.php_cs

<?php

// Symfony 2.8

require __DIR__.'/vendor/autoload.php';

use PhpCsFixer\Config;
use PhpCsFixer\Finder;
use PhpCsFixer\Fixer\Import\OrderedImportsFixer;

return \PhpCsFixer\Config::create()
    ->setFinder(\PhpCsFixer\Finder::create()->in(__DIR__.'/src'))
    ->setUsingCache(false)
    ->setRiskyAllowed(true)
    ->setRules([
        'psr0' => true,
        'psr4' => true,
        'ordered_imports' => ['sortAlgorithm' => OrderedImportsFixer::SORT_LENGTH],
        'binary_operator_spaces' => ['align_equals' => true, 'align_double_arrow' => true],
    ]);

.php_cs for Symfony 4

<?php
$finder = Symfony\Component\Finder\Finder::create()
    ->in(__DIR__.'/src')
    ->name('*.php')
    ->notName('*.twig.php')
    ->ignoreDotFiles(true)
    ->ignoreVCS(true)
;

return PhpCsFixer\Config::create()
    ->setFinder($finder)
    ->setUsingCache(false)
    ->setRiskyAllowed(true)
    ->setRules(array(
        '@Symfony' => true,
        'array_syntax' => ['syntax' => 'short'],
        'binary_operator_spaces' => ['align_equals' => true, 'align_double_arrow' => true],
        'linebreak_after_opening_tag' => true,
        'not_operator_with_successor_space' => true,
        'ordered_imports' => ['sortAlgorithm' => PhpCsFixer\Fixer\Import\OrderedImportsFixer::SORT_LENGTH],
        'phpdoc_order' => true,
        'psr0' => true,
        'psr4' => true,
    ))
;