improve no more middleware exception

Author: DavidBadura

src/Middleware/NoMoreMiddleware.php

@@ -7,11 +7,23 @@
 use Patchlevel\Hydrator\HydratorException;
 use RuntimeException;
 
+use function array_map;
+use function count;
+use function implode;
+use function sprintf;
+
 /** @experimental */
 final class NoMoreMiddleware extends RuntimeException implements HydratorException
 {
-    public function __construct()
+    /** @param non-empty-list<Middleware> $middlewares */
+    public function __construct(array $middlewares)
     {
-        parent::__construct('no more middlewares');
+        parent::__construct(
+            sprintf(
+                'The next middleware in %s was requested, but no further middleware exists. The following middlewares were executed: %s',
+                $middlewares[count($middlewares) - 1]::class,
+                implode(', ', array_map(static fn (Middleware $middleware): string => $middleware::class, $middlewares)),
+            ),
+        );
     }
 }

src/Middleware/Stack.php

@@ -9,7 +9,7 @@ final class Stack
 {
     private int $index = 0;
 
-    /** @param list<Middleware> $middlewares */
+    /** @param non-empty-list<Middleware> $middlewares */
     public function __construct(
         private readonly array $middlewares,
     ) {
@@ -20,7 +20,7 @@ public function next(): Middleware
         $next = $this->middlewares[$this->index] ?? null;
 
         if ($next === null) {
-            throw new NoMoreMiddleware();
+            throw new NoMoreMiddleware($this->middlewares);
         }
 
         $this->index++;

src/MissingMiddlewares.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\Hydrator;
+
+use RuntimeException;
+
+/** @experimental */
+final class MissingMiddlewares extends RuntimeException implements HydratorException
+{
+    public function __construct()
+    {
+        parent::__construct('Missing middlewares.');
+    }
+}

src/StackHydrator.php

@@ -30,6 +30,9 @@ public function __construct(
         private readonly array $middlewares = [new TransformMiddleware()],
         private readonly bool $defaultLazy = false,
     ) {
+        if ($middlewares === []) {
+            throw new MissingMiddlewares();
+        }
     }
 
     /**

tests/Unit/Fixture/DummyMiddleware.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\Hydrator\Tests\Unit\Fixture;
+
+use Patchlevel\Hydrator\Metadata\ClassMetadata;
+use Patchlevel\Hydrator\Middleware\Middleware;
+use Patchlevel\Hydrator\Middleware\Stack;
+
+final class DummyMiddleware implements Middleware
+{
+    /**
+     * @param ClassMetadata<T>     $metadata
+     * @param array<string, mixed> $data
+     * @param array<string, mixed> $context
+     *
+     * @return T
+     *
+     * @template T of object
+     */
+    public function hydrate(ClassMetadata $metadata, array $data, array $context, Stack $stack): object
+    {
+        return $stack->next()->hydrate($metadata, $data, $context, $stack);
+    }
+
+    /**
+     * @param array<string, mixed> $context
+     *
+     * @return array<string, mixed>
+     */
+    public function extract(ClassMetadata $metadata, object $object, array $context, Stack $stack): array
+    {
+        return $stack->next()->extract($metadata, $object, $context, $stack);
+    }
+}

tests/Unit/Middleware/StackTest.php

@@ -4,31 +4,41 @@
 
 namespace Patchlevel\Hydrator\Tests\Unit\Middleware;
 
-use Patchlevel\Hydrator\Middleware\Middleware;
 use Patchlevel\Hydrator\Middleware\NoMoreMiddleware;
 use Patchlevel\Hydrator\Middleware\Stack;
+use Patchlevel\Hydrator\Tests\Unit\Fixture\DummyMiddleware;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\TestCase;
 
 #[CoversClass(Stack::class)]
 final class StackTest extends TestCase
 {
-    public function testEmptyStack(): void
+    public function testStack(): void
     {
-        $this->expectException(NoMoreMiddleware::class);
+        $middleware1 = new DummyMiddleware();
+        $middleware2 = new DummyMiddleware();
 
-        $stack = new Stack([]);
-        $stack->next();
+        $stack = new Stack([$middleware1, $middleware2]);
+
+        self::assertSame($middleware1, $stack->next());
+        self::assertSame($middleware2, $stack->next());
     }
 
-    public function testStack(): void
+    public function testStackThrowsExceptionWhenNoMoreMiddlewareIsAvailable(): void
     {
-        $middleware1 = $this->createStub(Middleware::class);
-        $middleware2 = $this->createStub(Middleware::class);
+        $middleware1 = new DummyMiddleware();
+        $middleware2 = new DummyMiddleware();
 
