't been found.
      */
-    protected function allPathsDiscovered() {
-        return !empty($this->drupalRoot) && !empty($this->composerRoot) && !empty($this->vendorDir);
-    }
-
-    /**
-     * Helper function to quickly determine whether or not all paths are known.
-     *
-     * @return bool
-     *   True if all paths are known, false if one or more paths are unknown.
-     */
-    protected function allPathsKnown() {
-        return !empty($this->getDrupalRoot()) && !empty($this->getComposerRoot()) && !empty($this->getVendorDir());
-    }
-
-    /**
-     * Get path stored in environment variable.
-     *
-     * @param string $variable
-     *   The name of the environment variable to retrieve the path from.
-     *
-     * @return false|string
-     *   A path if it is valid. False otherwise.
-     */
-    protected function getValidEnvironmentVariablePath($variable) {
-        $path = getenv($variable);
-        if (is_string($path) && is_dir($path)) {
-            return $path;
-        }
-        return false;
-    }
-
-    /**
-     * Returns parent directory.
-     *
-     * @param string
-     *   Path to start from
-     *
-     * @return string|false
-     *   Parent path of given path or false when $path is filesystem root
-     */
-    private function shiftPathUp($path)
+    public function getVendorDir(): ?string
     {
-        $parent = dirname($path);
-
-        return in_array($parent, ['.', $path]) ? false : $parent;
+      $reflection = new \ReflectionClass(InstalledVersions::class);
+      return realpath(dirname(dirname($reflection->getFileName())));
     }
 
 }
diff --git a/tests/Drupal7FinderTest.php b/tests/Drupal7FinderTest.php
deleted file mode 100644
index 9d84d61..0000000
--- a/tests/Drupal7FinderTest.php
+++ /dev/null
@@ -1,169 +0,0 @@
-<?php
-
-namespace DrupalFinder\Tests;
-
-use DrupalFinder\DrupalFinder;
-use org\bovigo\vfs\vfsStream;
-
-class Drupal7FinderTest extends DrupalFinderTestBase
-{
-    protected static $fileStructure = [
-        'includes' => [
-            'common.inc' => '',
-        ],
-        'misc' => [
-            'drupal.js' => '',
-        ],
-        'sites' => [
-            'all' => [
-                'modules' => []
-            ]
-        ]
-    ];
-
-    /**
-     * @return array
-     */
-    protected function getDrupalComposerStructure()
-    {
-        $fileStructure = [
-            'web' => static::$fileStructure,
-            'composer.json' => [
-                'require' => [
-                    'drupal/drupal' => '*',
-                ],
-                'extra' => [
-                    'installer-paths' => [
-                        'web/' => [
-                            'type:drupal-core',
-                        ],
-                    ],
-                ],
-            ],
-            'vendor' => [],
-        ];
-        return $fileStructure;
-    }
-
-    public function testDrupalComposerStructure()
-    {
-        $fileStructure = $this->getDrupalComposerStructure();
-        $this->assertComposerStructure($fileStructure);
-    }
-
-    public function testDrupalComposerStructureWithoutRequire()
-    {
-        $fileStructure = [
-            'web' => static::$fileStructure,
-            'composer.json' => [
-                'extra' => [
-                    'installer-paths' => [
-                        'web' => [
-                            'drupal/drupal',
-                        ],
-                    ],
-                ],
-            ],
-        ];
-        $this->assertComposerStructure($fileStructure);
-    }
-
-    public function testNoDrupalRootWithRealFilesystem()
-    {
-        $finder = new DrupalFinder();
-        $root = $this->tempdir(sys_get_temp_dir());
-
-        $this->assertFalse($finder->locateRoot($root));
-        $this->assertFalse($finder->getDrupalRoot());
-        $this->assertFalse($finder->getComposerRoot());
-        $this->assertFalse($finder->getVendorDir());
-    }
-
-    public function testDrupalComposerStructureWithRealFilesystem()
-    {
-        $finder = new DrupalFinder();
-        $root = $this->tempdir(sys_get_temp_dir());
-        $this->dumpToFileSystem($this->getDrupalComposerStructure(), $root);
-
-        $this->assertTrue($finder->locateRoot($root));
-        $this->assertSame($root . '/web', $finder->getDrupalRoot());
-        $this->assertSame($root, $finder->getComposerRoot());
