Add support for arguments description

src/InputTypeUtils.php

@@ -18,6 +18,7 @@
 use ReflectionNamedType;
 use RuntimeException;
 use TheCodingMachine\GraphQLite\Parameters\ExpandsInputTypeParameters;
+use TheCodingMachine\GraphQLite\Parameters\InputTypeParameter;
 use TheCodingMachine\GraphQLite\Parameters\InputTypeParameterInterface;
 use TheCodingMachine\GraphQLite\Parameters\ParameterInterface;
 
@@ -144,6 +145,9 @@ public static function getInputTypeArgs(array $args): array
             if ($parameter->hasDefaultValue()) {
                 $desc['defaultValue'] = $parameter->getDefaultValue();
             }
+            if ($parameter instanceof InputTypeParameter && $parameter->getDescription()) {
+                $desc['description'] = $parameter->getDescription();
+            }
 
             return $desc;
         }, $inputTypeArgs);

src/Mappers/Parameters/TypeHandler.php

@@ -188,6 +188,8 @@ public function mapParameter(ReflectionParameter $parameter, DocBlock $docBlock,
             }
         }
 
+        $description = $this->getParameterDescriptionFromDocBlock($docBlock, $parameter);
+
         $hasDefaultValue = false;
         $defaultValue = null;
         if ($parameter->allowsNull()) {
@@ -201,13 +203,27 @@ public function mapParameter(ReflectionParameter $parameter, DocBlock $docBlock,
         return new InputTypeParameter(
             name: $parameter->getName(),
             type: $type,
-            description: null,
+            description: $description,
             hasDefaultValue: $hasDefaultValue,
             defaultValue: $defaultValue,
             argumentResolver: $this->argumentResolver,
         );
     }
 
+    private function getParameterDescriptionFromDocBlock(DocBlock $docBlock, ReflectionParameter $parameter): string|null
+    {
+        /** @var DocBlock\Tags\Param[] $paramTags */
+        $paramTags = $docBlock->getTagsByName('param');
+
+        foreach ($paramTags as $paramTag) {
+            if ($paramTag->getVariableName() === $parameter->getName()) {
+                return $paramTag->getDescription()?->render();
+            }
+        }
+
+        return null;
+    }
+
     /**
      * Map class property to a GraphQL type.
      *

tests/FieldsBuilderTest.php

@@ -32,6 +32,7 @@
 use TheCodingMachine\GraphQLite\Fixtures\TestControllerWithReturnDateTime;
 use TheCodingMachine\GraphQLite\Fixtures\TestControllerWithUnionInputParam;
 use TheCodingMachine\GraphQLite\Fixtures\TestEnum;
+use TheCodingMachine\GraphQLite\Fixtures\TestTypeWithDescriptions;
 use TheCodingMachine\GraphQLite\Fixtures\TestTypeWithInvalidPrefetchMethod;
 use TheCodingMachine\GraphQLite\Fixtures\TestControllerWithInvalidReturnType;
 use TheCodingMachine\GraphQLite\Fixtures\TestControllerWithIterableReturnType;
@@ -708,6 +709,20 @@ public function testPrefetchMethod(): void
         $this->assertSame('arg4', $testField->args[3]->name);
     }
 
+    public function testOutputTypeArgumentDescription(): void
+    {
+        $controller = new TestTypeWithDescriptions();
+
+        $queryProvider = $this->buildFieldsBuilder();
+
+        $fields = $queryProvider->getFields($controller);
+        $testField = $fields['customField'];
+
+        $this->assertCount(1, $testField->args);
+        $this->assertSame('arg1', $testField->args[0]->name);
+        $this->assertSame('Test argument description', $testField->args[0]->description);
+    }
+
     public function testSecurityBadQuery(): void
     {
         $controller = new TestControllerWithBadSecurity();

