Support code generation based on introspection query response #165 (#297)

* Support code generation based on introspection query response #165

* 165 introspection query (#298)

* add sbt plugin

* rm log to file

* update

* update readme

* update readme

* update readme

* update client example

* update client example

* update log

* update client example

* add scalaiform

* add scalaiform and publish

* support schemaFinderConfig and parentInterfacesConfig

* update readme license, convert GraphQLCodegen to Def

* update readme

* Create scala.yml

* update scala ci

* update scala ci

* rm scala ci

* rm scala ci

* use publishLocal

* ci support ivy cache

* ci support ivy cache

* fix support ivy cache

* change example project level

* change example project level

* fix path for ci

* fix workflows

* move generate code to src_managed_graphql

* change generate code location to src_managed_graphql

* add sbt-test for plugin

* fix workflows

* fix workflows

* change generate code location to src_managed_graphql

* add watch resource, refactor plugins

* add developer for publish

* add key apiAsyncReturnType and apiAsyncReturnListType,
refactor code, update sbt-test with two options

* add resolvers

* add resolvers for ci

* add resolvers for ci

* add resolvers for ci

* Remove redundant dependencies

* fix support ivy local

* Update github.yml

* fix support ivy local

* update ci

* fix compile failed when generate code  not found in classpath. test in the standard way

* Update github.yml

* 1. update default option code
2. update client example
3. update version to 2.3.0

* update version to 2.3.0

* Merge branch 'master' of github.com:jxnu-liguobin/graphql-java-codegen

* pre release  2.4.0

* next dev 2.4.1-SNAPSHOT
fix example support with v2.4.0 add typename

* add use case with proxy

* add comment

* add Support code

* update README

* add scope on conf key

* add release plugin

* add release plugin

* Setting version to 2.4.2

* Setting version to 2.4.3-SNAPSHOT

* add release plugin (not release)

* upgrade sbt version, update example Deprecated api

* refactor sbt plugin

* refactor sbt plugin

* ♻ Changes for upcoming release 3.0.0 (#276)

* Setting version to 3.0.0

* fix conflict， release3.0.0

* append migration

* append migration

* fix default value, cannot assign a int value to Long(boxing type)

* fix default value, cannot assign a int value to Long(boxing type)

* use new file

* use conversion instead of reflect

* throw exception msg

* add option graphqlQueryIntrospectionResultPath

* Fixes parsing schema and introspection result #296
Co-authored-by: 梦境迷离 <dreamylost@outlook.com>

docs/codegen-options.md

@@ -4,6 +4,7 @@
 | :---------------------------------------------: | :----------------------------------------------------------------: | :-------------------------------------------: | ----------- |
 | `graphqlSchemaPaths`                            | List(String)                                                       | (falls back to `graphqlSchemas`)              | GraphQL schema locations. You can supply multiple paths to GraphQL schemas. To include many schemas from a folder hierarchy, use the `graphqlSchemas` block instead. |
 | `graphqlSchemas`                                | *See [graphqlSchemas](#option-graphqlschemas)*                     | All `.graphqls`/`.graphql` files in resources | Block to define the input GraphQL schemas, when exact paths are too cumbersome. See table below for a list of options. *See [graphqlSchemas](#option-graphqlschemas)* |
+| `graphqlQueryIntrospectionResultPath`           | String                                                             | None                                          | Path to GraphQL Introspection Query result in json format (with root object `__schema` or `data.__schema`). Sample: [sample-introspection-query-result.json](../src/test/resources/introspection-result/sample-introspection-query-result.json)|
 | `outputDir`                                     | String                                                             | None                                          | The output target directory into which code will be generated. |
 | `jsonConfigurationFile`                         | String                                                             | Empty                                         | Path to an external mapping configuration. |
 | `packageName`                                   | String                                                             | Empty                                         | Java package for generated classes. |

plugins/gradle/graphql-java-codegen-gradle-plugin/src/main/java/io/github/kobylynskyi/graphql/codegen/gradle/GraphQLCodegenGradleTask.java

@@ -41,6 +41,7 @@ import java.util.Set;
 public class GraphQLCodegenGradleTask extends DefaultTask implements GraphQLCodegenConfiguration {
 
     private List<String> graphqlSchemaPaths;
+    private String graphqlQueryIntrospectionResultPath;
     private final SchemaFinderConfig graphqlSchemas = new SchemaFinderConfig();
     private File outputDir;
 
@@ -134,7 +135,7 @@ public class GraphQLCodegenGradleTask extends DefaultTask implements GraphQLCode
         mappingConfig.setMutationResolverParentInterface(getMutationResolverParentInterface());
         mappingConfig.setSubscriptionResolverParentInterface(getSubscriptionResolverParentInterface());
 
-        new GraphQLCodegen(getActualSchemaPaths(), outputDir, mappingConfig, buildJsonSupplier()).generate();
+        new GraphQLCodegen(getActualSchemaPaths(), graphqlQueryIntrospectionResultPath, outputDir, mappingConfig, buildJsonSupplier()).generate();
     }
 
     // This is only public so that it can be part of the inputs.
@@ -192,6 +193,16 @@ public class GraphQLCodegenGradleTask extends DefaultTask implements GraphQLCode
         this.graphqlSchemaPaths = graphqlSchemaPaths;
     }
 
+    @InputFile
+    @Optional
+    public String getGraphqlQueryIntrospectionResultPath() {
+        return graphqlQueryIntrospectionResultPath;
+    }
+
+    public void setGraphqlQueryIntrospectionResultPath(String graphqlQueryIntrospectionResultPath) {
+        this.graphqlQueryIntrospectionResultPath = graphqlQueryIntrospectionResultPath;
+    }
+
     @Nested
     @Optional
     public SchemaFinderConfig getGraphqlSchemas() {

plugins/maven/graphql-java-codegen-maven-plugin/src/main/java/io/github/kobylynskyi/graphql/codegen/GraphQLCodegenMojo.java