-        $this->assertSame($root . '/vendor', $finder->getVendorDir());
-
-        // Test symlink implementation
-        $symlink = $this->tempdir(sys_get_temp_dir());
-        $this->symlink($root, $symlink . '/foo');
-
-        $this->assertTrue($finder->locateRoot($symlink . '/foo'));
-        $this->assertSame($root . '/web', $finder->getDrupalRoot());
-        $this->assertSame($root, $finder->getComposerRoot());
-        $this->assertSame($root . '/vendor', $finder->getVendorDir());
-    }
-
-    public function testDrupalWithLinkedModule()
-    {
-        $finder = new DrupalFinder();
-        $root = $this->tempdir(sys_get_temp_dir());
-        $this->dumpToFileSystem($this->getDrupalComposerStructure(), $root);
-
-        $module = $this->tempdir(sys_get_temp_dir());
-        $module_link = $root . '/web/sites/all/modules/foo';
-        $this->symlink($module, $module_link);
-
-        $this->assertTrue($finder->locateRoot($module_link));
-        $this->assertSame($root . '/web', realpath($finder->getDrupalRoot()));
-        $this->assertSame($root, realpath($finder->getComposerRoot()));
-        $this->assertSame($root . '/vendor', realpath($finder->getVendorDir()));
-    }
-
-    public function testDrupalWithCustomVendor()
-    {
-        $finder = new DrupalFinder();
-        $root = $this->tempdir(sys_get_temp_dir());
-        $fileStructure = $this->getDrupalComposerStructure();
-        $composerJson = $fileStructure['composer.json'];
-        $composerJson['config']['vendor-dir'] = 'vendor-foo';
-        $fileStructure['composer.json'] = $composerJson;
-        $fileStructure['vendor-foo'] = [];
-        $this->dumpToFileSystem($fileStructure, $root);
-
-        $this->assertTrue($finder->locateRoot($root));
-        $this->assertSame($root . '/web', realpath($finder->getDrupalRoot()));
-        $this->assertSame($root, realpath($finder->getComposerRoot()));
-        $this->assertSame($root . '/vendor-foo', realpath($finder->getVendorDir()));
-    }
-
-    /**
-     * @param $fileStructure
-     */
-    protected function assertComposerStructure($fileStructure)
-    {
-        $finder = new DrupalFinder();
-        $fileStructure = $this->prepareFileStructure($fileStructure);
-        $root = vfsStream::setup('root', null, $fileStructure);
-        $this->assertTrue($finder->locateRoot($root->url() . '/web'));
-        $this->assertSame('vfs://root/web', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $this->assertTrue($finder->locateRoot($root->url() . '/web/misc'));
-        $this->assertSame('vfs://root/web', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $this->assertTrue($finder->locateRoot($root->url()));
-        $this->assertSame('vfs://root/web', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $root = vfsStream::setup(
-            'root',
-            null,
-            ['nested_folder' => $fileStructure]
-        );
-        $this->assertFalse($finder->locateRoot($root->url()));
-        $this->assertFalse($finder->getDrupalRoot());
-        $this->assertFalse($finder->getComposerRoot());
-        $this->assertFalse($finder->getVendorDir());
-    }
-}
diff --git a/tests/Drupal8FinderTest.php b/tests/Drupal8FinderTest.php
deleted file mode 100644
index 2d00e44..0000000
--- a/tests/Drupal8FinderTest.php
+++ /dev/null
@@ -1,343 +0,0 @@
-<?php
-
-namespace DrupalFinder\Tests;
-
-use org\bovigo\vfs\vfsStream;
-use DrupalFinder\DrupalFinder;
-
-class Drupal8FinderTest extends DrupalFinderTestBase
-{
-    protected static $fileStructure = [
-        'autoload.php' => '',
-        'composer.json' => [
-            'extra' => [
-                'installer-paths' => [
-                    'core' => [
-                        'type:drupal-core'
-                    ]
-                ]
-            ]
-        ],
-        'core' => [
-            'includes' => [
-                'common.inc' => '',
-            ],
-            'misc' => [
-                'drupal.js' => '',
-            ],
-            'core.services.yml' => '',
-        ],
-        'modules' => [],
-        'vendor' => [],
-    ];
-
-    protected static $fileStructureDrupal_8_8_x = [
-        'autoload.php' => '',
-        'composer.json' => [
-            'name' => 'drupal/drupal',
-            'require' => [
-                'drupal/core' => 'self.version',
-            ],
-            'extra' => [
-                'installer-paths' => [
