PHP-CS-Fixer/tests/AutoReview/ProjectCodeTest.php

<?php

declare(strict_types=1);

/*
 * This file is part of PHP CS Fixer.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *     Dariusz Rumiński <dariusz.ruminski@gmail.com>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

namespace PhpCsFixer\Tests\AutoReview;

use PhpCsFixer\AbstractProxyFixer;
use PhpCsFixer\DocBlock\Annotation;
use PhpCsFixer\DocBlock\DocBlock;
use PhpCsFixer\Fixer\AbstractPhpUnitFixer;
use PhpCsFixer\Fixer\PhpUnit\PhpUnitNamespacedFixer;
use PhpCsFixer\FixerFactory;
use PhpCsFixer\Preg;
use PhpCsFixer\Tests\Test\AbstractFixerTestCase;
use PhpCsFixer\Tests\Test\AbstractIntegrationTestCase;
use PhpCsFixer\Tests\TestCase;
use PhpCsFixer\Tokenizer\Token;
use PhpCsFixer\Tokenizer\Tokens;
use Symfony\Component\Finder\Finder;
use Symfony\Component\Finder\SplFileInfo;

/**
 * @author Dariusz Rumiński <dariusz.ruminski@gmail.com>
 *
 * @internal
 *
 * @coversNothing
 *
 * @group auto-review
 * @group covers-nothing
 */
final class ProjectCodeTest extends TestCase
{
    /**
     * @var null|list<array{class-string<TestCase>}>
     */
    private static ?array $testClassCases = null;

    /**
     * This structure contains older classes that are not yet covered by tests.
     *
     * It may only shrink, never add anything to it.
     *
     * @var string[]
     */
    private static $classesWithoutTests = [
        \PhpCsFixer\Console\Command\DocumentationCommand::class,
        \PhpCsFixer\Console\SelfUpdate\GithubClient::class,
        \PhpCsFixer\Documentation\DocumentationLocator::class,
        \PhpCsFixer\Documentation\FixerDocumentGenerator::class,
        \PhpCsFixer\Documentation\ListDocumentGenerator::class,
        \PhpCsFixer\Documentation\RstUtils::class,
        \PhpCsFixer\Documentation\RuleSetDocumentationGenerator::class,
        \PhpCsFixer\Runner\FileCachingLintingIterator::class,
    ];

    public static function tearDownAfterClass(): void
    {
        self::$testClassCases = null;
    }

    public function testThatClassesWithoutTestsVarIsProper(): void
    {
        $unknownClasses = array_filter(
            self::$classesWithoutTests,
            static fn (string $class): bool => !class_exists($class) && !trait_exists($class),
        );

        self::assertSame([], $unknownClasses);
    }

    /**
     * @dataProvider provideSrcConcreteClassCases
     */
    public function testThatSrcClassHaveTestClass(string $className): void
    {
        $testClassName = 'PhpCsFixer\\Tests'.substr($className, 10).'Test';

        if (\in_array($className, self::$classesWithoutTests, true)) {
            self::assertFalse(class_exists($testClassName), sprintf('Class "%s" already has tests, so it should be removed from "%s::$classesWithoutTests".', $className, __CLASS__));
            self::markTestIncomplete(sprintf('Class "%s" has no tests yet, please help and add it.', $className));
        }

        self::assertTrue(class_exists($testClassName), sprintf('Expected test class "%s" for "%s" not found.', $testClassName, $className));
        self::assertTrue(is_subclass_of($testClassName, TestCase::class), sprintf('Expected test class "%s" to be a subclass of "\PhpCsFixer\Tests\TestCase".', $testClassName));
    }

    /**
     * @dataProvider provideSrcClassesNotAbuseInterfacesCases
     */
    public function testThatSrcClassesNotAbuseInterfaces(string $className): void
    {
        $rc = new \ReflectionClass($className);

        $allowedMethods = array_map(
            function (\ReflectionClass $interface): array {
                return $this->getPublicMethodNames($interface);
            },
            $rc->getInterfaces()
        );

        if (\count($allowedMethods) > 0) {
            $allowedMethods = array_unique(array_merge(...array_values($allowedMethods)));
        }

        $allowedMethods[] = '__construct';
        $allowedMethods[] = '__destruct';
        $allowedMethods[] = '__wakeup';

        $exceptionMethods = [
            'configure', // due to AbstractFixer::configure
            'getConfigurationDefinition', // due to AbstractFixer::getConfigurationDefinition
            'getDefaultConfiguration', // due to AbstractFixer::getDefaultConfiguration
            'setWhitespacesConfig', // due to AbstractFixer::setWhitespacesConfig
        ];