@@ -37,6 +37,9 @@ public class GraphQLCodegenMojo extends AbstractMojo implements GraphQLCodegenCo
     @Parameter
     private String[] graphqlSchemaPaths;
 
+    @Parameter
+    private String graphqlQueryIntrospectionResultPath;
+
     @Parameter
     private SchemaFinderConfig graphqlSchemas = new SchemaFinderConfig();
 
@@ -212,7 +215,7 @@ public class GraphQLCodegenMojo extends AbstractMojo implements GraphQLCodegenCo
         MappingConfigSupplier mappingConfigSupplier = buildJsonSupplier(jsonConfigurationFile);
 
         try {
-            new GraphQLCodegen(getSchemas(), outputDir, mappingConfig, mappingConfigSupplier).generate();
+            new GraphQLCodegen(getSchemas(), graphqlQueryIntrospectionResultPath, outputDir, mappingConfig, mappingConfigSupplier).generate();
         } catch (Exception e) {
             getLog().error(e);
             throw new MojoExecutionException("Code generation failed. See above for the full exception.");
@@ -265,6 +268,14 @@ public class GraphQLCodegenMojo extends AbstractMojo implements GraphQLCodegenCo
         this.graphqlSchemaPaths = graphqlSchemaPaths;
     }
 
+    public String getGraphqlQueryIntrospectionResultPath() {
+        return graphqlQueryIntrospectionResultPath;
+    }
+
+    public void setGraphqlQueryIntrospectionResultPath(String graphqlQueryIntrospectionResultPath) {
+        this.graphqlQueryIntrospectionResultPath = graphqlQueryIntrospectionResultPath;
+    }
+
     public SchemaFinderConfig getGraphqlSchemas() {
         return graphqlSchemas;
     }

plugins/sbt/graphql-java-codegen-sbt-plugin/src/main/scala/io/github/dreamylost/graphql/codegen/GraphQLCodegenKeys.scala

@@ -104,6 +104,8 @@ trait GraphQLCodegenKeys {
 
   val useOptionalForNullableReturnTypes = settingKey[Boolean]("useOptionalForNullableReturnTypes")
 
+  val graphqlQueryIntrospectionResultPath = settingKey[Option[String]]("graphqlQueryIntrospectionResultPath")
+
   //for version
   val javaxValidationApiVersion = settingKey[Option[String]]("javax-validation-api version")
   val graphqlJavaCodegenVersion = settingKey[Option[String]]("graphql java codegen version")

plugins/sbt/graphql-java-codegen-sbt-plugin/src/main/scala/io/github/dreamylost/graphql/codegen/GraphQLCodegenPlugin.scala

@@ -58,6 +58,7 @@ class GraphQLCodegenPlugin(configuration: Configuration, private[codegen] val co
   //With the implementation of some other plugins, initialization is not necessary,
   //but maybe should be related to the dependency of key. For convenience, this is a conservative operation
   override lazy val globalSettings: Seq[Def.Setting[_]] = Seq(
+    graphqlQueryIntrospectionResultPath := None,
     graphqlSchemas := schemaFinderConfig,
     jsonConfigurationFile := None,
     graphqlSchemaPaths := Seq.empty,
@@ -192,14 +193,18 @@ class GraphQLCodegenPlugin(configuration: Configuration, private[codegen] val co
         val mappingConfigSupplier: JsonMappingConfigSupplier = buildJsonSupplier((jsonConfigurationFile in GraphQLCodegenConfig).value.orNull)
         var result: Seq[File] = Seq.empty
         try {
-          result = new GraphQLCodegen(getSchemas, (outputDir in GraphQLCodegenConfig).value, getMappingConfig().value, mappingConfigSupplier).generate.asScala
+          result = new GraphQLCodegen(
+            getSchemas,
+            (graphqlQueryIntrospectionResultPath in GraphQLCodegenConfig).value.orNull,
+            (outputDir in GraphQLCodegenConfig).value,
+            getMappingConfig().value,
+            mappingConfigSupplier).generate.asScala
           for (file ← result) {
             sLog.value.success(s"${file.getName}")
           }
         } catch {
           case e: Exception ⇒
-            sLog.value.debug(s"${e.getStackTrace}")
-            throw new Exception("Code generation failed. See above for the full exception.")
+            throw new Exception(s"${e.getLocalizedMessage}")
         }
 
         def getSchemas: util.List[String] = {

src/main/java/com/kobylynskyi/graphql/codegen/GraphQLCodegen.java

@@ -52,30 +52,45 @@ import static java.util.stream.Collectors.toList;
 public class GraphQLCodegen {
 
     private final List<String> schemas;
+    private final String introspectionResult;
     private final File outputDir;
     private final MappingConfig mappingConfig;
     private final GeneratedInformation generatedInformation;
 
+    // used in tests
     public GraphQLCodegen(List<String> schemas,
                           File outputDir,
                           MappingConfig mappingConfig,
                           GeneratedInformation generatedInformation) {
-        this(schemas, outputDir, mappingConfig, null, generatedInformation);
+        this(schemas, null, outputDir, mappingConfig, null, generatedInformation);
     }
 
+    // used in tests
+    public GraphQLCodegen(String introspectionResult,
+                          File outputDir,
+                          MappingConfig mappingConfig,
+                          GeneratedInformation generatedInformation) {
+        this(null, introspectionResult, outputDir, mappingConfig, null, generatedInformation);
+    }
+
+    // used in plugins
     public GraphQLCodegen(List<String> schemas,
+                          String introspectionResult,
                           File outputDir,
                           MappingConfig mappingConfig,
                           MappingConfigSupplier externalMappingConfigSupplier) {
-        this(schemas, outputDir, mappingConfig, externalMappingConfigSupplier, new GeneratedInformation());
+        this(schemas, introspectionResult, outputDir, mappingConfig, externalMappingConfigSupplier, new GeneratedInformation());
     }
 