-                    'vendor/drupal/core' => [
-                        'type:drupal-core',
-                    ],
-                ],
-            ],
-        ],
-        'core' => [
-            'includes' => [
-                'common.inc' => '',
-            ],
-            'misc' => [
-                'drupal.js' => '',
-            ],
-            'core.services.yml' => '',
-        ],
-        'modules' => [],
-        'vendor' => [],
-    ];
-
-    /**
-     * @return array
-     */
-    protected function getDrupalComposerStructure()
-    {
-        $fileStructure = [
-            'web' => static::$fileStructure,
-            'composer.json' => [
-                'require' => [
-                    'drupal/core' => '*',
-                ],
-                'extra' => [
-                    'installer-paths' => [
-                        'web/core' => [
-                            'type:drupal-core',
-                        ],
-                    ],
-                ],
-            ],
-            'vendor' => [],
-        ];
-        unset($fileStructure['web']['composer.json']);
-        unset($fileStructure['web']['vendor']);
-
-        return $fileStructure;
-    }
-
-    public function testDrupalDefaultStructure()
-    {
-        $finder = new DrupalFinder();
-        $root = vfsStream::setup('root', null, $this->prepareFileStructure(static::$fileStructure));
-
-        $this->assertTrue($finder->locateRoot($root->url()));
-        $this->assertSame('vfs://root', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $this->assertTrue($finder->locateRoot($root->url() . '/misc'));
-        $this->assertSame('vfs://root', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $root = vfsStream::setup(
-            'root',
-            null,
-            ['project' => $this->prepareFileStructure(static::$fileStructure)]
-        );
-        $this->assertFalse(
-            $finder->locateRoot($root->url()),
-            'Not in the scope of the project'
-        );
-        $this->assertFalse($finder->getDrupalRoot());
-        $this->assertFalse($finder->getComposerRoot());
-        $this->assertFalse($finder->getVendorDir());
-    }
-
-    public function testDrupalDefaultStructure_8_8_x()
-    {
-        $finder = new DrupalFinder();
-        $root = vfsStream::setup('root', null, $this->prepareFileStructure(static::$fileStructureDrupal_8_8_x));
-
-        $this->assertTrue($finder->locateRoot($root->url()));
-        $this->assertSame('vfs://root', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $this->assertTrue($finder->locateRoot($root->url() . '/misc'));
-        $this->assertSame('vfs://root', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $root = vfsStream::setup(
-          'root',
-          null,
-          ['project' => $this->prepareFileStructure(static::$fileStructure)]
-        );
-        $this->assertFalse(
-          $finder->locateRoot($root->url()),
-          'Not in the scope of the project'
-        );
-        $this->assertFalse($finder->getDrupalRoot());
-        $this->assertFalse($finder->getComposerRoot());
-        $this->assertFalse($finder->getVendorDir());
-    }
-
-    public function testDrupalComposerStructure()
-    {
-        $fileStructure = $this->getDrupalComposerStructure();
-        $this->assertComposerStructure($fileStructure);
-    }
-
-    public function testDrupalComposerStructureWithCustomRoot()
-    {
-        $finder = new DrupalFinder();
-        $fileStructure = [
-            'src' => static::$fileStructure,
-            'composer.json' => [
-                'require' => [
-                    'drupal/core' => '*',
-                ],
-                'extra' => [
-                    'installer-paths' => [
-                        'src/core' => [
-                            'type:drupal-core',
-                        ],
-                    ],
-                ],
-            ],
-            'vendor' => [],
-        ];
-        unset($fileStructure['src']['composer.json']);
-        unset($fileStructure['src']['vendor']);
-
-        $fileStructure = $this->prepareFileStructure($fileStructure);
-        $root = vfsStream::setup('root', null, $fileStructure);
-        $this->assertTrue($finder->locateRoot($root->url() . '/src'));
-        $this->assertSame('vfs://root/src', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $this->assertTrue($finder->locateRoot($root->url() . '/src/misc'));
