diff --git a/baseline.xml b/baseline.xml
index dba7c91b..ee6e9be1 100644
--- a/baseline.xml
+++ b/baseline.xml
@@ -86,6 +86,11 @@
       <code><![CDATA[$dateTimeType->convertToPHPValue($data['recorded_on'], $platform)]]></code>
     </MixedArgument>
   </file>
+  <file src="src/Store/InMemoryStore.php">
+    <MixedPropertyTypeCoercion>
+      <code><![CDATA[$this->messages]]></code>
+    </MixedPropertyTypeCoercion>
+  </file>
   <file src="src/Store/StreamDoctrineDbalStoreStream.php">
     <ArgumentTypeCoercion>
       <code><![CDATA[$data['playhead'] === null ? null : (int)$data['playhead']]]></code>
diff --git a/docs/pages/store.md b/docs/pages/store.md
index af05b927..5e67471f 100644
--- a/docs/pages/store.md
+++ b/docs/pages/store.md
@@ -9,27 +9,11 @@ Each message contains an event and the associated headers.
     
 The store is optimized to efficiently store and load events for aggregates.
 
-## Create DBAL connection
-
-The first thing we need for our store is a DBAL connection:
-
-```php
-use Doctrine\DBAL\DriverManager;
-use Doctrine\DBAL\Tools\DsnParser;
-
-$connection = DriverManager::getConnection(
-    (new DsnParser())->parse('pdo-pgsql://user:secret@localhost/app'),
-);
-```
-!!! note
-
-    You can find out more about how to create a connection 
-    [here](https://www.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html)
-    
 ## Configure Store
 
-We currently offer two stores, both based on the [doctrine dbal](https://www.doctrine-project.org/projects/dbal.html) library.
-The default store is the `DoctrineDbalStore` and the new experimental store is the `StreamDoctrineDbalStore`.
+We offer different stores to store the messages. 
+Two stores based on [doctrine dbal](https://www.doctrine-project.org/projects/dbal.html)
+and one in-memory store for testing purposes.
 
 ### DoctrineDbalStore
 
@@ -38,16 +22,25 @@ You can create a store with the `DoctrineDbalStore` class.
 The store needs a dbal connection, an event serializer and has some optional parameters like options.
 
 ```php
-use Doctrine\DBAL\Connection;
+use Doctrine\DBAL\DriverManager;
+use Doctrine\DBAL\Tools\DsnParser;
 use Patchlevel\EventSourcing\Serializer\DefaultEventSerializer;
 use Patchlevel\EventSourcing\Store\DoctrineDbalStore;
 
-/** @var Connection $connection */
+$connection = DriverManager::getConnection(
+    (new DsnParser())->parse('pdo-pgsql://user:secret@localhost/app'),
+);
+
 $store = new DoctrineDbalStore(
     $connection,
     DefaultEventSerializer::createFromPaths(['src/Event']),
 );
 ```
+!!! note
+
+    You can find out more about how to create a connection 
+    [here](https://www.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html)
+    
 Following options are available in `DoctrineDbalStore`:
 
 | Option            | Type            | Default    | Description                                  |
@@ -89,16 +82,25 @@ This store introduces two new methods `streams` and `remove`.
 The store needs a dbal connection, an event serializer and has some optional parameters like options.
 
 ```php
-use Doctrine\DBAL\Connection;
+use Doctrine\DBAL\DriverManager;
+use Doctrine\DBAL\Tools\DsnParser;
 use Patchlevel\EventSourcing\Serializer\DefaultEventSerializer;
 use Patchlevel\EventSourcing\Store\StreamDoctrineDbalStore;
 
-/** @var Connection $connection */
+$connection = DriverManager::getConnection(
+    (new DsnParser())->parse('pdo-pgsql://user:secret@localhost/app'),
+);
+
 $store = new StreamDoctrineDbalStore(
     $connection,
     DefaultEventSerializer::createFromPaths(['src/Event']),
 );
 ```
+!!! note
+
+    You can find out more about how to create a connection 
+    [here](https://www.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html)
+    
 Following options are available in `StreamDoctrineDbalStore`:
 
 | Option            | Type            | Default     | Description                                  |
@@ -122,6 +124,19 @@ The table structure of the `StreamDoctrineDbalStore` looks like this:
 | archived         | bool     | If the event is archived                         |
 | custom_headers   | json     | Custom headers for the event                     |
 
+### InMemoryStore
+
+We also offer an in-memory store for testing purposes.
+
+```php
+use Patchlevel\EventSourcing\Store\InMemoryStore;
+
+$store = new InMemoryStore();
+```
+!!! tip
+
+    You can pass messages to the constructor to initialize the store with some events.
+    
 ## Schema
 
 With the help of the `SchemaDirector`, the database structure can be created, updated and deleted.
@@ -130,7 +145,7 @@ With the help of the `SchemaDirector`, the database structure can be created, up
 
     You can also use doctrine migration to create and keep your schema in sync.
     
