Processor::deferredResolve() - Code Metrics - Inspection of "Nested deferred resolvers" - Youshido/GraphQL - Measure and Improve Code Quality continuously with Scrutinizer

Completed
Pull Request — master (#200)

by Sebastian
created 2018-02-08 13:25 UTC
Processor::deferredResolve() A

↳ Parent: Processor
Complexity

Conditions	4
Paths	3
Size

Total Lines	21
Code Lines	11
Duplication

Lines	0
Ratio	0 %
Code Coverage

Tests	9
CRAP Score	4.016
Importance

Changes
Metric	Value
dl	0
loc	21
ccs	9
cts	10
cp	0.9
rs	9.0534
c	0
b	0
f	0
cc	4
eloc	11
nc	3
nop	3
crap	4.016
<?php
/**
 * Date: 03.11.16
 *
 * @author Portey Vasil <[email protected]>
 */

namespace Youshido\GraphQL\Execution;


use Youshido\GraphQL\Exception\ResolveException;
use Youshido\GraphQL\Execution\Container\Container;
use Youshido\GraphQL\Execution\Context\ExecutionContext;
use Youshido\GraphQL\Execution\Visitor\MaxComplexityQueryVisitor;
use Youshido\GraphQL\Field\Field;
use Youshido\GraphQL\Field\FieldInterface;
use Youshido\GraphQL\Field\InputField;
use Youshido\GraphQL\Parser\Ast\ArgumentValue\InputList as AstInputList;
use Youshido\GraphQL\Parser\Ast\ArgumentValue\InputObject as AstInputObject;
use Youshido\GraphQL\Parser\Ast\ArgumentValue\Literal as AstLiteral;
use Youshido\GraphQL\Parser\Ast\ArgumentValue\VariableReference;
use Youshido\GraphQL\Parser\Ast\Field as AstField;
use Youshido\GraphQL\Parser\Ast\FragmentReference;
use Youshido\GraphQL\Parser\Ast\Interfaces\FieldInterface as AstFieldInterface;
use Youshido\GraphQL\Parser\Ast\Mutation as AstMutation;
use Youshido\GraphQL\Parser\Ast\Query as AstQuery;
use Youshido\GraphQL\Parser\Ast\TypedFragmentReference;
use Youshido\GraphQL\Parser\Parser;
use Youshido\GraphQL\Schema\AbstractSchema;
use Youshido\GraphQL\Type\AbstractType;
use Youshido\GraphQL\Type\Enum\AbstractEnumType;
use Youshido\GraphQL\Type\InputObject\AbstractInputObjectType;
use Youshido\GraphQL\Type\InterfaceType\AbstractInterfaceType;
use Youshido\GraphQL\Type\ListType\AbstractListType;
use Youshido\GraphQL\Type\Object\AbstractObjectType;
use Youshido\GraphQL\Type\Scalar\AbstractScalarType;
use Youshido\GraphQL\Type\TypeMap;
use Youshido\GraphQL\Type\Union\AbstractUnionType;
use Youshido\GraphQL\Validator\RequestValidator\RequestValidator;
use Youshido\GraphQL\Validator\ResolveValidator\ResolveValidator;
use Youshido\GraphQL\Validator\ResolveValidator\ResolveValidatorInterface;

class Processor
{

    const TYPE_NAME_QUERY = '__typename';

    /** @var ExecutionContext */
    protected $executionContext;

    /** @var ResolveValidatorInterface */
    protected $resolveValidator;

    /** @var  array */
    protected $data;

    /** @var int */
    protected $maxComplexity;

    /** @var array DeferredResult[] */
    protected $deferredResultsLeaf = [];

    /** @var array DeferredResult[] */
    protected $deferredResultsComplex = [];

    public function __construct(AbstractSchema $schema)
    {
        if (empty($this->executionContext)) {
            $this->executionContext = new ExecutionContext($schema);
            $this->executionContext->setContainer(new Container());
        }