-        $this->assertSame('vfs://root/src', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $this->assertTrue($finder->locateRoot($root->url()));
-        $this->assertSame('vfs://root/src', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $root = vfsStream::setup(
-            'root',
-            null,
-            ['nested_folder' => $fileStructure]
-        );
-        $this->assertFalse($finder->locateRoot($root->url()));
-        $this->assertFalse($finder->getDrupalRoot());
-        $this->assertFalse($finder->getComposerRoot());
-        $this->assertFalse($finder->getVendorDir());
-    }
-
-    public function testDrupalComposerStructureWithoutRequire()
-    {
-        $fileStructure = [
-            'web' => static::$fileStructure,
-            'composer.json' => [
-                'extra' => [
-                    'installer-paths' => [
-                        'web/core' => [
-                            'drupal/core',
-                        ],
-                    ],
-                ],
-            ],
-        ];
-        unset($fileStructure['web']['composer.json']);
-        $this->assertComposerStructure($fileStructure);
-    }
-
-    public function testNoDrupalRootWithRealFilesystem()
-    {
-        $finder = new DrupalFinder();
-        $root = $this->tempdir(sys_get_temp_dir());
-
-        $this->assertFalse($finder->locateRoot($root));
-        $this->assertFalse($finder->getDrupalRoot());
-        $this->assertFalse($finder->getComposerRoot());
-        $this->assertFalse($finder->getVendorDir());
-    }
-
-    public function testDrupalDefaultStructureWithRealFilesystem()
-    {
-        $finder = new DrupalFinder();
-        $root = $this->tempdir(sys_get_temp_dir());
-        $this->dumpToFileSystem(static::$fileStructure, $root);
-
-        $this->assertTrue($finder->locateRoot($root));
-        $this->assertSame($root, $finder->getDrupalRoot());
-        $this->assertSame($root, $finder->getComposerRoot());
-        $this->assertSame($root . '/vendor', $finder->getVendorDir());
-
-        // Test symlink implementation
-        $symlink = $this->tempdir(sys_get_temp_dir());
-        $this->symlink($root, $symlink . '/foo');
-
-        $this->assertTrue($finder->locateRoot($symlink . '/foo'));
-        $this->assertSame($root, $finder->getDrupalRoot());
-        $this->assertSame($root, $finder->getComposerRoot());
-        $this->assertSame($root . '/vendor', $finder->getVendorDir());
-    }
-
-    public function testDrupalComposerStructureWithRealFilesystem()
-    {
-        $finder = new DrupalFinder();
-        $root = $this->tempdir(sys_get_temp_dir());
-        $this->dumpToFileSystem($this->getDrupalComposerStructure(), $root);
-
-        $this->assertTrue($finder->locateRoot($root));
-        $this->assertSame($root . '/web', $finder->getDrupalRoot());
-        $this->assertSame($root, $finder->getComposerRoot());
-        $this->assertSame($root . '/vendor', $finder->getVendorDir());
-
-        // Test symlink implementation
-        $symlink = $this->tempdir(sys_get_temp_dir());
-        $this->symlink($root, $symlink . '/foo');
-
-        $this->assertTrue($finder->locateRoot($symlink . '/foo'));
-        $this->assertSame($root . '/web', $finder->getDrupalRoot());
-        $this->assertSame($root, $finder->getComposerRoot());
-        $this->assertSame($root . '/vendor', $finder->getVendorDir());
-    }
-
-    public function testDrupalWithLinkedModule()
-    {
-        $finder = new DrupalFinder();
-        $root = $this->tempdir(sys_get_temp_dir());
-        $this->dumpToFileSystem(static::$fileStructure, $root);
-
-        $module = $this->tempdir(sys_get_temp_dir());
-        $module_link = $root . '/modules/foo';
-        $this->symlink($module, $module_link);
-
-        $this->assertTrue($finder->locateRoot($module_link));
-        $this->assertSame($root, realpath($finder->getDrupalRoot()));
-        $this->assertSame($root, realpath($finder->getComposerRoot()));
-        $this->assertSame($root . '/vendor', realpath($finder->getVendorDir()));
-    }
-
-    public function testDrupalWithCustomVendor()
-    {
-        $finder = new DrupalFinder();
-        $root = $this->tempdir(sys_get_temp_dir());
-        $fileStructure = static::$fileStructure;
-        $fileStructure['composer.json'] = [
-            'config' => [
-                'vendor-dir' => 'vendor-foo'