-### Schema Director
+### Doctrine Schema Director
 
 The `SchemaDirector` is responsible for creating, updating and deleting the database schema.
 The `DoctrineSchemaDirector` is a concrete implementation of the `SchemaDirector` for doctrine dbal.
@@ -159,18 +174,18 @@ $schemaDirector = new DoctrineSchemaDirector(
 You can create the table from scratch using the `create` method.
 
 ```php
-use Patchlevel\EventSourcing\Schema\DoctrineSchemaDirector;
+use Patchlevel\EventSourcing\Schema\SchemaDirector;
 
-/** @var DoctrineSchemaDirector $schemaDirector */
+/** @var SchemaDirector $schemaDirector */
 $schemaDirector->create();
 ```
 Or can give you back which SQL statements would be necessary for this.
 Either for a dry run, or to define your own migrations.
 
 ```php
-use Patchlevel\EventSourcing\Schema\DoctrineSchemaDirector;
+use Patchlevel\EventSourcing\Schema\DryRunSchemaDirector;
 
-/** @var DoctrineSchemaDirector $schemaDirector */
+/** @var DryRunSchemaDirector $schemaDirector */
 $sql = $schemaDirector->dryRunCreate();
 ```
 #### Update schema
@@ -179,17 +194,17 @@ The update method compares the current state in the database and how the table s
 As a result, the diff is executed to bring the table to the desired state.
 
 ```php
-use Patchlevel\EventSourcing\Schema\DoctrineSchemaDirector;
+use Patchlevel\EventSourcing\Schema\SchemaDirector;
 
-/** @var DoctrineSchemaDirector $schemaDirector */
+/** @var SchemaDirector $schemaDirector */
 $schemaDirector->update();
 ```
 Or can give you back which SQL statements would be necessary for this.
 
 ```php
-use Patchlevel\EventSourcing\Schema\DoctrineSchemaDirector;
+use Patchlevel\EventSourcing\Schema\DryRunSchemaDirector;
 
-/** @var DoctrineSchemaDirector $schemaDirector */
+/** @var DryRunSchemaDirector $schemaDirector */
 $sql = $schemaDirector->dryRunUpdate();
 ```
 #### Drop schema
@@ -197,17 +212,17 @@ $sql = $schemaDirector->dryRunUpdate();
 You can also delete the table with the `drop` method.
 
 ```php
-use Patchlevel\EventSourcing\Schema\DoctrineSchemaDirector;
+use Patchlevel\EventSourcing\Schema\SchemaDirector;
 
-/** @var DoctrineSchemaDirector $schemaDirector */
+/** @var SchemaDirector $schemaDirector */
 $schemaDirector->drop();
 ```
 Or can give you back which SQL statements would be necessary for this.
 
 ```php
-use Patchlevel\EventSourcing\Schema\DoctrineSchemaDirector;
+use Patchlevel\EventSourcing\Schema\DryRunSchemaDirector;
 
-/** @var DoctrineSchemaDirector $schemaDirector */
+/** @var DryRunSchemaDirector $schemaDirector */
 $sql = $schemaDirector->dryRunDrop();
 ```
 ### Doctrine Migrations
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index 26a4be10..ee93d9a3 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -50,6 +50,11 @@ parameters:
 			count: 1
 			path: src/Store/DoctrineDbalStoreStream.php
 
