Introduce abstract Message class

[vjik]

Q	A
Is bugfix?	❌
New feature?	❌
Breaks BC?	✔️
Tests pass?	✔️

Example of custom message class:

final class SmsNotification extends Message
{
    private const TYPE = 'sms';

    public function __construct(
        public readonly string $number,
        public readonly string $text,
    ) {}

    public static function fromData(string $type, mixed $data): MessageInterface
    {
        if ($type !== self::TYPE) {
            throw new InvalidArgumentException("Unsupported message type: $type");
        }

        return new self(
            number: $data['number'] ?? throw new InvalidArgumentException('Number is required.'),
            text: $data['text'] ?? throw new InvalidArgumentException('Text is required.'),
        );
    }

    public function getType(): string
    {
        return self::TYPE;
    }

    public function getData(): mixed
    {
        return [
            'number' => $this->number,
            'text' => $this->text,
        ];
    }
}

[codecov]

Codecov Report

❌ Patch coverage is 0% with 23 lines in your changes missing coverage. Please review.
✅ Project coverage is 0.00%. Comparing base (1a8ba57) to head (07e2f83).

Files with missing lines	Patch %	Lines
src/Message/GenericMessage.php	0.00%	8 Missing ⚠️
src/Message/Message.php	0.00%	6 Missing ⚠️
src/Message/Envelope.php	0.00%	5 Missing ⚠️
src/Message/JsonMessageSerializer.php	0.00%	4 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##             master    #291   +/-   ##
========================================
  Coverage      0.00%   0.00%           
- Complexity      318     320    +2     
========================================
  Files            48      49    +1     
  Lines           872     879    +7     
========================================
- Misses          872     879    +7     

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[Copilot]

Pull request overview

Refactors the Message API: Message becomes an abstract base class that only handles metadata, while the previous concrete generic implementation is extracted into a new GenericMessage class. Metadata is no longer a fromData()/constructor parameter — it is applied separately via a new withMetadata() method on MessageInterface. Envelopes can no longer be created via fromData() (they now throw LogicException and must be created from an existing message). The serializer, tests, benchmarks, and documentation are updated to use the new API and to encourage defining dedicated message subclasses.

Changes:

• MessageInterface/Message split: fromData(string, mixed) only, plus a new withMetadata(array): static; Message is abstract and owns metadata; GenericMessage replaces the old concrete generic message.
• JsonMessageSerializer defaults to GenericMessage for restoration and applies metadata via withMetadata(); Envelope::fromData() now throws and Envelope::withMetadata() re-wraps the underlying message.
• Tests/benchmarks updated from new Message(...) to new GenericMessage(...)/->withMetadata(...); README and several guides rewritten to promote per-message subclasses.

Reviewed changes

Copilot reviewed 55 out of 55 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/Message/MessageInterface.php	Drops $metadata from fromData; adds withMetadata().
src/Message/Message.php	Becomes abstract metadata base class.
src/Message/GenericMessage.php	New concrete generic message.
src/Message/JsonMessageSerializer.php	Defaults to GenericMessage, applies metadata via withMetadata.
src/Message/Envelope.php	fromData now throws; adds withMetadata that re-wraps.
tests/Unit/Support/TestMessage.php	Extends Message; retains stale $metadata param in fromData.
tests/Unit/Message/EnvelopeTest.php	Asserts Envelope::fromData() throws.
tests/Unit/Message/JsonMessageSerializerTest.php	Updated default class assertions to GenericMessage.
tests/Unit/Message/IdEnvelopeTest.php, DelayEnvelopeTest.php	Use GenericMessage + withMetadata; remove fromData tests.
tests/Unit/Middleware/.../*.php	Switch Message → GenericMessage; metadata via withMetadata.
tests/Unit/{Queue,Worker,Envelope,Stubs,Debug}*.php	Message → GenericMessage updates.
tests/Integration/MiddlewareTest.php	Message → GenericMessage; one call still passes a third [] arg.
tests/Integration/MessageConsumingTest.php, Support/TestMiddleware.php	Message → GenericMessage.
tests/Benchmark/{QueueBench,MetadataBench}.php	Updated to GenericMessage/withMetadata.
README.md, docs/guide/en/*.md	Rewritten examples to use dedicated Message subclasses.

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[samdark]

Added some ideas.