-            ]
-        ];
-        $fileStructure['vendor-foo'] = [];
-        $this->dumpToFileSystem($fileStructure, $root);
-
-        $this->assertTrue($finder->locateRoot($root));
-        $this->assertSame($root, realpath($finder->getDrupalRoot()));
-        $this->assertSame($root, realpath($finder->getComposerRoot()));
-        $this->assertSame($root . '/vendor-foo', realpath($finder->getVendorDir()));
-    }
-
-    /**
-     * @param $fileStructure
-     */
-    protected function assertComposerStructure($fileStructure)
-    {
-        $finder = new DrupalFinder();
-        $fileStructure = $this->prepareFileStructure($fileStructure);
-        $root = vfsStream::setup('root', null, $fileStructure);
-        $this->assertTrue($finder->locateRoot($root->url() . '/web'));
-        $this->assertSame('vfs://root/web', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $this->assertTrue($finder->locateRoot($root->url() . '/web/misc'));
-        $this->assertSame('vfs://root/web', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $this->assertTrue($finder->locateRoot($root->url()));
-        $this->assertSame('vfs://root/web', $finder->getDrupalRoot());
-        $this->assertSame('vfs://root', $finder->getComposerRoot());
-        $this->assertSame('vfs://root/vendor', $finder->getVendorDir());
-
-        $root = vfsStream::setup(
-            'root',
-            null,
-            ['nested_folder' => $fileStructure]
-        );
-        $this->assertFalse($finder->locateRoot($root->url()));
-        $this->assertFalse($finder->getDrupalRoot());
-        $this->assertFalse($finder->getComposerRoot());
-        $this->assertFalse($finder->getVendorDir());
-    }
-
-}
diff --git a/tests/DrupalFinderTest.php b/tests/DrupalFinderTest.php
new file mode 100644
index 0000000..c525a90
--- /dev/null
+++ b/tests/DrupalFinderTest.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace DrupalFinder\Tests;
+
+use PHPUnit\Framework\TestCase;
+
+class DrupalFinderTest extends TestCase {
+
+  protected const installFixtures = 'Execute "composer install-fixtures" first.';
+
+  /**
+   * @runInSeparateProcess
+   */
+  public function testDefault() {
+    $basePath = realpath( __DIR__ . '/fixtures/default');
+    $this->assertDirectoryExists($basePath . '/vendor', static::installFixtures);
+    $this->assertDirectoryExists($basePath . '/web', static::installFixtures);
+
+    $result = json_decode(require $basePath  . '/drupal-finder.php', TRUE);
+    $this->assertSame($result['getComposerRoot'], $basePath);
+    $this->assertSame($result['getVendorDir'], $basePath . '/vendor');
+    $this->assertSame($result['getDrupalRoot'], $basePath . '/web');
+  }
+
+  /**
+   * @runInSeparateProcess
+   */
+  public function testCustomVendor() {
+    $basePath = realpath( __DIR__ . '/fixtures/custom-vendor');
+    $this->assertDirectoryExists($basePath . '/foo/bar', static::installFixtures);
+    $this->assertDirectoryExists($basePath . '/foo/bar/drupal', static::installFixtures);
+
+    $result = json_decode(require $basePath  . '/drupal-finder.php', TRUE);
+    $this->assertSame($result['getComposerRoot'], $basePath);
+    $this->assertSame($result['getVendorDir'], $basePath . '/foo/bar');
+    $this->assertSame($result['getDrupalRoot'], $basePath . '/foo/bar/drupal');
+  }
+
+}
diff --git a/tests/DrupalFinderTestBase.php b/tests/DrupalFinderTestBase.php
deleted file mode 100644
index d8c99a3..0000000
--- a/tests/DrupalFinderTestBase.php
+++ /dev/null
@@ -1,184 +0,0 @@
-<?php
-
-namespace DrupalFinder\Tests;
-
-use DrupalFinder\DrupalFinder;
-use Exception;
-use PHPUnit\Framework\SkippedTestError;
-use PHPUnit\Framework\TestCase;
-
-abstract class DrupalFinderTestBase extends TestCase
-{
-    /**
-     * @var string
-     */
-    protected $envNameDrupal;
-
-    /**
-     * @var string
-     */
-    protected $envNameComposer;
-
-    /**
-     * @var string
-     */
-    protected $envNameVendor;
-
-    protected function setUp(): void
-    {
-        parent::setUp();
-        $this->envNameDrupal = DrupalFinder::ENV_DRUPAL_ROOT;
-        $this->envNameComposer = DrupalFinder::ENV_COMPOSER_ROOT;
-        $this->envNameVendor = DrupalFinder::ENV_VENDOR_DIR;
-    }
-
-    protected function tearDown(): void
-    {
-        parent::tearDown();
-        // Unset variables to ensure their values don't carry over into other
-        // tests that are going to run.