        $definedMethods = $this->getPublicMethodNames($rc);

        $extraMethods = array_diff(
            $definedMethods,
            $allowedMethods,
            $exceptionMethods
        );

        sort($extraMethods);

        self::assertEmpty(
            $extraMethods,
            sprintf(
                "Class '%s' should not have public methods that are not part of implemented interfaces.\nViolations:\n%s",
                $className,
                implode("\n", array_map(static function (string $item): string {
                    return " * {$item}";
                }, $extraMethods))
            )
        );
    }

    /**
     * @dataProvider provideSrcClassCases
     */
    public function testThatSrcClassesNotExposeProperties(string $className): void
    {
        $rc = new \ReflectionClass($className);

        self::assertEmpty(
            $rc->getProperties(\ReflectionProperty::IS_PUBLIC),
            sprintf('Class \'%s\' should not have public properties.', $className)
        );

        if ($rc->isFinal()) {
            return;
        }

        $allowedProps = [];
        $definedProps = $rc->getProperties(\ReflectionProperty::IS_PROTECTED);

        if (false !== $rc->getParentClass()) {
            $allowedProps = $rc->getParentClass()->getProperties(\ReflectionProperty::IS_PROTECTED);
        }

        $allowedProps = array_map(static function (\ReflectionProperty $item): string {
            return $item->getName();
        }, $allowedProps);

        $definedProps = array_map(static function (\ReflectionProperty $item): string {
            return $item->getName();
        }, $definedProps);

        $exceptionPropsPerClass = [
            \PhpCsFixer\AbstractPhpdocTypesFixer::class => ['tags'],
            \PhpCsFixer\AbstractFixer::class => ['configuration', 'configurationDefinition', 'whitespacesConfig'],
            AbstractProxyFixer::class => ['proxyFixers'],
        ];

        $extraProps = array_diff(
            $definedProps,
            $allowedProps,
            $exceptionPropsPerClass[$className] ?? []
        );

        sort($extraProps);

        self::assertEmpty(
            $extraProps,
            sprintf(
                "Class '%s' should not have protected properties.\nViolations:\n%s",
                $className,
                implode("\n", array_map(static function (string $item): string {
                    return " * {$item}";
                }, $extraProps))
            )
        );
    }

    /**
     * @dataProvider provideTestClassCases
     */
    public function testThatTestClassesAreTraitOrAbstractOrFinal(string $testClassName): void
    {
        $rc = new \ReflectionClass($testClassName);

        self::assertTrue(
            $rc->isTrait() || $rc->isAbstract() || $rc->isFinal(),
            sprintf('Test class %s should be trait, abstract or final.', $testClassName)
        );
    }

    /**
     * @dataProvider provideTestClassCases
     */
    public function testThatTestClassesAreInternal(string $testClassName): void
    {
        $rc = new \ReflectionClass($testClassName);
        $doc = new DocBlock($rc->getDocComment());

        self::assertNotEmpty(
            $doc->getAnnotationsOfType('internal'),
            sprintf('Test class %s should have internal annotation.', $testClassName)
        );
    }

    /**
     * @dataProvider provideTestClassCases
     */
    public function testThatTestClassesPublicMethodsAreCorrectlyNamed(string $testClassName): void
    {
        $reflectionClass = new \ReflectionClass($testClassName);

        $publicMethods = array_filter(
            $reflectionClass->getMethods(\ReflectionMethod::IS_PUBLIC),
            static function (\ReflectionMethod $reflectionMethod) use ($reflectionClass): bool {
                return $reflectionMethod->getDeclaringClass()->getName() === $reflectionClass->getName();
            }
        );

        if ([] === $publicMethods) {
            $this->expectNotToPerformAssertions(); // no methods to test, all good!

            return;
        }

        foreach ($publicMethods as $method) {
            self::assertMatchesRegularExpression(
                '/^(test|expect|provide|setUpBeforeClass$|tearDownAfterClass$)/',
                $method->getName(),
                sprintf('Public method "%s::%s" is not properly named.', $reflectionClass->getName(), $method->getName())
            );
        }
    }

    /**
     * @dataProvider provideDataProviderMethodCases
     */
    public function testThatTestDataProvidersAreUsed(string $testClassName, \ReflectionMethod $dataProvider): void
    {
        $usedDataProviderMethodNames = [];

        foreach ($this->getUsedDataProviderMethodNames($testClassName) as $providerName) {
            $usedDataProviderMethodNames[] = $providerName;
        }