+		-
+			message: "#^Property Patchlevel\\\\EventSourcing\\\\Store\\\\InMemoryStore\\:\\:\\$messages \\(array\\<int\\<0, max\\>, Patchlevel\\\\EventSourcing\\\\Message\\\\Message\\>\\) does not accept array\\<int, Patchlevel\\\\EventSourcing\\\\Message\\\\Message\\>\\.$#"
+			count: 1
+			path: src/Store/InMemoryStore.php
+
 		-
 			message: "#^Parameter \\#2 \\$playhead of class Patchlevel\\\\EventSourcing\\\\Store\\\\StreamHeader constructor expects int\\<1, max\\>\\|null, int\\|null given\\.$#"
 			count: 1
diff --git a/src/Store/Criteria/StreamCriterion.php b/src/Store/Criteria/StreamCriterion.php
index 070c1c83..bbe5eecd 100644
--- a/src/Store/Criteria/StreamCriterion.php
+++ b/src/Store/Criteria/StreamCriterion.php
@@ -4,12 +4,19 @@
 
 namespace Patchlevel\EventSourcing\Store\Criteria;
 
+use Patchlevel\EventSourcing\Store\InvalidStreamName;
+
+use function preg_match;
+
 /** @experimental */
 final class StreamCriterion
 {
     public function __construct(
         public readonly string $streamName,
     ) {
+        if (!preg_match('/^[^*]*\*?$/', $this->streamName)) {
+            throw new InvalidStreamName($this->streamName);
+        }
     }
 