        $this->resolveValidator = new ResolveValidator($this->executionContext);

    }

    public function processPayload($payload, $variables = [], $reducers = [])
    {
        $this->data = [];

        try {
            $this->parseAndCreateRequest($payload, $variables);

            if ($this->maxComplexity) {
                $reducers[] = new MaxComplexityQueryVisitor($this->maxComplexity);
            }

            if ($reducers) {

                $reducer = new Reducer();
                $reducer->reduceQuery($this->executionContext, $reducers);
            }

            foreach ($this->executionContext->getRequest()->getAllOperations() as $query) {
                if ($operationResult = $this->resolveQuery($query)) {
                    $this->data = array_replace_recursive($this->data, $operationResult);
                };
            }

            // If the processor found any deferred results, resolve them now.
            if (!empty($this->data) && (!empty($this->deferredResultsLeaf) || !empty($this->deferredResultsComplex))) {
              try {
                  while ($deferredResolver = array_shift($this->deferredResultsComplex)) {
                      $deferredResolver->resolve();
                  }

                  // Deferred scalar and enum fields should be resolved last to
                  // pick up as many as possible for a single batch.
                  while ($deferredResolver = array_shift($this->deferredResultsLeaf)) {
                      $deferredResolver->resolve();
                  }
              } catch (\Exception $e) {
                  $this->executionContext->addError($e);
              } finally {
                  $this->data = static::unpackDeferredResults($this->data);
              }
            }

        } catch (\Exception $e) {
            $this->executionContext->addError($e);
        }

        return $this;
    }

    /**
     * Unpack results stored inside deferred resolvers.
     *
     * @param mixed $result
     *   The result ree.
     *
     * @return mixed
     *   The unpacked result.
     */
    public static function unpackDeferredResults($result)
    {
        while ($result instanceof DeferredResult) {
            $result = $result->result;
        }

        if (is_array($result)) {
            foreach ($result as $key => $value) {
                $result[$key] = static::unpackDeferredResults($value);
            }
        }

        return $result;
    }

    protected function resolveQuery(AstQuery $query)
    {
        $schema = $this->executionContext->getSchema();
        $type   = $query instanceof AstMutation ? $schema->getMutationType() : $schema->getQueryType();
        $field  = new Field([
            'name' => $query instanceof AstMutation ? 'mutation' : 'query',
            'type' => $type
        ]);

        if (self::TYPE_NAME_QUERY == $query->getName()) {
            return [$this->getAlias($query) => $type->getName()];
        }

        $this->resolveValidator->assetTypeHasField($type, $query);
        $value = $this->resolveField($field, $query);

        return [$this->getAlias($query) => $value];
    }

    protected function resolveField(FieldInterface $field, AstFieldInterface $ast, $parentValue = null, $fromObject = false)
    {
        try {
            /** @var AbstractObjectType $type */
            $type        = $field->getType();
            $nonNullType = $type->getNullableType();

            if (self::TYPE_NAME_QUERY == $ast->getName()) {
                return $nonNullType->getName();
            }

            $this->resolveValidator->assetTypeHasField($nonNullType, $ast);

            $targetField = $nonNullType->getField($ast->getName());

            $this->prepareAstArguments($targetField, $ast, $this->executionContext->getRequest());
            $this->resolveValidator->assertValidArguments($targetField, $ast, $this->executionContext->getRequest());

            switch ($kind = $targetField->getType()->getNullableType()->getKind()) {
                case TypeMap::KIND_ENUM:
                case TypeMap::KIND_SCALAR:
                    if ($ast instanceof AstQuery && $ast->hasFields()) {
                        throw new ResolveException(sprintf('You can\'t specify fields for scalar type "%s"', $targetField->getType()->getNullableType()->getName()), $ast->getLocation());
                    }

                    return $this->resolveScalar($targetField, $ast, $parentValue);

                case TypeMap::KIND_OBJECT:

                    /** @var $type AbstractObjectType */
                    if (!$ast instanceof AstQuery) {
                        throw new ResolveException(sprintf('You have to specify fields for "%s"', $ast->getName()), $ast->getLocation());
                    }

                    return $this->resolveObject($targetField, $ast, $parentValue);

                case TypeMap::KIND_LIST:
                    return $this->resolveList($targetField, $ast, $parentValue);

                case TypeMap::KIND_UNION:
                case TypeMap::KIND_INTERFACE:

                    if (!$ast instanceof AstQuery) {
                        throw new ResolveException(sprintf('You have to specify fields for "%s"', $ast->getName()), $ast->getLocation());
                    }

                    return $this->resolveComposite($targetField, $ast, $parentValue);

                default:
                    throw new ResolveException(sprintf('Resolving type with kind "%s" not supported', $kind));
            }
        } catch (\Exception $e) {
            $this->executionContext->addError($e);

            if ($fromObject) {
                throw $e;
            }

            return null;
        }
    }

    private function prepareAstArguments(FieldInterface $field, AstFieldInterface $query, Request $request)
    {
        foreach ($query->getArguments() as $astArgument) {
            if ($field->hasArgument($astArgument->getName())) {
                $argumentType = $field->getArgument($astArgument->getName())->getType()->getNullableType();

                $astArgument->setValue($this->prepareArgumentValue($astArgument->getValue(), $argumentType, $request));
            }
        }
    }

    private function prepareArgumentValue($argumentValue, AbstractType $argumentType, Request $request)
    {
        switch ($argumentType->getKind()) {
            case TypeMap::KIND_LIST:
                /** @var $argumentType AbstractListType */
                $result = [];
                if ($argumentValue instanceof AstInputList || is_array($argumentValue)) {
                    $list = is_array($argumentValue) ? $argumentValue : $argumentValue->getValue();
                    foreach ($list as $item) {
                        $result[] = $this->prepareArgumentValue($item, $argumentType->getItemType()->getNullableType(), $request);
                    }
                } else {
                    if ($argumentValue instanceof VariableReference) {
                        return $this->getVariableReferenceArgumentValue($argumentValue, $argumentType, $request);
                    }
                }

                return $result;

            case TypeMap::KIND_INPUT_OBJECT:
                /** @var $argumentType AbstractInputObjectType */
                $result = [];
                if ($argumentValue instanceof AstInputObject) {
                    foreach ($argumentType->getFields() as $field) {
                        /** @var $field Field */
                        if ($field->getConfig()->has('defaultValue')) {
                            $result[$field->getName()] = $field->getType()->getNullableType()->parseInputValue($field->getConfig()->get('defaultValue'));
                        }
                    }
                    foreach ($argumentValue->getValue() as $key => $item) {
                        if ($argumentType->hasField($key)) {
                            $result[$key] = $this->prepareArgumentValue($item, $argumentType->getField($key)->getType()->getNullableType(), $request);
                        } else {
                            $result[$key] = $item;
                        }
                    }
                } else {
                    if ($argumentValue instanceof VariableReference) {
                        return $this->getVariableReferenceArgumentValue($argumentValue, $argumentType, $request);
                    } else {
                        if (is_array($argumentValue)) {
                            return $argumentValue;
                        }
                    }
                }

                return $result;

            case TypeMap::KIND_SCALAR:
            case TypeMap::KIND_ENUM:
                /** @var $argumentValue AstLiteral|VariableReference */
                if ($argumentValue instanceof VariableReference) {
                    return $this->getVariableReferenceArgumentValue($argumentValue, $argumentType, $request);
                } else {
                    if ($argumentValue instanceof AstLiteral) {
                        return $argumentValue->getValue();
                    } else {
                        return $argumentValue;
                    }
                }
        }