+    // used by other constructors
     public GraphQLCodegen(List<String> schemas,
+                          String introspectionResult,
                           File outputDir,
                           MappingConfig mappingConfig,
                           MappingConfigSupplier externalMappingConfigSupplier,
                           GeneratedInformation generatedInformation) {
         this.schemas = schemas;
+        this.introspectionResult = introspectionResult;
         this.outputDir = outputDir;
         this.mappingConfig = mappingConfig;
         this.mappingConfig.combine(externalMappingConfigSupplier != null ? externalMappingConfigSupplier.get() : null);
@@ -155,7 +170,12 @@ public class GraphQLCodegen {
         }
     }
 
-    private static void validateConfigs(MappingConfig mappingConfig) {
+    private void validateConfigs(MappingConfig mappingConfig) {
+        if (!Utils.isEmpty(schemas) && introspectionResult != null ||
+                (Utils.isEmpty(schemas) && introspectionResult == null)) {
+            // either schemas or introspection result should be provided
+            throw new IllegalArgumentException("Either graphql schema path or introspection result path should be supplied");
+        }
         if (mappingConfig.getApiRootInterfaceStrategy() == ApiRootInterfaceStrategy.INTERFACE_PER_SCHEMA &&
                 mappingConfig.getApiNamePrefixStrategy() == ApiNamePrefixStrategy.CONSTANT) {
             // we will have a conflict in case there is "type Query" in multiple graphql schema files
@@ -205,13 +225,20 @@ public class GraphQLCodegen {
         GraphQLCodegenFileCreator.prepareOutputDir(outputDir);
         long startTime = System.currentTimeMillis();
         List<File> generatedFiles = Collections.emptyList();
-        if (!schemas.isEmpty()) {
-            ExtendedDocument document = GraphQLDocumentParser.getDocument(mappingConfig, schemas);
+        if (!Utils.isEmpty(schemas)) {
+            ExtendedDocument document = GraphQLDocumentParser.getDocumentFromSchemas(mappingConfig, schemas);
+            initCustomTypeMappings(document.getScalarDefinitions());
+            generatedFiles = processDefinitions(document);
+            System.out.println(String.format("Finished processing %d schema(s) in %d ms", schemas.size(),
+                    System.currentTimeMillis() - startTime));
+        } else if (introspectionResult != null) {
+            ExtendedDocument document = GraphQLDocumentParser.getDocumentFromIntrospectionResult(mappingConfig, introspectionResult);
             initCustomTypeMappings(document.getScalarDefinitions());
             generatedFiles = processDefinitions(document);
+            System.out.println(String.format("Finished processing introspection result in %d ms",
+                    System.currentTimeMillis() - startTime));
         }
-        long elapsed = System.currentTimeMillis() - startTime;
-        System.out.println(String.format("Finished processing %d schema(s) in %d ms", schemas.size(), elapsed));
+
         return generatedFiles;
     }
 

src/main/java/com/kobylynskyi/graphql/codegen/GraphQLDocumentParser.java

 package com.kobylynskyi.graphql.codegen;
 
+import com.fasterxml.jackson.core.type.TypeReference;
 import com.kobylynskyi.graphql.codegen.model.MappingConfig;
 import com.kobylynskyi.graphql.codegen.model.definitions.ExtendedDefinition;
 import com.kobylynskyi.graphql.codegen.model.definitions.ExtendedDocument;
@@ -10,6 +11,7 @@ import com.kobylynskyi.graphql.codegen.model.definitions.ExtendedObjectTypeDefin
 import com.kobylynskyi.graphql.codegen.model.definitions.ExtendedScalarTypeDefinition;
 import com.kobylynskyi.graphql.codegen.model.definitions.ExtendedUnionTypeDefinition;
 import com.kobylynskyi.graphql.codegen.utils.Utils;
+import graphql.introspection.IntrospectionResultToSchema;
 import graphql.language.Definition;
 import graphql.language.Document;
 import graphql.language.EnumTypeDefinition;
@@ -41,7 +43,7 @@ class GraphQLDocumentParser {
     private GraphQLDocumentParser() {
     }
 
-    static ExtendedDocument getDocument(MappingConfig mappingConfig, List<String> schemaPaths) throws IOException {
+    static ExtendedDocument getDocumentFromSchemas(MappingConfig mappingConfig, List<String> schemaPaths) throws IOException {
         Document document = readDocument(schemaPaths);
 
         ExtendedDocumentBuilder extendedDocumentBuilder = new ExtendedDocumentBuilder();
@@ -52,6 +54,25 @@ class GraphQLDocumentParser {
         return extendedDocumentBuilder.build();
     }
 
+    static ExtendedDocument getDocumentFromIntrospectionResult(MappingConfig mappingConfig, String introspectionResult) throws IOException {
+        String introspectionResultContent = Utils.getFileContent(introspectionResult);
+        Map<String, Object> introspectionResultMap = Utils.OBJECT_MAPPER.readValue(introspectionResultContent,
+                new TypeReference<Map<String, Object>>() {
+                });
+        // unwrapping "data" (in case such GraphQL response supplied)
+        if (introspectionResultMap.containsKey("data")) {
+            introspectionResultMap = (Map<String, Object>) introspectionResultMap.get("data");
+        }
+        Document document = new IntrospectionResultToSchema().createSchemaDefinition(introspectionResultMap);
+
+        ExtendedDocumentBuilder extendedDocumentBuilder = new ExtendedDocumentBuilder();
+
+        for (Definition<?> definition : document.getDefinitions()) {
+            processDefinition(mappingConfig, extendedDocumentBuilder, definition);
+        }
+        return extendedDocumentBuilder.build();
+    }
+
     private static void processDefinition(MappingConfig mappingConfig, ExtendedDocumentBuilder extendedDocumentBuilder, Definition<?> definition) {
         if (!(definition instanceof NamedNode)) {
             // the only definition that does not have a name is SchemaDefinition, so skipping it

src/main/java/com/kobylynskyi/graphql/codegen/model/definitions/ExtendedObjectTypeDefinition.java

 package com.kobylynskyi.graphql.codegen.model.definitions;
 