     public static function startWith(string $streamName): self
diff --git a/src/Store/InMemoryStore.php b/src/Store/InMemoryStore.php
new file mode 100644
index 00000000..f774e89f
--- /dev/null
+++ b/src/Store/InMemoryStore.php
@@ -0,0 +1,230 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Store;
+
+use Closure;
+use Patchlevel\EventSourcing\Aggregate\AggregateHeader;
+use Patchlevel\EventSourcing\Message\HeaderNotFound;
+use Patchlevel\EventSourcing\Message\Message;
+use Patchlevel\EventSourcing\Store\Criteria\AggregateIdCriterion;
+use Patchlevel\EventSourcing\Store\Criteria\AggregateNameCriterion;
+use Patchlevel\EventSourcing\Store\Criteria\ArchivedCriterion;
+use Patchlevel\EventSourcing\Store\Criteria\Criteria;
+use Patchlevel\EventSourcing\Store\Criteria\FromIndexCriterion;
+use Patchlevel\EventSourcing\Store\Criteria\FromPlayheadCriterion;
+use Patchlevel\EventSourcing\Store\Criteria\StreamCriterion;
+
+use function array_filter;
+use function array_map;
+use function array_push;
+use function array_reverse;
+use function array_slice;
+use function array_unique;
+use function array_values;
+use function count;
+use function mb_substr;
+use function str_ends_with;
+use function str_starts_with;
+
+use const ARRAY_FILTER_USE_BOTH;
+
+final class InMemoryStore implements StreamStore
+{
+    /** @param array<positive-int|0, Message> $messages */
+    public function __construct(
+        private array $messages = [],
+    ) {
+    }
+
+    public function load(
+        Criteria|null $criteria = null,
+        int|null $limit = null,
+        int|null $offset = null,
+        bool $backwards = false,
+    ): ArrayStream {
+        $messages = $this->filter($criteria);
+
+        if ($backwards) {
+            $messages = array_reverse($messages);
+        }
+
+        if ($offset !== null) {
+            $messages = array_slice($messages, $offset);
+        }
+
+        if ($limit !== null) {
+            $messages = array_slice($messages, 0, $limit);
+        }
+
+        return new ArrayStream($messages);
+    }
+
+    public function count(Criteria|null $criteria = null): int
+    {
+        return count($this->filter($criteria));
+    }
+
+    public function save(Message ...$messages): void
+    {
+        array_push($this->messages, ...$messages);
+    }
+
+    /**
+     * @param Closure():ClosureReturn $function
+     *
+     * @template ClosureReturn
+     */
+    public function transactional(Closure $function): void
+    {
+        $function();
+    }
+
+    /** @return list<string> */
+    public function streams(): array
+    {
+        return array_values(
+            array_unique(
+                array_filter(
+                    array_map(
+                        static function (Message $message): string|null {
+                            try {
+                                return $message->header(AggregateHeader::class)->streamName();
+                            } catch (HeaderNotFound) {
+                                try {
+                                    return $message->header(StreamHeader::class)->streamName;
+                                } catch (HeaderNotFound) {
+                                    return null;
+                                }
+                            }
+                        },
+                        $this->messages,
+                    ),
+                    static fn (string|null $streamName): bool => $streamName !== null,
+                ),
+            ),
+        );
+    }
+
+    public function remove(string $streamName): void
+    {
+        $this->messages = array_values(
+            array_filter(
+                $this->messages,
+                static function (Message $message) use ($streamName): bool {
+                    try {
+                        return $message->header(AggregateHeader::class)->streamName() !== $streamName;
+                    } catch (HeaderNotFound) {
+                        try {
+                            return $message->header(StreamHeader::class)->streamName !== $streamName;
+                        } catch (HeaderNotFound) {
+                            return true;
+                        }
+                    }
+                },
+            ),
+        );
+    }
+
+    /** @return array<positive-int|0, Message> */
+    private function filter(Criteria|null $criteria): array
+    {
+        if (!$criteria) {
+            return $this->messages;
+        }
+
+        return array_filter(
+            $this->messages,
+            static function (Message $message, int $index) use ($criteria): bool {
+                foreach ($criteria->all() as $criterion) {
+                    switch ($criterion::class) {
+                        case AggregateIdCriterion::class:
+                            try {
+                                if ($message->header(AggregateHeader::class)->aggregateId !== $criterion->aggregateId) {
+                                    return false;
+                                }
+                            } catch (HeaderNotFound) {
+                                return false;
+                            }
+
+                            break;
+                        case AggregateNameCriterion::class:
+                            try {
+                                if ($message->header(AggregateHeader::class)->aggregateName !== $criterion->aggregateName) {
+                                    return false;
+                                }
+                            } catch (HeaderNotFound) {
+                                return false;
+                            }
+
+                            break;
+                        case StreamCriterion::class:
+                            if ($criterion->streamName === '*') {
+                                break;
+                            }
+
+                            try {
+                                $messageStreamName = $message->header(AggregateHeader::class)->streamName();
+                            } catch (HeaderNotFound) {
+                                try {
+                                    $messageStreamName = $message->header(StreamHeader::class)->streamName;
+                                } catch (HeaderNotFound) {
+                                    return false;
+                                }
+                            }
+
+                            if (str_ends_with($criterion->streamName, '*')) {
+                                if (!str_starts_with($messageStreamName, mb_substr($criterion->streamName, 0, -1))) {
+                                    return false;
+                                }
+
+                                break;
+                            }
+
+                            if ($messageStreamName !== $criterion->streamName) {
+                                return false;
+                            }
+
+                            break;
+                        case FromPlayheadCriterion::class:
+                            $playhead = null;
+
+                            try {
+                                $playhead = $message->header(AggregateHeader::class)->playhead;
+                            } catch (HeaderNotFound) {
+                                try {
+                                    $playhead = $message->header(StreamHeader::class)->playhead;
+                                } catch (HeaderNotFound) {
+                                    return false;
+                                }
+                            }
+
+                            if ($playhead < $criterion->fromPlayhead) {
+                                return false;
+                            }
+
+                            break;
+                        case ArchivedCriterion::class:
+                            if (!$message->hasHeader(ArchivedHeader::class) === $criterion->archived) {
+                                return false;
+                            }
+
+                            break;
+                        case FromIndexCriterion::class:
+                            if ($index < $criterion->fromIndex) {
+                                return false;
+                            }
+
+                            break;
+                        default:
+                            throw new UnsupportedCriterion($criterion::class);
+                    }
+                }
+
+                return true;
+            },
+            ARRAY_FILTER_USE_BOTH,
+        );
+    }
+}
diff --git a/src/Store/StreamDoctrineDbalStore.php b/src/Store/StreamDoctrineDbalStore.php
index e9fa93b4..d9c1cd16 100644
--- a/src/Store/StreamDoctrineDbalStore.php
+++ b/src/Store/StreamDoctrineDbalStore.php
@@ -44,7 +44,6 @@
 use function is_string;
 use function mb_substr;
 use function sprintf;
-use function str_contains;
 use function str_ends_with;
 
 /** @experimental */
@@ -149,14 +148,8 @@ private function applyCriteria(QueryBuilder $builder, Criteria $criteria): void
                     }
 
                     if (str_ends_with($criterion->streamName, '*')) {
-                        $streamName = mb_substr($criterion->streamName, 0, -1);
-
-                        if (str_contains($streamName, '*')) {
-                            throw new InvalidStreamName($criterion->streamName);
-                        }
-
                         $builder->andWhere('stream LIKE :stream');
-                        $builder->setParameter('stream', $streamName . '%');
+                        $builder->setParameter('stream', mb_substr($criterion->streamName, 0, -1) . '%');
 
