phpunit

phpcpd-next — PHPUnit integration

Turn copy/paste detection into a regression test. Instead of (or in addition to) running phpcpd as a separate CI step, assert that your code is duplication-free from inside your test suite — so a clone introduced in a pull request makes the build red, with the offending locations printed in the failure message.

This is a thin layer over phpcpd-next's headless mode (Phpcpd::detect()): it runs detection in-process, with no shelling out to the binary and no temp files.

What's here

File	Purpose
src/AssertNoDuplication.php	A trait adding assertNoDuplication(...) to any TestCase.
src/DuplicationConstraint.php	The underlying PHPUnit Constraint (use it directly with assertThat() if you prefer).
examples/DuplicationExampleTest.php	Copy-paste starting points.

Usage

use LucianoPereira\PhpcpdNext\PHPUnit\AssertNoDuplication;
use PHPUnit\Framework\TestCase;

final class DuplicationTest extends TestCase
{
    use AssertNoDuplication;

    public function test_app_is_dry(): void
    {
        $this->assertNoDuplication(__DIR__ . '/../app', minTokens: 70);
    }
}

Signature

$this->assertNoDuplication(
    string|array $paths = [],          // directory or list of directories to scan
    int $minTokens = 70,               // sensitivity: lower = stricter
    int $minLines  = 5,
    ?string $algorithm = null,         // null = Rabin-Karp + TokenBag; 'suffixtree' for gapped clones
    array $exclude = [],               // substring or glob patterns, e.g. '*.blade.php'
    array $suffixes = ['.php'],
    ?string $preset = null,            // a framework preset, e.g. 'laravel'
    string $message = '',
);

With a preset

// Scans app/routes/database/config and skips framework noise. No path needed.
$this->assertNoDuplication(preset: 'laravel', minTokens: 60);

Failure output

Failed asserting that the scanned code contains no duplicated code.
2 clones found:
  18 lines @ app/Services/Billing.php:42 ↔ app/Services/Invoicing.php:71
  [inconsistent] 24 lines @ app/Http/Controllers/UserController.php:90 ↔ app/Http/Controllers/AdminController.php:88

[inconsistent] marks a diverged (Type-3) clone — the dangerous kind, where one copy was patched and its sibling was not.

Installing it in your project

phpcpd-next ships these classes under the LucianoPereira\PhpcpdNext\PHPUnit\ namespace via its dev autoloader, so once phpcpd-next/phpcpd is a require-dev of your project the trait is already autoloaded — just use it.

This directory doubles as the canonical example of the integration. phpcpd-next's own tests/SelfDryTest.php uses this exact trait to guarantee its src/ stays duplication-free — the integration is dogfooded, not just documented.