+import graphql.language.Node;
 import graphql.language.ObjectTypeDefinition;
 import graphql.language.ObjectTypeExtensionDefinition;
 
@@ -45,16 +46,26 @@ public class ExtendedObjectTypeDefinition extends ExtendedImplementingTypeDefini
     private Map<String, ExtendedObjectTypeDefinition> groupBySourceLocation(Function<File, String> fileStringFunction) {
         Map<String, ExtendedObjectTypeDefinition> definitionMap = new HashMap<>();
         if (definition != null) {
-            File file = new File(definition.getSourceLocation().getSourceName());
+            File file = new File(getSourceLocationName(definition));
             definitionMap.computeIfAbsent(fileStringFunction.apply(file), d -> new ExtendedObjectTypeDefinition())
                     .setDefinition(definition);
         }
         for (ObjectTypeExtensionDefinition extension : extensions) {
-            File file = new File(extension.getSourceLocation().getSourceName());
+            File file = new File(getSourceLocationName(extension));
             definitionMap.computeIfAbsent(fileStringFunction.apply(file), d -> new ExtendedObjectTypeDefinition())
                     .getExtensions().add(extension);
         }
         return definitionMap;
     }
 
+    /**
+     * Get source location of the node.
+     * In some cases Node does not have a source location defined, so returning "unknown"
+     *
+     * @return source location if present or "unknown" otherwise
+     */
+    private static String getSourceLocationName(Node<?> node) {
+        return node.getSourceLocation() != null ? node.getSourceLocation().getSourceName() : "unknown";
+    }
+
 }

src/main/java/com/kobylynskyi/graphql/codegen/supplier/JsonMappingConfigSupplier.java

 package com.kobylynskyi.graphql.codegen.supplier;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
 import com.kobylynskyi.graphql.codegen.model.MappingConfig;
+import com.kobylynskyi.graphql.codegen.utils.Utils;
 
 import java.io.File;
 import java.io.IOException;
@@ -13,8 +13,6 @@ import java.io.IOException;
  */
 public class JsonMappingConfigSupplier implements MappingConfigSupplier {
 
-    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
-
     private final String jsonConfigFile;
 
     /**
@@ -30,7 +28,7 @@ public class JsonMappingConfigSupplier implements MappingConfigSupplier {
     public MappingConfig get() {
         if (jsonConfigFile != null && !jsonConfigFile.isEmpty()) {
             try {
-                return OBJECT_MAPPER.readValue(new File(jsonConfigFile), MappingConfig.class);
+                return Utils.OBJECT_MAPPER.readValue(new File(jsonConfigFile), MappingConfig.class);
             } catch (IOException e) {
                 throw new IllegalArgumentException(e);
             }

src/main/java/com/kobylynskyi/graphql/codegen/utils/Utils.java

 package com.kobylynskyi.graphql.codegen.utils;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import com.kobylynskyi.graphql.codegen.model.exception.UnableToCreateDirectoryException;
 import com.kobylynskyi.graphql.codegen.model.exception.UnableToDeleteDirectoryException;
 import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLOperation;
@@ -18,6 +19,8 @@ import java.util.Objects;
  */
 public final class Utils {
 
+    public static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
+
     private Utils() {
     }
 

src/test/java/com/kobylynskyi/graphql/codegen/GraphQLCodegenIntrospectionResultTest.java

+package com.kobylynskyi.graphql.codegen;
+
+import com.kobylynskyi.graphql.codegen.model.ApiNamePrefixStrategy;
+import com.kobylynskyi.graphql.codegen.model.ApiRootInterfaceStrategy;
+import com.kobylynskyi.graphql.codegen.model.MappingConfig;
+import com.kobylynskyi.graphql.codegen.utils.Utils;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+
+import static com.kobylynskyi.graphql.codegen.TestUtils.assertSameTrimmedContent;
+import static java.util.stream.Collectors.toList;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class GraphQLCodegenIntrospectionResultTest {
+
+    private final File outputBuildDir = new File("build/generated");
+    private final File outputJavaClassesDir = new File("build/generated/com/kobylynskyi/graphql/test1");
+
+    private MappingConfig mappingConfig;
+
+    @BeforeEach
+    void init() {
+        mappingConfig = new MappingConfig();
+        mappingConfig.setPackageName("com.kobylynskyi.graphql.test1");
+        mappingConfig.setGenerateClient(true);
+    }
+
+    @AfterEach
+    void cleanup() {
+        Utils.deleteDir(outputBuildDir);
+    }
+
+    @Test
+    void generateClientFromIntrospectionResult() throws Exception {
+        new GraphQLCodegen("src/test/resources/introspection-result/sample-introspection-query-result.json",
+                outputBuildDir, mappingConfig, TestUtils.getStaticGeneratedInfo()).generate();
+
+        checkGeneratedFiles();
+    }
+
+    @Test
+    void generateClientFromIntrospectionResultWrappedInData() throws Exception {
+        new GraphQLCodegen("src/test/resources/introspection-result/sample-introspection-query-result-wrapped.json",
+                outputBuildDir, mappingConfig, TestUtils.getStaticGeneratedInfo()).generate();
+
+        checkGeneratedFiles();
+    }
+
+    @Test
+    void generateClientFromIntrospectionResult_SetApiStrategies() throws Exception {
+        mappingConfig.setApiRootInterfaceStrategy(ApiRootInterfaceStrategy.INTERFACE_PER_SCHEMA);
+        mappingConfig.setApiNamePrefixStrategy(ApiNamePrefixStrategy.FOLDER_NAME_AS_PREFIX);
+
+        new GraphQLCodegen("src/test/resources/introspection-result/sample-introspection-query-result.json",
+                outputBuildDir, mappingConfig, TestUtils.getStaticGeneratedInfo()).generate();
+
+        checkGeneratedFiles();
+    }
+
+    private void checkGeneratedFiles() throws IOException {
+        File[] files = Objects.requireNonNull(outputJavaClassesDir.listFiles());
+        List<String> generatedFileNames = Arrays.stream(files).map(File::getName).sorted().collect(toList());
+        assertEquals(Arrays.asList("CreateMutationRequest.java", "CreateMutationResolver.java",
+                "CreateMutationResponse.java", "MutationResolver.java", "Product.java", "ProductByIdQueryRequest.java",
+                "ProductByIdQueryResolver.java", "ProductByIdQueryResponse.java", "ProductInput.java",
+                "ProductResponseProjection.java", "ProductsByIdsQueryRequest.java", "ProductsByIdsQueryResolver.java",
+                "ProductsByIdsQueryResponse.java", "ProductsQueryRequest.java", "ProductsQueryResolver.java",
+                "ProductsQueryResponse.java", "QueryResolver.java", "StockStatus.java"), generatedFileNames);
+
+        for (File file : files) {
+            File expected = new File(String.format("src/test/resources/expected-classes/from-introspection-result/%s.txt", file.getName()));
+            assertSameTrimmedContent(expected, file);
+        }
+    }
+
+}