-        putenv('DRUPAL_FINDER_DRUPAL_ROOT');
-        putenv('DRUPAL_FINDER_COMPOSER_ROOT');
-        putenv('DRUPAL_FINDER_VENDOR_DIR');
-    }
-
-    public function testOnlyDrupalEnvironmentVariable() {
-        $finder = new DrupalFinder();
-        $fileStructure = [
-            'web' => [],
-        ];
-
-        $root = $this->tempdir(sys_get_temp_dir());
-        $this->dumpToFileSystem($fileStructure, $root);
-
-        $drupal_root = $root . '/web';
-
-        putenv("{$this->envNameDrupal}=$drupal_root");
-
-        // DrupalFinder::locateRoot should be true if the Drupal root is known.
-        $this->assertTrue($finder->locateRoot($root));
-        $this->assertSame($finder->getDrupalRoot(), $drupal_root);
-    }
-
-    public function testOnlyVendorEnvironmentVariable() {
-        $finder = new DrupalFinder();
-        $fileStructure = [
-            'vendor' => [],
-        ];
-
-        $root = $this->tempdir(sys_get_temp_dir());
-        $this->dumpToFileSystem($fileStructure, $root);
-
-        $vendor_dir = $root . '/vendor';
-
-        putenv("{$this->envNameVendor}=$vendor_dir");
-
-        // DrupalFinder::locateRoot should be false since Drupal root is unknown.
-        $this->assertFalse($finder->locateRoot($root));
-        $this->assertSame($finder->getVendorDir(), $vendor_dir);
-    }
-
-    public function testOnlyComposerEnvironmentVariable() {
-        $finder = new DrupalFinder();
-        $fileStructure = [];
-
-        $root = $this->tempdir(sys_get_temp_dir());
-        $this->dumpToFileSystem($fileStructure, $root);
-
-        $composer_dir = $root;
-
-        putenv("{$this->envNameComposer}=$composer_dir");
-
-        // DrupalFinder::locateRoot should be false since Drupal root is unknown.
-        $this->assertFalse($finder->locateRoot($root));
-        $this->assertSame($finder->getComposerRoot(), $composer_dir);
-    }
-
-    protected function dumpToFileSystem($fileStructure, $root)
-    {
-        $fileStructure = $this->prepareFileStructure($fileStructure);
-        foreach ($fileStructure as $name => $content) {
-            if (is_array($content)) {
-                mkdir($root . '/' . $name);
-                $this->dumpToFileSystem($content, $root . '/' . $name);
-            } else {
-                file_put_contents($root . '/' . $name, $content);
-            }
-        }
-    }
-
-    protected function prepareFileStructure($fileStructure)
-    {
-        foreach ($fileStructure as $name => $content) {
-            if (($name === 'composer.json' || $name === 'composer.lock') && is_array($content)) {
-                $fileStructure[$name] = json_encode($content, JSON_UNESCAPED_SLASHES);
-            } elseif (is_array($content)) {
-                $fileStructure[$name] = $this->prepareFileStructure($content);
-            }
-        }
-        return $fileStructure;
-    }
-
-    protected function tempdir($dir, $prefix = '', $mode = 0700)
-    {
-        if (substr($dir, -1) != '/') {
-            $dir .= '/';
-        }
-        do {
-            $path = $dir . $prefix . mt_rand(0, 9999999);
-        } while (!mkdir($path, $mode));
-        register_shutdown_function(
-            [static::class, 'tempdir_remove'],
-            $path
-        );
-
-        return realpath($path);
-    }
-
-    public static function tempdir_remove($path)
-    {
-        if (is_link($path)) {
-            if (defined('PHP_WINDOWS_VERSION_BUILD')) {
-                rmdir($path);
-            } else {
-                unlink($path);
-            }
-
-            return;
-        }
-
-        foreach (scandir($path) as $child) {
-            if (in_array($child, ['.', '..'])) {
-                continue;
-            }
-            $child = "$path/$child";
-            is_dir($child) ? static::tempdir_remove($child) : unlink($child);
-        }
-        rmdir($path);
-    }
-
-    /**
-     * @param $target
-     * @param $link
-     *
-     * @throws SkippedTestError
-     */
-    protected function symlink($target, $link)
-    {
-        try {
-            return symlink($target, $link);
-        } catch (Exception $e) {
-            if (defined('PHP_WINDOWS_VERSION_BUILD')
-                && strstr($e->getMessage(), WIN_ERROR_PRIVILEGE_NOT_HELD)
-            ) {
-                $this->markTestSkipped(<<<'MESSAGE'
-No privilege to create symlinks. Run test as Administrator (elevated process).