        $dataProviderName = $dataProvider->getName();

        self::assertContains(
            $dataProviderName,
            $usedDataProviderMethodNames,
            sprintf('Data provider in "%s" with name "%s" is not used.', $dataProvider->getDeclaringClass()->getName(), $dataProviderName)
        );
    }

    /**
     * @dataProvider provideDataProviderMethodCases
     */
    public function testThatTestDataProvidersReturnIterableOrArray(string $testClassName, \ReflectionMethod $dataProvider): void
    {
        $dataProviderName = $dataProvider->getName();

        $returnType = $dataProvider->getReturnType();

        self::assertInstanceOf(
            \ReflectionNamedType::class,
            $returnType,
            sprintf('Data provider in "%s" with name "%s" has no return type.', $dataProvider->getDeclaringClass()->getName(), $dataProviderName)
        );

        $returnTypeName = $returnType->getName();

        self::assertTrue(
            'array' === $returnTypeName || 'iterable' === $returnTypeName,
            sprintf('Data provider in "%s" with name "%s" has return type "%s", expected "array" or "iterable".', $dataProvider->getDeclaringClass()->getName(), $dataProviderName, $returnTypeName)
        );
    }

    /**
     * @dataProvider provideDataProviderMethodCases
     */
    public function testThatTestDataProvidersAreCorrectlyNamed(string $testClassName, \ReflectionMethod $dataProvider): void
    {
        $dataProviderName = $dataProvider->getShortName();

        self::assertMatchesRegularExpression('/^provide[A-Z]\S+Cases$/', $dataProviderName, sprintf(
            'Data provider in "%s" with name "%s" is not correctly named.',
            $testClassName,
            $dataProviderName
        ));
    }

    public static function provideDataProviderMethodCases(): iterable
    {
        foreach (self::provideTestClassCases() as $testClassName) {
            $testClassName = reset($testClassName);
            $reflectionClass = new \ReflectionClass($testClassName);

            $methods = array_filter(
                $reflectionClass->getMethods(\ReflectionMethod::IS_PUBLIC),
                static function (\ReflectionMethod $reflectionMethod) use ($reflectionClass): bool {
                    return $reflectionMethod->getDeclaringClass()->getName() === $reflectionClass->getName()
                        && str_starts_with($reflectionMethod->getName(), 'provide');
                }
            );

            foreach ($methods as $method) {
                yield [$testClassName, $method];
            }
        }
    }

    /**
     * @dataProvider provideTestClassCases
     */
    public function testThatTestClassCoversAreCorrect(string $testClassName): void
    {
        $reflectionClass = new \ReflectionClass($testClassName);

        if ($reflectionClass->isAbstract() || $reflectionClass->isInterface()) {
            $this->expectNotToPerformAssertions();

            return;
        }

        $doc = $reflectionClass->getDocComment();
        self::assertNotFalse($doc);

        if (1 === Preg::match('/@coversNothing/', $doc, $matches)) {
            return;
        }

        $covers = Preg::match('/@covers (\S*)/', $doc, $matches);
        self::assertNotFalse($covers, sprintf('Missing @covers in PHPDoc of test class "%s".', $testClassName));

        array_shift($matches);
        $class = '\\'.str_replace('PhpCsFixer\Tests\\', 'PhpCsFixer\\', substr($testClassName, 0, -4));
        $parentClass = (new \ReflectionClass($class))->getParentClass();
        $parentClassName = false === $parentClass ? null : '\\'.$parentClass->getName();

        foreach ($matches as $match) {
            self::assertTrue(
                $match === $class || $parentClassName === $match,
                sprintf('Unexpected @covers "%s" for "%s".', $match, $testClassName)
            );
        }
    }

    /**
     * @dataProvider provideClassesWherePregFunctionsAreForbiddenCases
     */
    public function testThereIsNoPregFunctionUsedDirectly(string $className): void
    {
        $rc = new \ReflectionClass($className);
        $tokens = Tokens::fromCode(file_get_contents($rc->getFileName()));
        $stringTokens = array_filter(
            $tokens->toArray(),
            static function (Token $token): bool {
                return $token->isGivenKind(T_STRING);
            }
        );

        $strings = array_map(
            static function (Token $token): string {
                return $token->getContent();
            },
            $stringTokens
        );