                         break;
                     }
diff --git a/tests/Unit/Store/InMemoryStoreTest.php b/tests/Unit/Store/InMemoryStoreTest.php
new file mode 100644
index 00000000..626918ba
--- /dev/null
+++ b/tests/Unit/Store/InMemoryStoreTest.php
@@ -0,0 +1,350 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Tests\Unit\Store;
+
+use DateTimeImmutable;
+use Patchlevel\EventSourcing\Aggregate\AggregateHeader;
+use Patchlevel\EventSourcing\Message\Message;
+use Patchlevel\EventSourcing\Store\ArchivedHeader;
+use Patchlevel\EventSourcing\Store\Criteria\AggregateIdCriterion;
+use Patchlevel\EventSourcing\Store\Criteria\AggregateNameCriterion;
+use Patchlevel\EventSourcing\Store\Criteria\ArchivedCriterion;
+use Patchlevel\EventSourcing\Store\Criteria\Criteria;
+use Patchlevel\EventSourcing\Store\Criteria\FromIndexCriterion;
+use Patchlevel\EventSourcing\Store\Criteria\FromPlayheadCriterion;
+use Patchlevel\EventSourcing\Store\Criteria\StreamCriterion;
+use Patchlevel\EventSourcing\Store\InMemoryStore;
+use Patchlevel\EventSourcing\Store\StreamHeader;
+use Patchlevel\EventSourcing\Store\UnsupportedCriterion;
+use Patchlevel\EventSourcing\Tests\Unit\Fixture\ProfileId;
+use Patchlevel\EventSourcing\Tests\Unit\Fixture\ProfileVisited;
+use PHPUnit\Framework\TestCase;
+use Prophecy\PhpUnit\ProphecyTrait;
+use stdClass;
+
+use function iterator_to_array;
+
+/** @covers \Patchlevel\EventSourcing\Store\InMemoryStore */
+final class InMemoryStoreTest extends TestCase
+{
+    use ProphecyTrait;
+
+    public function testLoadEmpty(): void
+    {
+        $store = new InMemoryStore();
+        $stream = $store->load();
+
+        self::assertCount(0, $stream);
+    }
+
+    public function testLoadMessages(): void
+    {
+        $expected = [
+            new Message(new ProfileVisited(ProfileId::fromString('1'))),
+            new Message(new ProfileVisited(ProfileId::fromString('2'))),
+        ];
+
+        $store = new InMemoryStore($expected);
+
+        $stream = $store->load();
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame($expected, $messages);
+    }
+
+    public function testLoadByAggregateId(): void
+    {
+        $message1 = (new Message(new ProfileVisited(ProfileId::fromString('1'))))
+            ->withHeader(new AggregateHeader('profile', '1', 1, new DateTimeImmutable()));
+        $message2 = (new Message(new ProfileVisited(ProfileId::fromString('2'))))
+            ->withHeader(new AggregateHeader('profile', '2', 1, new DateTimeImmutable()));
+        $message3 = new Message(new ProfileVisited(ProfileId::fromString('3')));
+
+        $store = new InMemoryStore([$message1, $message2, $message3]);
+
+        $stream = $store->load(new Criteria(new AggregateIdCriterion('2')));
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message2], $messages);
+    }
+
+    public function testLoadByAggregateName(): void
+    {
+        $message1 = (new Message(new ProfileVisited(ProfileId::fromString('1'))))
+            ->withHeader(new AggregateHeader('foo', '1', 1, new DateTimeImmutable()));
+        $message2 = (new Message(new ProfileVisited(ProfileId::fromString('2'))))
+            ->withHeader(new AggregateHeader('bar', '2', 1, new DateTimeImmutable()));
+        $message3 = new Message(new ProfileVisited(ProfileId::fromString('3')));
+
+        $store = new InMemoryStore([$message1, $message2, $message3]);
+
+        $stream = $store->load(new Criteria(new AggregateNameCriterion('bar')));
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message2], $messages);
+    }
+
+    public function testLoadByStreamName(): void
+    {
+        $message1 = (new Message(new ProfileVisited(ProfileId::fromString('1'))))
+            ->withHeader(new StreamHeader('foo'));
+        $message2 = (new Message(new ProfileVisited(ProfileId::fromString('2'))))
+            ->withHeader(new StreamHeader('bar'));
+        $message3 = new Message(new ProfileVisited(ProfileId::fromString('3')));
+
+        $store = new InMemoryStore([$message1, $message2, $message3]);
+
+        $stream = $store->load(new Criteria(new StreamCriterion('bar')));
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message2], $messages);
+    }
+
+    public function testLoadByStreamNameWithLike(): void
+    {