tests/Fixtures/TestTypeWithDescriptions.php

@@ -0,0 +1,24 @@
+<?php
+
+
+namespace TheCodingMachine\GraphQLite\Fixtures;
+
+use TheCodingMachine\GraphQLite\Annotations\Field;
+use TheCodingMachine\GraphQLite\Annotations\Type;
+
+/**
+ * @Type(class=TestObject::class)
+ */
+class TestTypeWithDescriptions
+{
+    /**
+     * @Field()
+     * @param TestObject $test
+     * @param string $arg1 Test argument description
+     * @return string
+     */
+    public function customField(TestObject $test, string $arg1): string
+    {
+        return $test->getTest().$arg1;
+    }
+}

tests/Mappers/Parameters/TypeMapperTest.php

@@ -14,6 +14,7 @@
 use TheCodingMachine\GraphQLite\Fixtures80\UnionOutputType;
 use TheCodingMachine\GraphQLite\Mappers\CannotMapTypeException;
 use TheCodingMachine\GraphQLite\Parameters\DefaultValueParameter;
+use TheCodingMachine\GraphQLite\Parameters\InputTypeParameter;
 use TheCodingMachine\GraphQLite\Reflection\CachedDocBlockFactory;
 
 class TypeMapperTest extends AbstractQueryProviderTest
@@ -98,6 +99,22 @@ public function testHideParameter(): void
         $this->assertSame(24, $param->resolve(null, [], null, $resolveInfo));
     }
 
+    public function testParameterWithDescription(): void
+    {
+        $typeMapper = new TypeHandler($this->getArgumentResolver(), $this->getRootTypeMapper(), $this->getTypeResolver());
+
+        $cachedDocBlockFactory = new CachedDocBlockFactory(new Psr16Cache(new ArrayAdapter()));
+
+        $refMethod = new ReflectionMethod($this, 'withParamDescription');
+        $docBlockObj = $cachedDocBlockFactory->getDocBlock($refMethod);
+        $refParameter = $refMethod->getParameters()[0];
+
+        $parameter = $typeMapper->mapParameter($refParameter, $docBlockObj, null, $this->getAnnotationReader()->getParameterAnnotations($refParameter));
+        $this->assertInstanceOf(InputTypeParameter::class, $parameter);
+        assert($parameter instanceof InputTypeParameter);
+        $this->assertEquals('Foo parameter', $parameter->getDescription());
+    }
+
     public function testHideParameterException(): void
     {
         $typeMapper = new TypeHandler($this->getArgumentResolver(), $this->getRootTypeMapper(), $this->getTypeResolver());
@@ -123,6 +140,14 @@ private function dummy()
 
     }
 
+    /**
+     * @param int $foo Foo parameter
+     */
+    private function withParamDescription(int $foo)
+    {
+
+    }
+
     /**
      * @HideParameter(for="$foo")
      */

tests/QueryFieldTest.php

@@ -9,8 +9,11 @@
 use GraphQL\Type\Definition\Type;
 use PHPUnit\Framework\TestCase;
 use TheCodingMachine\GraphQLite\Fixtures\TestObject;
+use TheCodingMachine\GraphQLite\Middlewares\ServiceResolver;
 use TheCodingMachine\GraphQLite\Middlewares\SourceMethodResolver;
+use TheCodingMachine\GraphQLite\Parameters\InputTypeParameter;
 use TheCodingMachine\GraphQLite\Parameters\ParameterInterface;
+use TheCodingMachine\GraphQLite\Types\ArgumentResolver;
 
 class QueryFieldTest extends TestCase
 {
@@ -31,4 +34,14 @@ public function resolve(?object $source, array $args, mixed $context, ResolveInf
         $this->expectException(Error::class);
         $resolve(new TestObject('foo'), ['arg' => 12], null, $this->createMock(ResolveInfo::class));
     }
+
+    public function testParametersDescription(): void
+    {
+        $sourceResolver = new ServiceResolver(static fn () => null);
+        $queryField = new QueryField('foo', Type::string(), [
+            'arg' => new InputTypeParameter('arg', Type::string(), 'Foo argument', false, null, new ArgumentResolver()),
+        ], $sourceResolver, $sourceResolver, null, null, []);
+
+        $this->assertEquals('Foo argument', $queryField->args[0]->description);
+    }
 }