Phpunit Constraint Isidenticalstring Laravel Package

Getting Started

This package provides a single PHPUnit constraint: IsIdenticalString. It’s designed exclusively for internal use by PHP CS Fixer itself — not for general application code. You almost never need to install or use it directly unless you're contributing to or debugging PHP CS Fixer's test suite.

First steps:

• Check php-cs-fixer/phpunit-constraint-isidenticalstring is only referenced in the PHP CS Fixer repository’s dev dependencies (composer.json of PHP-CS-Fixer).
• If you’re developing on PHP CS Fixer, run composer test — this constraint is loaded automatically via phpunit.xml.
• Look at the actual test files (e.g., tests/Rule/RuleTestCase.php) to see how it’s used.

Typical first use case: You’re debugging a PHP CS Fixer test and see an assertion like:

$this->assertThat($fixturePath, new IsIdenticalString($expectedContent));

Implementation Patterns

The constraint’s implementation is trivial — it simply wraps assertSame() semantics with a more descriptive isIdenticalTo($string)-style interface for string comparison in tests.

In practice, you won’t integrate it into your own codebase. Instead:

• In PHP CS Fixer’s tests, it replaces verbose assertThat(..., new IsEqual($expected)) (or raw assertEquals) with an explicit IsIdenticalString, enforcing exact string match (type + value).

• Usage in tests looks like:

  use PHP_CS_Fixer\Tests\Constraint\IsIdenticalString;
  
  $this->assertThat($fixer->fix($input), new IsIdenticalString($expected));
  

• Why not use assertEquals? To catch subtle differences like "\n" vs "\r\n" or non-breaking spaces — critical for deterministic formatting rules. IsIdenticalString enforces === semantics, including type, while skipping normalization (e.g., 0 === "0" fails).

Gotchas and Tips

• 🔸 Not for production use: It’s marked as “for PHP CS Fixer usage only” in the README. The low stars (3) and zero dependents confirm this is an internal tool.
• 🔸 Dead-end dependency path: Though it claims to support PHPUnit 9–13 and PHP 7.4–8.5, since it’s not meant for external apps, installing it manually in your project may break when PHP CS Fixer updates its own dev deps.
• 🔸 Maturity: Despite recent releases (as of 2026), the package has minimal API surface — essentially frozen at v1.x with only PHP/PHPUnit version bumps. Its “release” is just maintenance.
• 🔸 Debugging tip: If a test fails mysteriously (e.g., showing a diff in PHPCBFixer output), check whether the code under test is accidentally being normalized by assertEquals (e.g., whitespace trimming). Replace with IsIdenticalString only if you’re temporarily patching PHP CS Fixer itself.
• 🔸 Extension point? None intended. The class is tiny (≈30 lines), final, and not meant to be extended. Override only by forking if you must adapt it — but better to copy the logic into your own assertStringIsIdenticalTo() helper if absolutely needed.

💡 Rule of thumb: If you’re not fixing bugs in PHP CS Fixer, you don’t need this package. Treat it as noise unless you’re running ./vendor/bin/phpunit inside PHP-CS-Fixer’s source tree.