src/test/java/com/kobylynskyi/graphql/codegen/GraphQLCodegenTest.java

 package com.kobylynskyi.graphql.codegen;
 
+import com.kobylynskyi.graphql.codegen.model.GeneratedInformation;
 import com.kobylynskyi.graphql.codegen.model.MappingConfig;
 import com.kobylynskyi.graphql.codegen.utils.Utils;
 import org.hamcrest.core.StringContains;
@@ -225,12 +226,11 @@ class GraphQLCodegenTest {
     }
 
     @Test
-    void generate_NoSchemas() throws Exception {
-        new GraphQLCodegen(emptyList(),
-                outputBuildDir, mappingConfig, TestUtils.getStaticGeneratedInfo()).generate();
-
-        File[] files = Objects.requireNonNull(outputBuildDir.listFiles());
-        assertEquals(0, files.length);
+    void generate_NoSchemas() {
+        GeneratedInformation staticGeneratedInfo = TestUtils.getStaticGeneratedInfo();
+        List<String> schemas = emptyList();
+        assertThrows(IllegalArgumentException.class, () ->
+                new GraphQLCodegen(schemas, outputBuildDir, mappingConfig, staticGeneratedInfo));
     }
 
     @Test
@@ -239,6 +239,8 @@ class GraphQLCodegenTest {
                 outputBuildDir, mappingConfig, TestUtils.getStaticGeneratedInfo());
 
         assertThrows(NoSuchFileException.class, graphQLCodegen::generate);
+
+        assertEquals(0, Objects.requireNonNull(outputBuildDir.listFiles()).length);
     }
 
     @Test

src/test/resources/expected-classes/from-introspection-result/CreateMutationRequest.java.txt

+package com.kobylynskyi.graphql.test1;
+
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLOperation;
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLOperationRequest;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Objects;
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public class CreateMutationRequest implements GraphQLOperationRequest {
+
+    private static final GraphQLOperation OPERATION_TYPE = GraphQLOperation.MUTATION;
+    private static final String OPERATION_NAME = "create";
+
+    private Map<String, Object> input = new LinkedHashMap<>();
+
+    public CreateMutationRequest() {
+    }
+
+    public void setProductInput(ProductInput productInput) {
+        this.input.put("productInput", productInput);
+    }
+
+    @Override
+    public GraphQLOperation getOperationType() {
+        return OPERATION_TYPE;
+    }
+
+    @Override
+    public String getOperationName() {
+        return OPERATION_NAME;
+    }
+
+    @Override
+    public Map<String, Object> getInput() {
+        return input;
+    }
+
+    @Override
+    public String toString() {
+        return Objects.toString(input);
+    }
+
+    public static class Builder {
+
+        private ProductInput productInput;
+
+        public Builder() {
+        }
+
+        public Builder setProductInput(ProductInput productInput) {
+            this.productInput = productInput;
+            return this;
+        }
+
+
+        public CreateMutationRequest build() {
+            CreateMutationRequest obj = new CreateMutationRequest();
+            obj.setProductInput(productInput);
+            return obj;
+        }
+
+    }
+}

src/test/resources/expected-classes/from-introspection-result/CreateMutationResolver.java.txt

+package com.kobylynskyi.graphql.test1;
+
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public interface CreateMutationResolver {
+
+    Product create(ProductInput productInput) throws Exception;
+
+}
\ No newline at end of file

src/test/resources/expected-classes/from-introspection-result/CreateMutationResponse.java.txt

+package com.kobylynskyi.graphql.test1;
+
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLResult;
+import java.util.Map;
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public class CreateMutationResponse extends GraphQLResult<Map<String, Product>> {
+
+    private static final String OPERATION_NAME = "create";
+
+    public CreateMutationResponse() {
+    }
+
+    public Product create() {
+        Map<String, Product> data = getData();
+        return data != null ? data.get(OPERATION_NAME) : null;
+    }
+
+}

src/test/resources/expected-classes/from-introspection-result/MutationResolver.java.txt

