Platformsh\Cli\Local\LocalBuild::getTreeId PHP Method

    public function getTreeId($appRoot)
    {
        $hashes = [];
        // Get a hash representing all the files in the application, excluding
        // the project config folder (CLI_PROJECT_CONFIG_DIR).
        $tree = $this->gitHelper->execute(['ls-files', '-s'], $appRoot);
        if ($tree === false) {
            return false;
        }
        $tree = preg_replace('#^|\\n[^\\n]+?' . preg_quote($this->config->get('service.project_config_dir')) . '\\n|$#', "\n", $tree);
        $hashes[] = sha1($tree);
        // Include the hashes of untracked and modified files.
        $others = $this->gitHelper->execute(['ls-files', '--modified', '--others', '--exclude-standard', '-x ' . $this->config->get('service.project_config_dir'), '.'], $appRoot);
        if ($others === false) {
            return false;
        }
        $count = 0;
        foreach (explode("\n", $others) as $filename) {
            if ($count > 5000) {
                return false;
            }
            $filename = "{$appRoot}/{$filename}";
            if (is_file($filename)) {
                $hashes[] = sha1_file($filename);
                $count++;
            }
        }
        // Include relevant build settings.
        $relevant = ['abslinks', 'copy', 'clone', 'no-cache', 'working-copy', 'lock'];
        $settings = array_intersect_key($this->settings, array_flip($relevant));
        $hashes[] = serialize($settings);
        $hashes[] = self::BUILD_VERSION;
        // Combine them all.
        return sha1(implode(' ', $hashes));
    }

 public function testGetTreeId()
 {
     $builder = new LocalBuild();
     $treeId = $builder->getTreeId('tests/data/apps/composer');
     $this->assertEquals('944cb5782066b6bd501677a35a6399b6b7a7c573', $treeId);
 }