        throw new ResolveException('Argument type not supported');
    }

    private function getVariableReferenceArgumentValue(VariableReference $variableReference, AbstractType $argumentType, Request $request)
    {
        $variable = $variableReference->getVariable();
        if ($argumentType->getKind() === TypeMap::KIND_LIST) {
            if (
                (!$variable->isArray() && !is_array($variable->getValue())) ||
                ($variable->getTypeName() !== $argumentType->getNamedType()->getNullableType()->getName()) ||
                ($argumentType->getNamedType()->getKind() === TypeMap::KIND_NON_NULL && $variable->isArrayElementNullable())
            ) {
                throw new ResolveException(sprintf('Invalid variable "%s" type, allowed type is "%s"', $variable->getName(), $argumentType->getNamedType()->getNullableType()->getName()), $variable->getLocation());
            }
        } else {
            if ($variable->getTypeName() !== $argumentType->getName()) {
                throw new ResolveException(sprintf('Invalid variable "%s" type, allowed type is "%s"', $variable->getName(), $argumentType->getName()), $variable->getLocation());
            }
        }

        $requestValue = $request->getVariable($variable->getName());
        if ((null === $requestValue && $variable->isNullable()) && !$request->hasVariable($variable->getName())) {
            throw new ResolveException(sprintf('Variable "%s" does not exist in request', $variable->getName()), $variable->getLocation());
        }

        return $requestValue;
    }


    /**
     * @param FieldInterface     $field
     * @param AbstractObjectType $type
     * @param AstFieldInterface  $ast
     * @param                    $resolvedValue
     * @return array
     */
    private function collectResult(FieldInterface $field, AbstractObjectType $type, $ast, $resolvedValue)
    {
        $result = [];

        foreach ($ast->getFields() as $astField) {
            switch (true) {
                case $astField instanceof TypedFragmentReference:
                    $astName  = $astField->getTypeName();
                    $typeName = $type->getName();

                    if ($typeName !== $astName) {
                        foreach ($type->getInterfaces() as $interface) {
                            if ($interface->getName() === $astName) {
                                $result = array_replace_recursive($result, $this->collectResult($field, $type, $astField, $resolvedValue));
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);

                                break;
                            }
                        }

                        continue 2;
                    }

                    $result = array_replace_recursive($result, $this->collectResult($field, $type, $astField, $resolvedValue));
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);

                    break;

                case $astField instanceof FragmentReference:
                    $astFragment      = $this->executionContext->getRequest()->getFragment($astField->getName());
                    $astFragmentModel = $astFragment->getModel();
                    $typeName         = $type->getName();

                    if ($typeName !== $astFragmentModel) {
                        foreach ($type->getInterfaces() as $interface) {
                            if ($interface->getName() === $astFragmentModel) {
                                $result = array_replace_recursive($result, $this->collectResult($field, $type, $astFragment, $resolvedValue));
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);

                                break;
                            }
                        }

                        continue 2;
                    }

                    $result = array_replace_recursive($result, $this->collectResult($field, $type, $astFragment, $resolvedValue));
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);

                    break;

                default:
                    $result = array_replace_recursive($result, [$this->getAlias($astField) => $this->resolveField($field, $astField, $resolvedValue, true)]);
            }
        }

        return $result;
    }

    /**
     * Apply post-process callbacks to all deferred resolvers.
     */
    protected function deferredResolve($resolvedValue, FieldInterface $field, callable $callback) {
        if ($resolvedValue instanceof DeferredResolverInterface) {
            $deferredResult = new DeferredResult($resolvedValue, function ($resolvedValue) use ($field, $callback) {
                // Allow nested deferred resolvers.
                return $this->deferredResolve($resolvedValue, $field, $callback);
            });