+package com.kobylynskyi.graphql.test1;
+
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public interface MutationResolver {
+
+    Product create(ProductInput productInput) throws Exception;
+
+}
\ No newline at end of file

src/test/resources/expected-classes/from-introspection-result/Product.java.txt

+package com.kobylynskyi.graphql.test1;
+
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLRequestSerializer;
+import java.util.StringJoiner;
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public class Product implements java.io.Serializable {
+
+    @javax.validation.constraints.NotNull
+    private String id;
+    @javax.validation.constraints.NotNull
+    private String title;
+    private String description;
+    @javax.validation.constraints.NotNull
+    private String price;
+    @javax.validation.constraints.NotNull
+    private String sku;
+    private StockStatus stockStatus;
+    @javax.validation.constraints.NotNull
+    private String addedDateTime;
+
+    public Product() {
+    }
+
+    public Product(String id, String title, String description, String price, String sku, StockStatus stockStatus, String addedDateTime) {
+        this.id = id;
+        this.title = title;
+        this.description = description;
+        this.price = price;
+        this.sku = sku;
+        this.stockStatus = stockStatus;
+        this.addedDateTime = addedDateTime;
+    }
+
+    public String getId() {
+        return id;
+    }
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public String getPrice() {
+        return price;
+    }
+    public void setPrice(String price) {
+        this.price = price;
+    }
+
+    public String getSku() {
+        return sku;
+    }
+    public void setSku(String sku) {
+        this.sku = sku;
+    }
+
+    public StockStatus getStockStatus() {
+        return stockStatus;
+    }
+    public void setStockStatus(StockStatus stockStatus) {
+        this.stockStatus = stockStatus;
+    }
+
+    public String getAddedDateTime() {
+        return addedDateTime;
+    }
+    public void setAddedDateTime(String addedDateTime) {
+        this.addedDateTime = addedDateTime;
+    }
+
+
+    @Override
+    public String toString() {
+        StringJoiner joiner = new StringJoiner(", ", "{ ", " }");
+        if (id != null) {
+            joiner.add("id: " + GraphQLRequestSerializer.getEntry(id));
+        }
+        if (title != null) {
+            joiner.add("title: " + GraphQLRequestSerializer.getEntry(title));
+        }
+        if (description != null) {
+            joiner.add("description: " + GraphQLRequestSerializer.getEntry(description));
+        }
+        if (price != null) {
+            joiner.add("price: " + GraphQLRequestSerializer.getEntry(price));
+        }
+        if (sku != null) {
+            joiner.add("sku: " + GraphQLRequestSerializer.getEntry(sku));
+        }
+        if (stockStatus != null) {
+            joiner.add("stockStatus: " + GraphQLRequestSerializer.getEntry(stockStatus));
+        }
+        if (addedDateTime != null) {
+            joiner.add("addedDateTime: " + GraphQLRequestSerializer.getEntry(addedDateTime));
+        }
+        return joiner.toString();
+    }
+
+    public static Product.Builder builder() {
+        return new Product.Builder();
+    }
+
+    public static class Builder {
+
+        private String id;
+        private String title;
+        private String description;
+        private String price;
+        private String sku;
+        private StockStatus stockStatus;
+        private String addedDateTime;
+
+        public Builder() {
+        }
+
+        public Builder setId(String id) {
+            this.id = id;
+            return this;
+        }
+
+        public Builder setTitle(String title) {
+            this.title = title;
+            return this;
+        }
+
+        public Builder setDescription(String description) {
+            this.description = description;
+            return this;
+        }
+
+        public Builder setPrice(String price) {
+            this.price = price;
+            return this;
+        }
+
+        public Builder setSku(String sku) {
+            this.sku = sku;
+            return this;
+        }
+
+        public Builder setStockStatus(StockStatus stockStatus) {
+            this.stockStatus = stockStatus;
+            return this;
+        }
+
+        public Builder setAddedDateTime(String addedDateTime) {
+            this.addedDateTime = addedDateTime;
+            return this;
+        }
+
+
+        public Product build() {
+            return new Product(id, title, description, price, sku, stockStatus, addedDateTime);
+        }
+
+    }
+}

src/test/resources/expected-classes/from-introspection-result/ProductByIdQueryRequest.java.txt

+package com.kobylynskyi.graphql.test1;
+
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLOperation;
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLOperationRequest;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Objects;
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public class ProductByIdQueryRequest implements GraphQLOperationRequest {
+
+    private static final GraphQLOperation OPERATION_TYPE = GraphQLOperation.QUERY;
+    private static final String OPERATION_NAME = "productById";
+
+    private Map<String, Object> input = new LinkedHashMap<>();
+
+    public ProductByIdQueryRequest() {
+    }
+
+    public void setId(String id) {
+        this.input.put("id", id);
+    }
+
+    @Override
+    public GraphQLOperation getOperationType() {
+        return OPERATION_TYPE;
+    }
+
+    @Override
+    public String getOperationName() {
+        return OPERATION_NAME;
+    }
+
+    @Override
+    public Map<String, Object> getInput() {
+        return input;
+    }
+
+    @Override
+    public String toString() {
+        return Objects.toString(input);
+    }
+
+    public static class Builder {
+
+        private String id;
+
+        public Builder() {
+        }
+
+        public Builder setId(String id) {
+            this.id = id;
+            return this;
+        }
+
+
+        public ProductByIdQueryRequest build() {
+            ProductByIdQueryRequest obj = new ProductByIdQueryRequest();
+            obj.setId(id);
+            return obj;
+        }
+
+    }
+}

src/test/resources/expected-classes/from-introspection-result/ProductByIdQueryResolver.java.txt

+package com.kobylynskyi.graphql.test1;
+
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public interface ProductByIdQueryResolver {
+
+    Product productById(String id) throws Exception;
+
+}
\ No newline at end of file

src/test/resources/expected-classes/from-introspection-result/ProductByIdQueryResponse.java.txt

