command / query types

phpgears · Oct 5, 2019 · a35a468 · a35a468
1 parent 53b3d35
commit a35a468
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diff --git a/README.md b/README.md
@@ -60,7 +60,7 @@ class CreateUserCommand extends AbstractCommand
 In case of a command without any payload you could extend `Gears\CQRS\AbstractEmptyCommand`
 
 ```php
-use Gears\CQRS\AbstractCommand;
+use Gears\CQRS\AbstractEmptyCommand;
 
 class CreateUserCommand extends AbstractEmptyCommand
 {
@@ -96,6 +96,19 @@ class FindUserQuery extends AbstractQuery
 }
 ```
 
+In case of a query without any payload you could extend `Gears\CQRS\AbstractEmptyQuery`
+
+```php
+use Gears\CQRS\AbstractEmptyQuery;
+
+class FindAllUsersQuery extends AbstractEmptyQuery
+{
+    public static function instance(): self {
+        return new self();
+    }
+}
+```
+
 ### Handlers
 
 Commands and Queries are handed over to `Gears\CQRS\CommandHandler` and `Gears\CQRS\QueryHandler` respectively on their corresponding buses
@@ -120,7 +133,24 @@ class CreateUserCommandHandler extends AbstractCommandHandler
             $command->getBirthDate()
         );
 