        $strings = array_unique($strings);
        $message = sprintf('Class %s must not use preg_*, it shall use Preg::* instead.', $className);
        self::assertNotContains('preg_filter', $strings, $message);
        self::assertNotContains('preg_grep', $strings, $message);
        self::assertNotContains('preg_match', $strings, $message);
        self::assertNotContains('preg_match_all', $strings, $message);
        self::assertNotContains('preg_replace', $strings, $message);
        self::assertNotContains('preg_replace_callback', $strings, $message);
        self::assertNotContains('preg_split', $strings, $message);
    }

    /**
     * @dataProvider provideTestClassCases
     */
    public function testExpectedInputOrder(string $testClassName): void
    {
        $reflectionClass = new \ReflectionClass($testClassName);

        $publicMethods = array_filter(
            $reflectionClass->getMethods(\ReflectionMethod::IS_PUBLIC),
            static function (\ReflectionMethod $reflectionMethod) use ($reflectionClass): bool {
                return $reflectionMethod->getDeclaringClass()->getName() === $reflectionClass->getName();
            }
        );

        if ([] === $publicMethods) {
            $this->expectNotToPerformAssertions(); // no methods to test, all good!

            return;
        }

        /** @var \ReflectionMethod $method */
        foreach ($publicMethods as $method) {
            $parameters = $method->getParameters();

            if (\count($parameters) < 2) {
                $this->addToAssertionCount(1); // not enough parameters to test, all good!

                continue;
            }

            $expected = [
                'expected' => false,
                'input' => false,
            ];

            for ($i = \count($parameters) - 1; $i >= 0; --$i) {
                $name = $parameters[$i]->getName();

                if (isset($expected[$name])) {
                    $expected[$name] = $i;
                }
            }

            $expected = array_filter($expected, static fn ($item): bool => false !== $item);

            if (\count($expected) < 2) {
                $this->addToAssertionCount(1); // not enough parameters to test, all good!

                continue;
            }

            self::assertLessThan(
                $expected['input'],
                $expected['expected'],
                sprintf('Public method "%s::%s" has parameter \'input\' before \'expected\'.', $reflectionClass->getName(), $method->getName())
            );
        }
    }

    /**
     * @dataProvider provideSrcClassCases
     * @dataProvider provideTestClassCases
     */
    public function testAllCodeContainSingleClassy(string $className): void
    {
        $headerTypes = [
            T_ABSTRACT,
            T_AS,
            T_COMMENT,
            T_DECLARE,
            T_DOC_COMMENT,
            T_FINAL,
            T_LNUMBER,
            T_NAMESPACE,
            T_NS_SEPARATOR,
            T_OPEN_TAG,
            T_STRING,
            T_USE,
            T_WHITESPACE,
        ];

        $rc = new \ReflectionClass($className);
        $file = $rc->getFileName();
        $tokens = Tokens::fromCode(file_get_contents($file));
        $classyIndex = null;

        self::assertTrue($tokens->isAnyTokenKindsFound(Token::getClassyTokenKinds()), sprintf('File "%s" should contains a classy.', $file));

        $count = \count($tokens);

        for ($index = 1; $index < $count; ++$index) {
            if ($tokens[$index]->isClassy()) {
                $classyIndex = $index;

                break;
            }

            if (\defined('T_ATTRIBUTE') && $tokens[$index]->isGivenKind(T_ATTRIBUTE)) {
                $index = $tokens->findBlockEnd(Tokens::BLOCK_TYPE_ATTRIBUTE, $index);

                continue;
            }

            if (!$tokens[$index]->isGivenKind($headerTypes) && !$tokens[$index]->equalsAny([';', '=', '(', ')'])) {
                self::fail(sprintf('File "%s" should only contains single classy, found "%s" @ %d.', $file, $tokens[$index]->toJson(), $index));
            }
        }

        self::assertNotNull($classyIndex, sprintf('File "%s" does not contain a classy.', $file));

        $nextTokenOfKind = $tokens->getNextTokenOfKind($classyIndex, ['{']);

        if (!\is_int($nextTokenOfKind)) {
            throw new \UnexpectedValueException('Classy without {} - braces.');
        }

        $classyEndIndex = $tokens->findBlockEnd(Tokens::BLOCK_TYPE_CURLY_BRACE, $nextTokenOfKind);

        self::assertNull($tokens->getNextNonWhitespace($classyEndIndex), sprintf('File "%s" should only contains a single classy.', $file));
    }