+package com.kobylynskyi.graphql.test1;
+
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLResult;
+import java.util.Map;
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public class ProductByIdQueryResponse extends GraphQLResult<Map<String, Product>> {
+
+    private static final String OPERATION_NAME = "productById";
+
+    public ProductByIdQueryResponse() {
+    }
+
+    public Product productById() {
+        Map<String, Product> data = getData();
+        return data != null ? data.get(OPERATION_NAME) : null;
+    }
+
+}

src/test/resources/expected-classes/from-introspection-result/ProductInput.java.txt

+package com.kobylynskyi.graphql.test1;
+
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLRequestSerializer;
+import java.util.StringJoiner;
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public class ProductInput implements java.io.Serializable {
+
+    @javax.validation.constraints.NotNull
+    private String title;
+    private String description;
+    @javax.validation.constraints.NotNull
+    private String price;
+    @javax.validation.constraints.NotNull
+    private String sku;
+    private StockStatus stockStatus;
+
+    public ProductInput() {
+    }
+
+    public ProductInput(String title, String description, String price, String sku, StockStatus stockStatus) {
+        this.title = title;
+        this.description = description;
+        this.price = price;
+        this.sku = sku;
+        this.stockStatus = stockStatus;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public String getPrice() {
+        return price;
+    }
+    public void setPrice(String price) {
+        this.price = price;
+    }
+
+    public String getSku() {
+        return sku;
+    }
+    public void setSku(String sku) {
+        this.sku = sku;
+    }
+
+    public StockStatus getStockStatus() {
+        return stockStatus;
+    }
+    public void setStockStatus(StockStatus stockStatus) {
+        this.stockStatus = stockStatus;
+    }
+
+
+    @Override
+    public String toString() {
+        StringJoiner joiner = new StringJoiner(", ", "{ ", " }");
+        if (title != null) {
+            joiner.add("title: " + GraphQLRequestSerializer.getEntry(title));
+        }
+        if (description != null) {
+            joiner.add("description: " + GraphQLRequestSerializer.getEntry(description));
+        }
+        if (price != null) {
+            joiner.add("price: " + GraphQLRequestSerializer.getEntry(price));
+        }
+        if (sku != null) {
+            joiner.add("sku: " + GraphQLRequestSerializer.getEntry(sku));
+        }
+        if (stockStatus != null) {
+            joiner.add("stockStatus: " + GraphQLRequestSerializer.getEntry(stockStatus));
+        }
+        return joiner.toString();
+    }
+
+    public static ProductInput.Builder builder() {
+        return new ProductInput.Builder();
+    }
+
+    public static class Builder {
+
+        private String title;
+        private String description;
+        private String price;
+        private String sku;
+        private StockStatus stockStatus;
+
+        public Builder() {
+        }
+
+        public Builder setTitle(String title) {
+            this.title = title;
+            return this;
+        }
+
+        public Builder setDescription(String description) {
+            this.description = description;
+            return this;
+        }
+
+        public Builder setPrice(String price) {
+            this.price = price;
+            return this;
+        }
+
+        public Builder setSku(String sku) {
+            this.sku = sku;
+            return this;
+        }
+
+        public Builder setStockStatus(StockStatus stockStatus) {
+            this.stockStatus = stockStatus;
+            return this;
+        }
+
+
+        public ProductInput build() {
+            return new ProductInput(title, description, price, sku, stockStatus);
+        }
+
+    }
+}

src/test/resources/expected-classes/from-introspection-result/ProductResponseProjection.java.txt

+package com.kobylynskyi.graphql.test1;
+
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLResponseField;
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLResponseProjection;
+
+/**
+ * Response projection for Product
+ */
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public class ProductResponseProjection extends GraphQLResponseProjection {
+
+    public ProductResponseProjection() {
+    }
+
+    public ProductResponseProjection id() {
+        return id(null);
+    }
+
+    public ProductResponseProjection id(String alias) {
+        fields.add(new GraphQLResponseField("id").alias(alias));
+        return this;
+    }
+
+    public ProductResponseProjection title() {
+        return title(null);
+    }
+
+    public ProductResponseProjection title(String alias) {
+        fields.add(new GraphQLResponseField("title").alias(alias));
+        return this;
+    }
+
+    public ProductResponseProjection description() {
+        return description(null);
+    }
+
+    public ProductResponseProjection description(String alias) {
+        fields.add(new GraphQLResponseField("description").alias(alias));
+        return this;
+    }
+
+    public ProductResponseProjection price() {
+        return price(null);
+    }
+
+    public ProductResponseProjection price(String alias) {
+        fields.add(new GraphQLResponseField("price").alias(alias));
+        return this;
+    }
+
+    public ProductResponseProjection sku() {
+        return sku(null);
+    }
+
+    public ProductResponseProjection sku(String alias) {
+        fields.add(new GraphQLResponseField("sku").alias(alias));
+        return this;
+    }
+
+    public ProductResponseProjection stockStatus() {
+        return stockStatus(null);
+    }
+
+    public ProductResponseProjection stockStatus(String alias) {
+        fields.add(new GraphQLResponseField("stockStatus").alias(alias));
+        return this;
+    }
+
+    public ProductResponseProjection addedDateTime() {
+        return addedDateTime(null);
+    }
+
+    public ProductResponseProjection addedDateTime(String alias) {
+        fields.add(new GraphQLResponseField("addedDateTime").alias(alias));
+        return this;
+    }
+
+    public ProductResponseProjection typename() {
+        return typename(null);
+    }
+
+    public ProductResponseProjection typename(String alias) {
+        fields.add(new GraphQLResponseField("__typename").alias(alias));
+        return this;
+    }
+
+
+}

src/test/resources/expected-classes/from-introspection-result/ProductsByIdsQueryRequest.java.txt

