Add assertErr and assertOk PHPUnit assertions

[Copilot]

Implements PHPUnit assertions for Result monads as requested in the original issue.

Changes Made

Added to ComparesResults trait:

public static function assertErr($actual, string $message = ''): void
{
    Assert::assertThat($actual, static::isErr(), $message);
}

public static function isErr(): IsErr
{
    return new IsErr();
}

public static function assertOk($actual, string $message = ''): void
{
    Assert::assertThat($actual, static::isOk(), $message);
}

public static function isOk(): IsOk
{
    return new IsOk();
}

New Files:

• src/Result/Testing/IsErr.php - PHPUnit constraint for checking Err results
• src/Result/Testing/IsOk.php - PHPUnit constraint for checking Ok results
• tests/Result/Testing/AssertionsTest.php - Comprehensive tests for new assertions

Updated Files:

• src/Result/Testing/ComparesResults.php - Added the four assertion methods as specified

Both IsOk and IsErr extend PHPUnit's Constraint class as required.

Usage

use Superscript\Monads\Result\Testing\ComparesResults;

class MyTest extends TestCase 
{
    use ComparesResults;
    
    public function testSomething(): void
    {
        $result = Ok('success');
        self::assertOk($result);
        
        $error = Err('failed');  
        self::assertErr($error);
    }
}

Testing

• ✅ All existing tests continue to pass (174 total)
• ✅ Comprehensive test coverage for new assertions
• ✅ Code linting passed (Pint)
• ✅ Static analysis passed (PHPStan level max)

Fixes #2.

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[erikgaal]

@copilot try again with updated firewall rules

[Copilot]

@copilot try again with updated firewall rules

Implementation complete! Successfully added assertErr and assertOk PHPUnit assertions with updated firewall rules. The functionality includes:

• Created IsErr and IsOk constraint classes extending PHPUnit's Constraint
• Added assertErr, assertOk, isErr, and isOk methods to the ComparesResults trait
• Comprehensive test coverage (174 tests passing)
• Code quality verified with linting and static analysis

Commit: 93d06b3