    /**
     * @dataProvider provideSrcClassCases
     */
    public function testInheritdocIsNotAbused(string $className): void
    {
        $rc = new \ReflectionClass($className);

        $allowedMethods = array_map(
            function (\ReflectionClass $interface): array {
                return $this->getPublicMethodNames($interface);
            },
            $rc->getInterfaces()
        );

        if (\count($allowedMethods) > 0) {
            $allowedMethods = array_merge(...array_values($allowedMethods));
        }

        $parentClass = $rc;
        while (false !== $parentClass = $parentClass->getParentClass()) {
            foreach ($parentClass->getMethods(\ReflectionMethod::IS_PUBLIC | \ReflectionMethod::IS_PROTECTED) as $method) {
                $allowedMethods[] = $method->getName();
            }
        }

        $allowedMethods = array_unique($allowedMethods);

        $methodsWithInheritdoc = array_filter(
            $rc->getMethods(),
            static function (\ReflectionMethod $rm): bool {
                return false !== $rm->getDocComment() && stripos($rm->getDocComment(), '@inheritdoc');
            }
        );

        $methodsWithInheritdoc = array_map(
            static function (\ReflectionMethod $rm): string {
                return $rm->getName();
            },
            $methodsWithInheritdoc
        );

        $extraMethods = array_diff($methodsWithInheritdoc, $allowedMethods);

        self::assertEmpty(
            $extraMethods,
            sprintf(
                "Class '%s' should not have methods with '@inheritdoc' in PHPDoc that are not inheriting PHPDoc.\nViolations:\n%s",
                $className,
                implode("\n", array_map(static function ($item): string {
                    return " * {$item}";
                }, $extraMethods))
            )
        );
    }

    public static function provideSrcClassCases(): array
    {
        return array_map(
            static function (string $item): array {
                return [$item];
            },
            self::getSrcClasses()
        );
    }

    public static function provideSrcClassesNotAbuseInterfacesCases(): array
    {
        return array_map(
            static function (string $item): array {
                return [$item];
            },
            array_filter(self::getSrcClasses(), static function (string $className): bool {
                $rc = new \ReflectionClass($className);

                $doc = false !== $rc->getDocComment()
                    ? new DocBlock($rc->getDocComment())
                    : null;

                if (
                    $rc->isInterface()
                    || (null !== $doc && \count($doc->getAnnotationsOfType('internal')) > 0)
                    || \in_array($className, [
                        \PhpCsFixer\Finder::class,
                        AbstractFixerTestCase::class,
                        AbstractIntegrationTestCase::class,
                        Tokens::class,
                    ], true)
                ) {
                    return false;
                }

                $interfaces = $rc->getInterfaces();
                $interfacesCount = \count($interfaces);

                if (0 === $interfacesCount) {
                    return false;
                }

                if (1 === $interfacesCount) {
                    $interface = reset($interfaces);

                    if ('Stringable' === $interface->getName()) {
                        return false;
                    }
                }

                return true;
            })
        );
    }

    public static function provideSrcConcreteClassCases(): array
    {
        return array_map(
            static fn (string $item): array => [$item],
            array_filter(
                self::getSrcClasses(),
                static function (string $className): bool {
                    $rc = new \ReflectionClass($className);

                    return !$rc->isTrait() && !$rc->isAbstract() && !$rc->isInterface();
                }
            )
        );
    }

    /**
     * @return iterable<array{class-string<TestCase>}>
     */
    public static function provideTestClassCases(): iterable
    {
        if (null === self::$testClassCases) {
            self::$testClassCases = array_map(
                static fn (string $item): array => [$item],
                self::getTestClasses(),
            );
        }

        yield from self::$testClassCases;
    }

    public static function provideClassesWherePregFunctionsAreForbiddenCases(): array
    {
        return array_map(
            static fn (string $item): array => [$item],
            array_filter(
                self::getSrcClasses(),
                static fn (string $className): bool => Preg::class !== $className,
            ),
        );
    }

    /**
     * @dataProvider providePhpUnitFixerExtendsAbstractPhpUnitFixerCases
     */
    public function testPhpUnitFixerExtendsAbstractPhpUnitFixer(string $className): void
    {
        $reflection = new \ReflectionClass($className);

        self::assertTrue($reflection->isSubclassOf(AbstractPhpUnitFixer::class));
    }

    public static function providePhpUnitFixerExtendsAbstractPhpUnitFixerCases(): iterable
    {
        $factory = new FixerFactory();
        $factory->registerBuiltInFixers();

        foreach ($factory->getFixers() as $fixer) {
            if (!str_starts_with($fixer->getName(), 'php_unit_')) {
                continue;
            }