+package com.kobylynskyi.graphql.test1;
+
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLOperation;
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLOperationRequest;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Objects;
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public class ProductsByIdsQueryRequest implements GraphQLOperationRequest {
+
+    private static final GraphQLOperation OPERATION_TYPE = GraphQLOperation.QUERY;
+    private static final String OPERATION_NAME = "productsByIds";
+
+    private Map<String, Object> input = new LinkedHashMap<>();
+
+    public ProductsByIdsQueryRequest() {
+    }
+
+    public void setIds(java.util.List<String> ids) {
+        this.input.put("ids", ids);
+    }
+
+    @Override
+    public GraphQLOperation getOperationType() {
+        return OPERATION_TYPE;
+    }
+
+    @Override
+    public String getOperationName() {
+        return OPERATION_NAME;
+    }
+
+    @Override
+    public Map<String, Object> getInput() {
+        return input;
+    }
+
+    @Override
+    public String toString() {
+        return Objects.toString(input);
+    }
+
+    public static class Builder {
+
+        private java.util.List<String> ids;
+
+        public Builder() {
+        }
+
+        public Builder setIds(java.util.List<String> ids) {
+            this.ids = ids;
+            return this;
+        }
+
+
+        public ProductsByIdsQueryRequest build() {
+            ProductsByIdsQueryRequest obj = new ProductsByIdsQueryRequest();
+            obj.setIds(ids);
+            return obj;
+        }
+
+    }
+}

src/test/resources/expected-classes/from-introspection-result/ProductsByIdsQueryResolver.java.txt

+package com.kobylynskyi.graphql.test1;
+
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public interface ProductsByIdsQueryResolver {
+
+    java.util.List<Product> productsByIds(java.util.List<String> ids) throws Exception;
+
+}
\ No newline at end of file

src/test/resources/expected-classes/from-introspection-result/ProductsByIdsQueryResponse.java.txt

+package com.kobylynskyi.graphql.test1;
+
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLResult;
+import java.util.Map;
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public class ProductsByIdsQueryResponse extends GraphQLResult<Map<String, java.util.List<Product>>> {
+
+    private static final String OPERATION_NAME = "productsByIds";
+
+    public ProductsByIdsQueryResponse() {
+    }
+
+    public java.util.List<Product> productsByIds() {
+        Map<String, java.util.List<Product>> data = getData();
+        return data != null ? data.get(OPERATION_NAME) : null;
+    }
+
+}

src/test/resources/expected-classes/from-introspection-result/ProductsQueryRequest.java.txt

+package com.kobylynskyi.graphql.test1;
+
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLOperation;
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLOperationRequest;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Objects;
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public class ProductsQueryRequest implements GraphQLOperationRequest {
+
+    private static final GraphQLOperation OPERATION_TYPE = GraphQLOperation.QUERY;
+    private static final String OPERATION_NAME = "products";
+
+    private Map<String, Object> input = new LinkedHashMap<>();
+
+    public ProductsQueryRequest() {
+    }
+
+    @Override
+    public GraphQLOperation getOperationType() {
+        return OPERATION_TYPE;
+    }
+
+    @Override
+    public String getOperationName() {
+        return OPERATION_NAME;
+    }
+
+    @Override
+    public Map<String, Object> getInput() {
+        return input;
+    }
+
+    @Override
+    public String toString() {
+        return Objects.toString(input);
+    }
+
+    public static class Builder {
+
+
+        public Builder() {
+        }
+
+
+        public ProductsQueryRequest build() {
+            ProductsQueryRequest obj = new ProductsQueryRequest();
+            return obj;
+        }
+
+    }
+}

src/test/resources/expected-classes/from-introspection-result/ProductsQueryResolver.java.txt

+package com.kobylynskyi.graphql.test1;
+
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public interface ProductsQueryResolver {
+
+    java.util.List<Product> products() throws Exception;
+
+}
\ No newline at end of file

src/test/resources/expected-classes/from-introspection-result/ProductsQueryResponse.java.txt

+package com.kobylynskyi.graphql.test1;
+
+import com.kobylynskyi.graphql.codegen.model.graphql.GraphQLResult;
+import java.util.Map;
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public class ProductsQueryResponse extends GraphQLResult<Map<String, java.util.List<Product>>> {
+
+    private static final String OPERATION_NAME = "products";
+
+    public ProductsQueryResponse() {
+    }
+
+    public java.util.List<Product> products() {
+        Map<String, java.util.List<Product>> data = getData();
+        return data != null ? data.get(OPERATION_NAME) : null;
+    }
+
+}

src/test/resources/expected-classes/from-introspection-result/QueryResolver.java.txt

+package com.kobylynskyi.graphql.test1;
+
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public interface QueryResolver {
+
+    java.util.List<Product> products() throws Exception;
+
+    Product productById(String id) throws Exception;
+
+    java.util.List<Product> productsByIds(java.util.List<String> ids) throws Exception;
+
+}
\ No newline at end of file

src/test/resources/expected-classes/from-introspection-result/StockStatus.java.txt

+package com.kobylynskyi.graphql.test1;
+
+@javax.annotation.Generated(
+    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
+    date = "2020-12-31T23:59:59-0500"
+)
+public enum StockStatus {
+
+    IN_STOCK("IN_STOCK"),
+    SPECIAL_ORDER("SPECIAL_ORDER"),
+    BACK_ORDERED("BACK_ORDERED"),
+    COMING_SOON("COMING_SOON"),
+    SOLD_OUT("SOLD_OUT"),
+    DISCONTINUED("DISCONTINUED");
+
+    private final String graphqlName;
+
+    private StockStatus(String graphqlName) {
+        this.graphqlName = graphqlName;
+    }
+
+    @Override
+    public String toString() {
+        return this.graphqlName;
+    }
+
+}
\ No newline at end of file