+        $message1 = (new Message(new ProfileVisited(ProfileId::fromString('1'))))
+            ->withHeader(new StreamHeader('foo-3'));
+        $message2 = (new Message(new ProfileVisited(ProfileId::fromString('2'))))
+            ->withHeader(new StreamHeader('bar-1'));
+        $message3 = (new Message(new ProfileVisited(ProfileId::fromString('3'))))
+            ->withHeader(new StreamHeader('bar-2'));
+
+        $store = new InMemoryStore([$message1, $message2, $message3]);
+
+        $stream = $store->load(new Criteria(new StreamCriterion('bar-*')));
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message2, $message3], $messages);
+    }
+
+    public function testLoadFromPlayhead(): void
+    {
+        $message1 = (new Message(new ProfileVisited(ProfileId::fromString('1'))))
+            ->withHeader(new AggregateHeader('foo', '1', 1, new DateTimeImmutable()));
+        $message2 = (new Message(new ProfileVisited(ProfileId::fromString('2'))))
+            ->withHeader(new AggregateHeader('foo', '1', 2, new DateTimeImmutable()));
+        $message3 = (new Message(new ProfileVisited(ProfileId::fromString('3'))))
+            ->withHeader(new StreamHeader('foo-1', 3, new DateTimeImmutable()));
+        $message4 = (new Message(new ProfileVisited(ProfileId::fromString('3'))));
+
+        $store = new InMemoryStore([$message1, $message2, $message3, $message4]);
+
+        $stream = $store->load(new Criteria(new FromPlayheadCriterion(2)));
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message2, $message3], $messages);
+    }
+
+    public function testLoadFromIndex(): void
+    {
+        $message1 = (new Message(new ProfileVisited(ProfileId::fromString('1'))))
+            ->withHeader(new AggregateHeader('foo', '1', 1, new DateTimeImmutable()));
+        $message2 = (new Message(new ProfileVisited(ProfileId::fromString('2'))))
+            ->withHeader(new AggregateHeader('foo', '1', 2, new DateTimeImmutable()));
+        $message3 = (new Message(new ProfileVisited(ProfileId::fromString('3'))))
+            ->withHeader(new StreamHeader('foo-1', 3, new DateTimeImmutable()));
+        $message4 = (new Message(new ProfileVisited(ProfileId::fromString('3'))));
+
+        $store = new InMemoryStore([$message1, $message2, $message3, $message4]);
+
+        $stream = $store->load(new Criteria(new FromIndexCriterion(2)));
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message3, $message4], $messages);
+    }
+
+    public function testLoadByStreamNameWithLikeAll(): void
+    {
+        $message1 = (new Message(new ProfileVisited(ProfileId::fromString('1'))))
+            ->withHeader(new StreamHeader('foo-3'));
+        $message2 = (new Message(new ProfileVisited(ProfileId::fromString('2'))))
+            ->withHeader(new StreamHeader('bar-1'));
+        $message3 = (new Message(new ProfileVisited(ProfileId::fromString('3'))))
+            ->withHeader(new StreamHeader('bar-2'));
+
+        $store = new InMemoryStore([$message1, $message2, $message3]);
+
+        $stream = $store->load(new Criteria(new StreamCriterion('*')));
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message1, $message2, $message3], $messages);
+    }
+
+    public function testLoadArchived(): void
+    {
+        $message1 = (new Message(new ProfileVisited(ProfileId::fromString('1'))))
+            ->withHeader(new ArchivedHeader());
+        $message2 = (new Message(new ProfileVisited(ProfileId::fromString('2'))));
+
+        $store = new InMemoryStore([$message1, $message2]);
+
+        $stream = $store->load(new Criteria(new ArchivedCriterion(true)));
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message1], $messages);
+    }
+
+    public function testLoadUnsupportedCriterion(): void
+    {
+        $store = new InMemoryStore([
+            new Message(new ProfileVisited(ProfileId::fromString('1'))),
+            new Message(new ProfileVisited(ProfileId::fromString('2'))),
+        ]);
+
+        $this->expectException(UnsupportedCriterion::class);
+
+        $store->load(new Criteria(new stdClass()));
+    }
+
+    public function testLoadLimit(): void
+    {
+        $message1 = new Message(new ProfileVisited(ProfileId::fromString('1')));
+        $message2 = new Message(new ProfileVisited(ProfileId::fromString('2')));
+