            // Whenever we stumble upon a deferred resolver, add it to the queue
            // to be resolved later.
            $type = $field->getType()->getNamedType();
            if ($type instanceof AbstractScalarType || $type instanceof AbstractEnumType) {
                array_push($this->deferredResultsLeaf, $deferredResult);
            } else {
                array_push($this->deferredResultsComplex, $deferredResult);
            }

            return $deferredResult;
        }
        // For simple values, invoke the callback immediately.
        return $callback($resolvedValue);
    }

    protected function resolveScalar(FieldInterface $field, AstFieldInterface $ast, $parentValue)
    {
        $resolvedValue = $this->doResolve($field, $ast, $parentValue);
        return $this->deferredResolve($resolvedValue, $field, function($resolvedValue) use ($field, $ast, $parentValue) {
            $this->resolveValidator->assertValidResolvedValueForField($field, $resolvedValue);

            /** @var AbstractScalarType $type */
            $type = $field->getType()->getNullableType();

            return $type->serialize($resolvedValue);
        });
    }

    protected function resolveList(FieldInterface $field, AstFieldInterface $ast, $parentValue)
    {
        /** @var AstQuery $ast */
        $resolvedValue = $this->doResolve($field, $ast, $parentValue);

        return $this->deferredResolve($resolvedValue, $field, function ($resolvedValue) use ($field, $ast, $parentValue) {
            $this->resolveValidator->assertValidResolvedValueForField($field, $resolvedValue);

            if (null === $resolvedValue) {
                return null;
            }

            /** @var AbstractListType $type */
            $type     = $field->getType()->getNullableType();
            $itemType = $type->getNamedType();

            $fakeAst = clone $ast;
            if ($fakeAst instanceof AstQuery) {
                $fakeAst->setArguments([]);
            }

            $fakeField = new Field([
              'name' => $field->getName(),
              'type' => $itemType,
              'args' => $field->getArguments(),
            ]);

            $result = [];
            foreach ($resolvedValue as $resolvedValueItem) {
                try {
                    $fakeField->getConfig()->set('resolve', function () use ($resolvedValueItem) {
                        return $resolvedValueItem;
                    });

                    switch ($itemType->getNullableType()->getKind()) {
                        case TypeMap::KIND_ENUM:
                        case TypeMap::KIND_SCALAR:
                            $value = $this->resolveScalar($fakeField, $fakeAst, $resolvedValueItem);

                            break;


                        case TypeMap::KIND_OBJECT:
                            $value = $this->resolveObject($fakeField, $fakeAst, $resolvedValueItem);

                            break;

                        case TypeMap::KIND_UNION:
                        case TypeMap::KIND_INTERFACE:
                            $value = $this->resolveComposite($fakeField, $fakeAst, $resolvedValueItem);

                            break;

                        default:
                            $value = null;
                    }
                } catch (\Exception $e) {
                    $this->executionContext->addError($e);

                    $value = null;
                }

                $result[] = $value;
            }

            return $result;
        });
    }

    protected function resolveObject(FieldInterface $field, AstFieldInterface $ast, $parentValue, $fromUnion = false)
    {
        $resolvedValue = $parentValue;
        if (!$fromUnion) {
            $resolvedValue = $this->doResolve($field, $ast, $parentValue);
        }

        return $this->deferredResolve($resolvedValue, $field, function ($resolvedValue) use ($field, $ast, $parentValue) {
            $this->resolveValidator->assertValidResolvedValueForField($field, $resolvedValue);

            if (null === $resolvedValue) {
                return null;
            }
            /** @var AbstractObjectType $type */
            $type = $field->getType()->getNullableType();

            try {
                return $this->collectResult($field, $type, $ast, $resolvedValue);
            } catch (\Exception $e) {
                return null;
            }
        });
    }

    protected function resolveComposite(FieldInterface $field, AstFieldInterface $ast, $parentValue)
    {
        /** @var AstQuery $ast */
        $resolvedValue = $this->doResolve($field, $ast, $parentValue);
        return $this->deferredResolve($resolvedValue, $field, function ($resolvedValue) use ($field, $ast, $parentValue) {
            $this->resolveValidator->assertValidResolvedValueForField($field, $resolvedValue);