-MESSAGE
-                );
-            }
-            throw $e;
-        }
-    }
-}
-
-define('WIN_ERROR_PRIVILEGE_NOT_HELD', '1314');
diff --git a/tests/fixtures/custom-vendor/composer.json b/tests/fixtures/custom-vendor/composer.json
new file mode 100644
index 0000000..0d1a7f3
--- /dev/null
+++ b/tests/fixtures/custom-vendor/composer.json
@@ -0,0 +1,17 @@
+{
+  "repositories": {
+    "drupal-finder": {
+      "type": "path",
+      "url": "../../../"
+    }
+  },
+  "require": {
+    "webflo/drupal-finder": "*",
+    "drupal/core": "^10"
+  },
+  "config": {
+    "vendor-dir": "foo/bar"
+  },
+  "minimum-stability": "dev",
+  "prefer-stable": true
+}
diff --git a/tests/fixtures/custom-vendor/drupal-finder.php b/tests/fixtures/custom-vendor/drupal-finder.php
new file mode 100644
index 0000000..89e6dd5
--- /dev/null
+++ b/tests/fixtures/custom-vendor/drupal-finder.php
@@ -0,0 +1,14 @@
+<?php
+
+use DrupalFinder\DrupalFinder;
+
+require __DIR__ . '/foo/bar/autoload.php';
+
+$finder = new DrupalFinder();
+
+return json_encode([
+    'getComposerRoot' => $finder->getComposerRoot(),
+    'getVendorDir' => $finder->getVendorDir(),
+    'getDrupalRoot' => $finder->getDrupalRoot(),
+  ]
+);
diff --git a/tests/fixtures/default/composer.json b/tests/fixtures/default/composer.json
new file mode 100644
index 0000000..7741bd3
--- /dev/null
+++ b/tests/fixtures/default/composer.json
@@ -0,0 +1,27 @@
+{
+  "repositories": {
+    "drupal-finder": {
+      "type": "path",
+      "url": "../../../"
+    }
+  },
+  "require": {
+    "composer/installers": "^2.2",
+    "drupal/core": "^10",
+    "webflo/drupal-finder": "*"
+  },
+  "config": {
+    "allow-plugins": {
+      "composer/installers": true
+    }
+  },
+  "extra": {
+    "installer-paths": {
+      "web/core": [
+        "type:drupal-core"
+      ]
+    }
+  },
+  "minimum-stability": "dev",
+  "prefer-stable": true
+}
diff --git a/tests/fixtures/default/drupal-finder.php b/tests/fixtures/default/drupal-finder.php
new file mode 100644
index 0000000..2669234
--- /dev/null
+++ b/tests/fixtures/default/drupal-finder.php
@@ -0,0 +1,14 @@
+<?php
+
+use DrupalFinder\DrupalFinder;
+
+require __DIR__ . '/vendor/autoload.php';
+
+$finder = new DrupalFinder();
+
+return json_encode([
+    'getComposerRoot' => $finder->getComposerRoot(),
+    'getVendorDir' => $finder->getVendorDir(),
+    'getDrupalRoot' => $finder->getDrupalRoot(),
+  ]
+);