+        $store = new InMemoryStore([$message1, $message2]);
+
+        $stream = $store->load(null, 1);
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message1], $messages);
+    }
+
+    public function testLoadOffset(): void
+    {
+        $message1 = new Message(new ProfileVisited(ProfileId::fromString('1')));
+        $message2 = new Message(new ProfileVisited(ProfileId::fromString('2')));
+
+        $store = new InMemoryStore([$message1, $message2]);
+
+        $stream = $store->load(null, null, 1);
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message2], $messages);
+    }
+
+    public function testLoadBackwards(): void
+    {
+        $message1 = new Message(new ProfileVisited(ProfileId::fromString('1')));
+        $message2 = new Message(new ProfileVisited(ProfileId::fromString('2')));
+
+        $store = new InMemoryStore([$message1, $message2]);
+
+        $stream = $store->load(null, null, null, true);
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message2, $message1], $messages);
+    }
+
+    public function testCount(): void
+    {
+        $message1 = (new Message(new ProfileVisited(ProfileId::fromString('1'))))
+            ->withHeader(new ArchivedHeader());
+        $message2 = (new Message(new ProfileVisited(ProfileId::fromString('2'))));
+
+        $store = new InMemoryStore([$message1, $message2]);
+
+        self::assertSame(1, $store->count(new Criteria(new ArchivedCriterion(true))));
+    }
+
+    public function testSaveEmpty(): void
+    {
+        $expected = [
+            new Message(new ProfileVisited(ProfileId::fromString('1'))),
+            new Message(new ProfileVisited(ProfileId::fromString('2'))),
+        ];
+
+        $store = new InMemoryStore([]);
+
+        $store->save(...$expected);
+
+        $stream = $store->load();
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame($expected, $messages);
+    }
+
+    public function testSaveWithExistingMessages(): void
+    {
+        $startMessages = [
+            new Message(new ProfileVisited(ProfileId::fromString('1'))),
+            new Message(new ProfileVisited(ProfileId::fromString('2'))),
+        ];
+
+        $message1 = new Message(new ProfileVisited(ProfileId::fromString('3')));
+
+        $store = new InMemoryStore($startMessages);
+
+        $store->save($message1);
+
+        $stream = $store->load();
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([...$startMessages, $message1], $messages);
+    }
+
+    public function testStreams(): void
+    {
+        $message1 = (new Message(new ProfileVisited(ProfileId::fromString('1'))))
+            ->withHeader(new StreamHeader('foo'));
+        $message2 = (new Message(new ProfileVisited(ProfileId::fromString('2'))))
+            ->withHeader(new StreamHeader('bar'));
+        $message3 = (new Message(new ProfileVisited(ProfileId::fromString('3'))))
+            ->withHeader(new StreamHeader('bar'));
+        $message4 = (new Message(new ProfileVisited(ProfileId::fromString('3'))));
+
+        $store = new InMemoryStore([$message1, $message2, $message3, $message4]);
+
+        self::assertSame(['foo', 'bar'], $store->streams());
+    }
+
+    public function testRemove(): void
+    {
+        $message1 = (new Message(new ProfileVisited(ProfileId::fromString('1'))))
+            ->withHeader(new StreamHeader('foo'));
+        $message2 = (new Message(new ProfileVisited(ProfileId::fromString('2'))))
+            ->withHeader(new StreamHeader('bar'));
+        $message3 = (new Message(new ProfileVisited(ProfileId::fromString('3'))))
+            ->withHeader(new StreamHeader('bar'));
+        $message4 = (new Message(new ProfileVisited(ProfileId::fromString('3'))));
+
+        $store = new InMemoryStore([$message1, $message2, $message3, $message4]);
+
+        $store->remove('bar');
+
+        $stream = $store->load();
+
+        $messages = iterator_to_array($stream);
+
+        self::assertSame([$message1, $message4], $messages);
+    }
+
+    public function testTransactional(): void
+    {
+        $called = false;
+
+        $store = new InMemoryStore();
+        $store->transactional(
+            static function () use (&$called): void {
+                $called = true;
+            },
+        );
+
+        self::assertTrue($called);
+    }
+}