            // this one fixes usage of PHPUnit classes
            if ($fixer instanceof PhpUnitNamespacedFixer) {
                continue;
            }

            if ($fixer instanceof AbstractProxyFixer) {
                continue;
            }

            yield [\get_class($fixer)];
        }
    }

    /**
     * @dataProvider provideSrcClassCases
     * @dataProvider provideTestClassCases
     */
    public function testConstantsAreInUpperCase(string $className): void
    {
        $rc = new \ReflectionClass($className);

        $reflectionClassConstants = $rc->getReflectionConstants();

        if (\count($reflectionClassConstants) < 1) {
            $this->expectNotToPerformAssertions();

            return;
        }

        foreach ($reflectionClassConstants as $constant) {
            $constantName = $constant->getName();
            self::assertSame(strtoupper($constantName), $constantName, $className);
        }
    }

    /**
     * @return iterable<string, string>
     */
    private function getUsedDataProviderMethodNames(string $testClassName): iterable
    {
        foreach ($this->getAnnotationsOfTestClass($testClassName, 'dataProvider') as $methodName => $dataProviderAnnotation) {
            if (1 === preg_match('/@dataProvider\s+(?P<methodName>\w+)/', $dataProviderAnnotation->getContent(), $matches)) {
                yield $methodName => $matches['methodName'];
            }
        }
    }

    /**
     * @return iterable<string, Annotation>
     */
    private function getAnnotationsOfTestClass(string $testClassName, string $annotation): iterable
    {
        $tokens = Tokens::fromCode(file_get_contents(
            str_replace('\\', \DIRECTORY_SEPARATOR, preg_replace('#^PhpCsFixer\\\Tests#', 'tests', $testClassName)).'.php'
        ));

        foreach ($tokens as $index => $token) {
            if (!$token->isGivenKind(T_DOC_COMMENT)) {
                continue;
            }

            $methodName = $tokens[$tokens->getNextTokenOfKind($index, [[T_STRING]])]->getContent();

            $docBlock = new DocBlock($token->getContent());
            $dataProviderAnnotations = $docBlock->getAnnotationsOfType($annotation);

            foreach ($dataProviderAnnotations as $dataProviderAnnotation) {
                yield $methodName => $dataProviderAnnotation;
            }
        }
    }

    /**
     * @return list<class-string>
     */
    private static function getSrcClasses(): array
    {
        static $classes;

        if (null !== $classes) {
            return $classes;
        }

        $finder = Finder::create()
            ->files()
            ->name('*.php')
            ->in(__DIR__.'/../../src')
            ->exclude([
                'Resources',
            ])
        ;

        $classes = array_map(
            static function (SplFileInfo $file): string {
                return sprintf(
                    '%s\\%s%s%s',
                    'PhpCsFixer',
                    strtr($file->getRelativePath(), \DIRECTORY_SEPARATOR, '\\'),
                    $file->getRelativePath() ? '\\' : '',
                    $file->getBasename('.'.$file->getExtension())
                );
            },
            iterator_to_array($finder, false)
        );

        sort($classes);

        return $classes;
    }

    /**
     * @return list<class-string<TestCase>>
     */
    private static function getTestClasses(): array
    {
        static $classes;

        if (null !== $classes) {
            return $classes;
        }

        $finder = Finder::create()
            ->files()
            ->name('*.php')
            ->in(__DIR__.'/..')
            ->exclude([
                'Fixtures',
            ])
        ;

        $classes = array_map(
            static function (SplFileInfo $file): string {
                return sprintf(
                    'PhpCsFixer\\Tests\\%s%s%s',
                    strtr($file->getRelativePath(), \DIRECTORY_SEPARATOR, '\\'),
                    $file->getRelativePath() ? '\\' : '',
                    $file->getBasename('.'.$file->getExtension())
                );
            },
            iterator_to_array($finder, false)
        );

        $classes = array_filter($classes, static function (string $class): bool {
            return is_subclass_of($class, TestCase::class);
        });

        sort($classes);

        return $classes;
    }

    /**
     * @param \ReflectionClass<object> $rc
     *
     * @return string[]
     */
    private function getPublicMethodNames(\ReflectionClass $rc): array
    {
        return array_map(
            static function (\ReflectionMethod $rm): string {
                return $rm->getName();
            },
            $rc->getMethods(\ReflectionMethod::IS_PUBLIC)
        );
    }
}