Support schema without Query type when using federation

CHANGELOG.md

@@ -9,6 +9,12 @@ You can find and compare releases at the [GitHub release page](https://github.co
 
 ## Unreleased
 
+## v5.22.2
+
+### Fixed
+
+- Support schema without `Query` type when using federation https://github.com/nuwave/lighthouse/pull/1925
+
 ## v5.22.1
 
 ### Fixed

src/Console/MutationCommand.php

@@ -2,13 +2,15 @@
 
 namespace Nuwave\Lighthouse\Console;
 
+use Nuwave\Lighthouse\Schema\RootType;
+
 class MutationCommand extends FieldGeneratorCommand
 {
     protected $name = 'lighthouse:mutation';
 
     protected $description = 'Create a class for a single field on the root Mutation type.';
 
-    protected $type = 'Mutation';
+    protected $type = RootType::MUTATION;
 
     protected function namespaceConfigKey(): string
     {

src/Console/QueryCommand.php

@@ -2,13 +2,15 @@
 
 namespace Nuwave\Lighthouse\Console;
 
+use Nuwave\Lighthouse\Schema\RootType;
+
 class QueryCommand extends FieldGeneratorCommand
 {
     protected $name = 'lighthouse:query';
 
     protected $description = 'Create a class for a single field on the root Query type.';
 
-    protected $type = 'Query';
+    protected $type = RootType::QUERY;
 
     protected function namespaceConfigKey(): string
     {

src/Console/SubscriptionCommand.php

@@ -2,13 +2,15 @@
 
 namespace Nuwave\Lighthouse\Console;
 
+use Nuwave\Lighthouse\Schema\RootType;
+
 class SubscriptionCommand extends LighthouseGeneratorCommand
 {
     protected $name = 'lighthouse:subscription';
 
     protected $description = 'Create a class for a single field on the root Subscription type.';
 
-    protected $type = 'Subscription';
+    protected $type = RootType::SUBSCRIPTION;
 
     protected function namespaceConfigKey(): string
     {

src/Federation/ASTManipulator.php

@@ -7,6 +7,7 @@
 use Nuwave\Lighthouse\Events\ManipulateAST;
 use Nuwave\Lighthouse\Exceptions\FederationException;
 use Nuwave\Lighthouse\Schema\AST\DocumentAST;
+use Nuwave\Lighthouse\Schema\RootType;
 
 class ASTManipulator
 {
@@ -73,8 +74,14 @@ protected function addEntityUnion(DocumentAST &$documentAST): void
 
     protected function addRootFields(DocumentAST &$documentAST): void
     {
+        // In federation it is fine for a schema to not have a user-defined root query type,
+        // since we add two federation related fields to it here.
+        if (! isset($documentAST->types[RootType::QUERY])) {
+            $documentAST->types[RootType::QUERY] = Parser::objectTypeDefinition(/** @lang GraphQL */ 'type Query');
+        }
+
         /** @var \GraphQL\Language\AST\ObjectTypeDefinitionNode $queryType */
-        $queryType = $documentAST->types['Query'];
+        $queryType = $documentAST->types[RootType::QUERY];
 
         $queryType->fields [] = Parser::fieldDefinition(/** @lang GraphQL */ '
         _entities(

src/Federation/FederationPrinter.php

@@ -21,6 +21,7 @@
 use Nuwave\Lighthouse\Federation\Directives\KeyDirective;
 use Nuwave\Lighthouse\Federation\Directives\ProvidesDirective;
 use Nuwave\Lighthouse\Federation\Directives\RequiresDirective;
+use Nuwave\Lighthouse\Schema\RootType;
 
 class FederationPrinter
 {
@@ -53,21 +54,26 @@ public static function print(Schema $schema): string
             unset($types[$type]);
         }
 
-        $originalQueryType = Arr::pull($types, 'Query');
-        $config->setQuery(new ObjectType([
-            'name' => 'Query',
-            'fields' => array_filter(
-                $originalQueryType->getFields(),
-                static function (FieldDefinition $field): bool {
-                    return ! in_array($field->name, static::FEDERATION_FIELDS);
-                }
-            ),
-            'interfaces' => $originalQueryType->getInterfaces(),
-        ]));
-
-        $config->setMutation(Arr::pull($types, 'Mutation'));
-
-        $config->setSubscription(Arr::pull($types, 'Subscription'));
+        /** @var \GraphQL\Type\Definition\ObjectType $originalQueryType */
+        $originalQueryType = Arr::pull($types, RootType::QUERY);
+        $queryFieldsWithoutFederation = array_filter(
+            $originalQueryType->getFields(),
+            static function (FieldDefinition $field): bool {
+                return ! in_array($field->name, static::FEDERATION_FIELDS);
+            }
+        );
+        $newQueryType = count($queryFieldsWithoutFederation) > 0
+            ? new ObjectType([
+                'name' => RootType::QUERY,
+                'fields' => $queryFieldsWithoutFederation,
+                'interfaces' => $originalQueryType->getInterfaces(),
+            ])
+            : null;
+        $config->setQuery($newQueryType);
+
+        $config->setMutation(Arr::pull($types, RootType::MUTATION));
+
+        $config->setSubscription(Arr::pull($types, RootType::SUBSCRIPTION));
 
         $config->setTypes($types);
 

tests/Integration/Federation/FederationSchemaTest.php

@@ -41,6 +41,24 @@ public function testServiceQueryShouldReturnValidSdl(): void
         $this->assertStringContainsString($query, $sdl);
     }
 
+    public function testServiceQueryShouldReturnValidSdlWithoutQuery(): void
+    {
+        $foo = /** @lang GraphQL */ <<<'GRAPHQL'
+type Foo @key(fields: "id") {
+  id: ID! @external
+  foo: String!
+}
+
+GRAPHQL;
+
+        $this->schema = $foo;
+
+        $sdl = $this->_serviceSdl();
+
+        $this->assertStringContainsString($foo, $sdl);
+        $this->assertStringNotContainsString(/** @lang GraphQL */ 'type Query', $sdl);
+    }
+
     public function testFederatedSchemaShouldContainCorrectEntityUnion(): void
     {
         $schema = $this->buildSchema(/** @lang GraphQL */ '

tests/Unit/Federation/SchemaBuilderTest.php

@@ -2,8 +2,8 @@
 
 namespace Tests\Unit\Federation;
 
-use GraphQL\Type\Definition\Directive;
 use GraphQL\Type\Definition\ObjectType;
+use GraphQL\Type\Schema;
 use Nuwave\Lighthouse\Exceptions\FederationException;
 use Nuwave\Lighthouse\Federation\FederationServiceProvider;
 use Tests\TestCase;
@@ -37,6 +37,23 @@ public function testFederatedSchema(): void
         $this->assertTrue($schema->hasType('_Any'));
         $this->assertTrue($schema->hasType('_FieldSet'));
 
+        $this->assertSchemaHasQueryTypeWithFederationFields($schema);
+    }
+
+    public function testAddsQueryTypeIfNotDefined(): void
+    {
+        $schema = $this->buildSchema(/** @lang GraphQL */ '
+        type Foo @key(fields: "id") {
+            id: ID!
+            foo: String!
+        }
+        ');
+
+        $this->assertSchemaHasQueryTypeWithFederationFields($schema);
+    }
+
+    protected function assertSchemaHasQueryTypeWithFederationFields(Schema $schema): void
+    {
         $queryType = $schema->getQueryType();
         $this->assertInstanceOf(ObjectType::class, $queryType);