            if (null === $resolvedValue) {
                return null;
            }

            /** @var AbstractUnionType $type */
            $type         = $field->getType()->getNullableType();
            $resolveInfo = new ResolveInfo(
                $field,
                $ast instanceof AstQuery ? $ast->getFields() : [],
                $this->executionContext
            );
            $resolvedType = $type->resolveType($resolvedValue, $resolveInfo);


            if (!$resolvedType) {
                throw new ResolveException('Resolving function must return type');
            }

            if ($type instanceof AbstractInterfaceType) {
                $this->resolveValidator->assertTypeImplementsInterface($resolvedType, $type);
            } else {
                $this->resolveValidator->assertTypeInUnionTypes($resolvedType, $type);
            }

            $fakeField = new Field([
              'name' => $field->getName(),
              'type' => $resolvedType,
              'args' => $field->getArguments(),
            ]);

            return $this->resolveObject($fakeField, $ast, $resolvedValue, true);
        });
    }

    protected function parseAndCreateRequest($payload, $variables = [])
    {
        if (empty($payload)) {
            throw new \InvalidArgumentException('Must provide an operation.');
        }

        $parser  = new Parser();
        $request = new Request($parser->parse($payload), $variables);

        (new RequestValidator())->validate($request);

        $this->executionContext->setRequest($request);
    }

    protected function doResolve(FieldInterface $field, AstFieldInterface $ast, $parentValue = null)
    {
        /** @var AstQuery|AstField $ast */
        $arguments = $this->parseArgumentsValues($field, $ast);
        $astFields = $ast instanceof AstQuery ? $ast->getFields() : [];

        return $field->resolve($parentValue, $arguments, $this->createResolveInfo($field, $astFields));
    }

    protected function parseArgumentsValues(FieldInterface $field, AstFieldInterface $ast)
    {
        $values   = [];
        $defaults = [];

        foreach ($field->getArguments() as $argument) {
            /** @var $argument InputField */
            if ($argument->getConfig()->has('defaultValue')) {
                $defaults[$argument->getName()] = $argument->getConfig()->getDefaultValue();
            }
        }

        foreach ($ast->getArguments() as $astArgument) {
            $argument     = $field->getArgument($astArgument->getName());
            $argumentType = $argument->getType()->getNullableType();

            $values[$argument->getName()] = $argumentType->parseValue($astArgument->getValue());

            if (isset($defaults[$argument->getName()])) {
                unset($defaults[$argument->getName()]);
            }
        }

        return array_merge($values, $defaults);
    }

    private function getAlias(AstFieldInterface $ast)
    {
        return $ast->getAlias() ?: $ast->getName();
    }

    protected function createResolveInfo(FieldInterface $field, array $astFields)
    {
        return new ResolveInfo($field, $astFields, $this->executionContext);
    }


    /**
     * You can access ExecutionContext to check errors and inject dependencies
     *
     * @return ExecutionContext
     */
    public function getExecutionContext()
    {
        return $this->executionContext;
    }

    public function getResponseData()
    {
        $result = [];

        if (!empty($this->data)) {
            $result['data'] = $this->data;
        }

        if ($this->executionContext->hasErrors()) {
            $result['errors'] = $this->executionContext->getErrorsArray();
        }

        return $result;
    }

    /**
     * @return int
     */
    public function getMaxComplexity()
    {
        return $this->maxComplexity;
    }

    /**
     * @param int $maxComplexity
     */
    public function setMaxComplexity($maxComplexity)
    {
        $this->maxComplexity = $maxComplexity;
    }

}

Youshido / GraphQL

Pull Request — master (#200)

Processor::deferredResolve() A

Complexity

Size

Duplication

Code Coverage

Importance

Duplication Side-by-Side

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