         $stack = new Stack([$middleware1, $middleware2]);
 
-        self::assertSame($middleware1, $stack->next());
-        self::assertSame($middleware2, $stack->next());
+        $stack->next();
+        $stack->next();
+
+        $this->expectException(NoMoreMiddleware::class);
+        $this->expectExceptionMessage(
+            'The next middleware in Patchlevel\Hydrator\Tests\Unit\Fixture\DummyMiddleware was requested, but no further middleware exists. The following middlewares were executed: Patchlevel\Hydrator\Tests\Unit\Fixture\DummyMiddleware, Patchlevel\Hydrator\Tests\Unit\Fixture\DummyMiddleware',
+        );
+
+        $stack->next();
     }
 }

tests/Unit/Middleware/TransformerMiddlewareTest.php

@@ -30,7 +30,7 @@ public function testHydrate(): void
             $this->classMetadata(ProfileCreated::class),
             ['profileId' => '1', 'email' => 'info@patchlevel.de'],
             [],
-            new Stack([]),
+            new Stack([$middleware]),
         );
 
         self::assertEquals($expected, $event);
@@ -49,7 +49,7 @@ public function testExtract(): void
                 Email::fromString('info@patchlevel.de'),
             ),
             [],
-            new Stack([]),
+            new Stack([$middleware]),
         );
 
         self::assertEquals($expected, $data);

tests/Unit/StackHydratorBuilderTest.php

@@ -51,6 +51,8 @@ public function testAddMetadataEnricherWithPriority(): void
         $builder->addMetadataEnricher($enricher1, 10);
         $builder->addMetadataEnricher($enricher2, 20);
 
+        $builder->addMiddleware($this->createMock(Middleware::class));
+
         $hydrator = $builder->build();
 
         $reflection = new ReflectionProperty(StackHydrator::class, 'metadataFactory');
@@ -74,6 +76,8 @@ public function testAddGuesserWithPriority(): void
         $builder->addGuesser($guesser1, 10);
         $builder->addGuesser($guesser2, 20);
 
+        $builder->addMiddleware($this->createMock(Middleware::class));
+
         $hydrator = $builder->build();
 
         $reflection = new ReflectionProperty(StackHydrator::class, 'metadataFactory');
@@ -103,6 +107,8 @@ public function testEnableDefaultLazy(): void
         $builder = new StackHydratorBuilder();
         $builder->enableDefaultLazy();
 
+        $builder->addMiddleware($this->createMock(Middleware::class));
+
         $hydrator = $builder->build();
 
         $reflection = new ReflectionProperty(StackHydrator::class, 'defaultLazy');
@@ -128,6 +134,7 @@ public function testCachePsr6(): void
 
         $builder = new StackHydratorBuilder();
         $builder->setCache($cache);
+        $builder->addMiddleware($this->createMock(Middleware::class));
 
         $hydrator = $builder->build();
 
@@ -143,6 +150,7 @@ public function testCachePsr16(): void
 
         $builder = new StackHydratorBuilder();
         $builder->setCache($cache);
+        $builder->addMiddleware($this->createMock(Middleware::class));
 
         $hydrator = $builder->build();
 

tests/Unit/StackHydratorTest.php

@@ -11,10 +11,12 @@
 use Patchlevel\Hydrator\ClassNotSupported;
 use Patchlevel\Hydrator\CoreExtension;
 use Patchlevel\Hydrator\DenormalizationFailure;
+use Patchlevel\Hydrator\Metadata\AttributeMetadataFactory;
 use Patchlevel\Hydrator\Metadata\ClassMetadata;
 use Patchlevel\Hydrator\Middleware\Middleware;
 use Patchlevel\Hydrator\Middleware\Stack;
 use Patchlevel\Hydrator\Middleware\TransformMiddleware;
+use Patchlevel\Hydrator\MissingMiddlewares;
 use Patchlevel\Hydrator\NormalizationFailure;
 use Patchlevel\Hydrator\Normalizer\HydratorAwareNormalizer;
 use Patchlevel\Hydrator\StackHydrator;
@@ -58,6 +60,17 @@ public function setUp(): void
         $this->hydrator = new StackHydrator();
     }
 
+    public function testMissingMiddlewares(): void
+    {
+        $this->expectException(MissingMiddlewares::class);
+        $this->expectExceptionMessage('Missing middlewares.');
+
+        new StackHydrator(
+            new AttributeMetadataFactory(),
+            [],
+        );
+    }
+
     public function testExtract(): void
     {
         $event = new ProfileCreated(