PHP 8.2 — Apply readonly classes

[s2x]

PHP 8.2 — Apply readonly classes

Problem Description

PHP 8.2 introduces the readonly class modifier, which allows marking an entire class as immutable. Classes where ALL properties are readonly can be converted to readonly class, which simplifies the code and improves its readability.

Location

Below is an analysis of classes in the project regarding the possibility of applying readonly class:

✅ Candidates for readonly class

File	Class	Justification
src/Resolver.php	Resolver	All properties are readonly
src/Reboot/Strategy/StackRebootStrategy.php	StackRebootStrategy	One readonly property
src/Scheduler/TaskErrorListener.php	TaskErrorListener	One readonly property
src/Supervisor/ProcessErrorListener.php	ProcessErrorListener	One readonly property
src/Scheduler/TaskHandler.php	TaskHandler	All properties are readonly
src/Supervisor/ProcessHandler.php	ProcessHandler	All properties are readonly
src/Middleware/StaticFilesMiddleware.php	StaticFilesMiddleware	One readonly property
src/Middleware/SymfonyController.php	SymfonyController	One readonly property
src/Event/ProcessStartEvent.php	ProcessStartEvent	All properties are readonly
src/Event/TaskStartEvent.php	TaskStartEvent	All properties are readonly
src/ServerAlreadyRunningException.php	ServerAlreadyRunningException	No own properties
src/ServerNotRunningException.php	ServerNotRunningException	No own properties
src/ServerStopFailedException.php	ServerStopFailedException	No own properties

❌ Excluded classes (have mutable properties)

File	Class	Reason for exclusion
src/KernelFactory.php	KernelFactory	Has $kernel (nullable, mutable)
src/Reboot/Strategy/ExceptionRebootStrategy.php	ExceptionRebootStrategy	Has $exception (mutable)
src/Reboot/Strategy/MaxJobsRebootStrategy.php	MaxJobsRebootStrategy	Has $jobsCount (mutable)
src/Scheduler/Trigger/CronExpressionTrigger.php	CronExpressionTrigger	Has $expression (immutable, but not readonly)
src/Event/ProcessErrorEvent.php	ProcessErrorEvent	Has $error with setter (mutable)
src/Event/TaskErrorEvent.php	TaskErrorEvent	Has $error with setter (mutable)
src/Attribute/AsTask.php	AsTask	Attributes require mutable public properties
src/Attribute/AsProcess.php	AsProcess	Attributes require mutable public properties

Analysis

Example transformation — src/Resolver.php

Before:

final class Resolver implements ResolverInterface
{
    public function __construct(private readonly ResolverInterface $resolver, private readonly array $options)
    {
    }
}

After:

final readonly class Resolver implements ResolverInterface
{
    public function __construct(private ResolverInterface $resolver, private array $options)
    {
    }
}

Example transformation — exception classes

Before:

final class ServerAlreadyRunningException extends \RuntimeException
{
    public function __construct()
    {
        parent::__construct('Workerman is already running.');
    }
}

After:

final readonly class ServerAlreadyRunningException extends \RuntimeException
{
    public function __construct()
    {
        parent::__construct('Workerman is already running.');
    }
}

Proposed Solution

For each candidate class:

1. Change class declaration from final class Foo to final readonly class Foo
2. Remove the readonly keyword from individual property declarations (they become automatically readonly at the class level)

List of changes to make:

1. src/Resolver.php — line 9
2. src/Reboot/Strategy/StackRebootStrategy.php — line 7
3. src/Scheduler/TaskErrorListener.php — line 11
4. src/Supervisor/ProcessErrorListener.php — line 11
5. src/Scheduler/TaskHandler.php — line 12
6. src/Supervisor/ProcessHandler.php — line 12
7. src/Middleware/StaticFilesMiddleware.php — line 10
8. src/Middleware/SymfonyController.php — line 13
9. src/Event/ProcessStartEvent.php — line 9
10. src/Event/TaskStartEvent.php — line 9
11. src/ServerAlreadyRunningException.php — line 7
12. src/ServerNotRunningException.php — line 7
13. src/ServerStopFailedException.php — line 7

Priority

🟡 MEDIUM — code modernization, better encapsulation. These changes improve code readability and clearly communicate class immutability, but are not critical for functionality.

Tests

After making changes:

1. Run composer install to install dependencies
2. Run vendor/bin/phpunit to ensure all tests pass
3. Run vendor/bin/rector process --dry-run to verify no additional changes
4. Check static code analysis (e.g., PHPStan)

Note: readonly class means that ALL class properties must be readonly. Before making changes, carefully verify each class to ensure it has no hidden mutable properties.

[s2x]

✅ Acceptance Requirement

Before this issue can be closed, a corresponding entry must be added to CHANGELOG.md following the Keep a Changelog format.

The changelog entry should be added under the `## [Unreleased]] section and include:

• A brief description of the change
• Reference to this issue number (e.g., (#46))
• Appropriate section: Added, Changed, Fixed, Removed, or Deprecated

[s2x]

✅ Acceptance Requirement

Before this issue can be closed, a corresponding entry must be added to CHANGELOG.md following the Keep a Changelog format.

The changelog entry should be added under the `## [Unreleased]] section and include:

• A brief description of the change
• Reference to this issue number (e.g., (#46))
• Appropriate section: Added, Changed, Fixed, Removed, or Deprecated