-        [...]
+        // ...
+    }
+}
+
+class FindUserQueryHandler extends AbstractQueryHandler
+{
+    protected function getSupportedQueryType(): string
+    {
+        return FindUserQuery::class;
+    }
+
+    protected function handleCommand(Query $query): DTO
+    {
+        /* @var FindUserQuery $query */
+
+        // Retrieve user from persistence by it's name $query->getName()
+
+        return new UserDTO(/* parameters */);
     }
 }
 ```

diff --git a/src/AbstractCommand.php b/src/AbstractCommand.php
@@ -37,12 +37,22 @@ final protected function __construct(array $parameters)
         $this->setPayload($parameters);
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getCommandType(): string
+    {
+        return \get_called_class();
+    }
+
     /**
      * {@inheritdoc}
      */
     final public static function reconstitute(array $parameters)
     {
-        return new static($parameters);
+        $commandClass = \get_called_class();
+
+        return new $commandClass($parameters);
     }
 
     /**

diff --git a/src/AbstractCommandHandler.php b/src/AbstractCommandHandler.php
@@ -25,12 +25,12 @@ abstract class AbstractCommandHandler implements CommandHandler
      */
     final public function handle(Command $command): void
     {
-        $supportedCommandType = $this->getSupportedCommandType();
-        if (!\is_a($command, $supportedCommandType)) {
+        if ($command->getCommandType() !== $this->getSupportedCommandType()) {
             throw new InvalidCommandException(\sprintf(
-                'Command must be a "%s", "%s" given',
-                $supportedCommandType,
-                \get_class($command)
+                'Command handler "%s" can only handle "%s" commands, "%s" given',
+                self::class,
+                $this->getSupportedCommandType(),
+                $command->getCommandType()
             ));
         }
 

diff --git a/src/AbstractEmptyCommand.php b/src/AbstractEmptyCommand.php
@@ -17,7 +17,7 @@
 use Gears\Immutability\ImmutabilityBehaviour;
 
 /**
- * Abstract empty immutable event.
+ * Abstract empty immutable serializable command.
  */
 abstract class AbstractEmptyCommand implements Command
 {
@@ -33,14 +33,24 @@ final protected function __construct()
         $this->assertImmutable();
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getCommandType(): string
+    {
+        return \get_called_class();
+    }
+
     /**
      * {@inheritdoc}
      *
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      */
     final public static function reconstitute(array $parameters)
     {
-        return new static();
+        $commandClass = \get_called_class();
+
+        return new $commandClass();
     }
 
     /**

diff --git a/src/AbstractEmptyQuery.php b/src/AbstractEmptyQuery.php
@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * cqrs (https://github.com/phpgears/cqrs).
+ * CQRS base.
+ *
+ * @license MIT
+ * @link https://github.com/phpgears/cqrs
+ * @author Julián Gutiérrez <juliangut@gmail.com>
+ */
+
+declare(strict_types=1);
+
+namespace Gears\CQRS;
+
+use Gears\DTO\ScalarPayloadBehaviour;
+use Gears\Immutability\ImmutabilityBehaviour;
+
+/**
+ * Abstract empty immutable serializable query.
+ */
+abstract class AbstractEmptyQuery implements Query
+{
+    use ImmutabilityBehaviour, ScalarPayloadBehaviour {
+        ScalarPayloadBehaviour::__call insteadof ImmutabilityBehaviour;
+    }
+
+    /**
+     * AbstractEmptyQuery constructor.
+     */
+    final protected function __construct()
+    {
+        $this->assertImmutable();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getQueryType(): string
+    {
+        return \get_called_class();
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return string[]
+     */
+    final protected function getAllowedInterfaces(): array
+    {
+        return [Query::class];
+    }
+}
diff --git a/src/AbstractQuery.php b/src/AbstractQuery.php
@@ -37,6 +37,14 @@ final protected function __construct(array $parameters)
         $this->setPayload($parameters);
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getQueryType(): string
+    {
+        return \get_called_class();
+    }
+
     /**
      * {@inheritdoc}
      *

diff --git a/src/AbstractQueryHandler.php b/src/AbstractQueryHandler.php
@@ -25,12 +25,12 @@ abstract class AbstractQueryHandler implements QueryHandler
      */
     final public function handle(Query $query): DTO
     {
-        $supportedQueryType = $this->getSupportedQueryType();
-        if (!\is_a($query, $supportedQueryType)) {
+        if ($query->getQueryType() !== $this->getSupportedQueryType()) {
             throw new InvalidQueryException(\sprintf(
-                'Query command must be a "%s", "%s" given',
-                $supportedQueryType,
-                \get_class($query)
+                'Query handler "%s" can only handle "%s" queries, "%s" given',
+                self::class,
+                $this->getSupportedQueryType(),
+                $query->getQueryType()
             ));
         }
 

diff --git a/src/Command.php b/src/Command.php
@@ -18,6 +18,13 @@
  */
 interface Command
 {
+    /**
+     * Get command type.
+     *
+     * @return string
+     */
+    public function getCommandType(): string;
+
     /**
      * Check parameter existence.
      *

diff --git a/src/Query.php b/src/Query.php
@@ -18,6 +18,13 @@
  */
 interface Query
 {
+    /**
+     * Get query type.
+     *
+     * @return string
+     */
+    public function getQueryType(): string;
+
     /**
      * Check parameter existence.
      *

diff --git a/tests/CQRS/AbstractCommandHandlerTest.php b/tests/CQRS/AbstractCommandHandlerTest.php
@@ -27,7 +27,9 @@ class AbstractCommandHandlerTest extends TestCase
     public function testInvalidCommandType(): void
     {
         $this->expectException(InvalidCommandException::class);
-        $this->expectExceptionMessageRegExp('/^Command must be a ".+\\\AbstractCommandStub", ".+" given$/');
+        $this->expectExceptionMessageRegExp(
+            '/^Command handler ".+" can only handle ".+\\\AbstractCommandStub" commands, ".+" given$/'
+        );
 
         $handler = new AbstractCommandHandlerStub();
         $handler->handle(AbstractEmptyCommandStub::instance());

diff --git a/tests/CQRS/AbstractQueryHandlerTest.php b/tests/CQRS/AbstractQueryHandlerTest.php
@@ -13,8 +13,8 @@
 
 namespace Gears\CQRS\Tests;
 
-use Gears\CQRS\AbstractQuery;
 use Gears\CQRS\Exception\InvalidQueryException;
+use Gears\CQRS\Tests\Stub\AbstractEmptyQueryStub;
 use Gears\CQRS\Tests\Stub\AbstractQueryHandlerStub;
 use Gears\CQRS\Tests\Stub\AbstractQueryStub;
 use Gears\DTO\DTO;
@@ -25,24 +25,21 @@
  */
 class AbstractQueryHandlerTest extends TestCase
 {
-    public function testHandling(): void
-    {
-        $handler = new AbstractQueryHandlerStub();
-
-        static::assertInstanceOf(DTO::class, $handler->handle(AbstractQueryStub::instance()));
-    }
-
     public function testInvalidQueryType(): void
     {
         $this->expectException(InvalidQueryException::class);
-        $this->expectExceptionMessageRegExp('/^Query command must be a ".+\\\AbstractQueryStub", ".+" given$/');
+        $this->expectExceptionMessageRegExp(
+            '/^Query handler ".+" can only handle ".+\\\AbstractQueryStub" queries, ".+" given$/'
+        );
 
-        /** @var AbstractQuery $query */
-        $query = $this->getMockBuilder(AbstractQuery::class)
-            ->disableOriginalConstructor()
-            ->getMock();
+        $handler = new AbstractQueryHandlerStub();
+        $handler->handle(AbstractEmptyQueryStub::instance());
+    }
 
+    public function testHandling(): void
+    {
         $handler = new AbstractQueryHandlerStub();
-        $handler->handle($query);
+
+        static::assertInstanceOf(DTO::class, $handler->handle(AbstractQueryStub::instance()));
     }
 }
diff --git a/tests/CQRS/Stub/AbstractEmptyQueryStub.php b/tests/CQRS/Stub/AbstractEmptyQueryStub.php
@@ -0,0 +1,32 @@
+<?php
+
+/*
+ * cqrs (https://github.com/phpgears/cqrs).
+ * CQRS base.
+ *
+ * @license MIT
+ * @link https://github.com/phpgears/cqrs
+ * @author Julián Gutiérrez <juliangut@gmail.com>
+ */
+
+declare(strict_types=1);
+
+namespace Gears\CQRS\Tests\Stub;
+
+use Gears\CQRS\AbstractEmptyQuery;
+
+/**
+ * Abstract empty query stub class.
+ */
+class AbstractEmptyQueryStub extends AbstractEmptyQuery
+{
+    /**
+     * Instantiate command.
+     *
+     * @return self
+     */
+    public static function instance(): self
+    {
+        return new self();
+    }
+}