[Kotlin] Ability to generate sealed interfaces (#869)

kbrooks · Kyle · web-flow · commit d6bd6b45322f · 2021-12-01T22:38:05.000-05:00
Co-authored-by: Kyle &lt;kbrooks@github.com&gt;
diff --git a/docs/codegen-options.md b/docs/codegen-options.md
@@ -57,6 +57,7 @@ See [DirectiveAnnotationsMapping](#option-directiveannotationsmapping)* |
 | `generatedLanguage`                                   | Enum                                                                  | GeneratedLanguage.JAVA                                 | Choose which language you want to generate, Java,Scala,Kotlin were supported. Note that due to language features, there are slight differences in default values between languages.|
 | `generateModelOpenClasses`                            | Boolean                                                               | false                                                  | The class type of the generated model. If true, generate normal classes, else generate data classes. It only support in kotlin(```data class```) and scala(```case class```). Maybe we will consider to support Java ```record``` in the future.|
 | `initializeNullableTypes`                             | Boolean                                                               | false                                                  | Adds a default null value to nullable arguments. Only supported in Kotlin.
+| `generateSealedInterfaces`                            | Boolean                                                               | false                                                  | This applies to generated interfaces on unions and interfaces. If true, generate sealed interfaces, else generate normal ones. It is only supported in Kotlin. |
 | `typesAsInterfaces`                                   | Set(String)                                                           | Empty                                                  | Types that must generated as interfaces should be defined here in format: `TypeName` or `@directive`. E.g.: `User`, `@asInterface`. |
 
 ### Option `graphqlSchemas`
diff --git a/plugins/gradle/example-client-kotlin/build.gradle b/plugins/gradle/example-client-kotlin/build.gradle
@@ -57,6 +57,7 @@ task graphqlCodegenKotlinService(type: GraphQLCodegenGradleTask) {
     apiPackageName = "io.github.dreamylost.api"
     modelPackageName = "io.github.dreamylost.model"
     generateModelOpenClasses = true
+    generateSealedInterfaces = true
     customAnnotationsMapping = [
             "Character": ["@com.fasterxml.jackson.annotation.JsonTypeInfo(use=com.fasterxml.jackson.annotation.JsonTypeInfo.Id.NAME, include=com.fasterxml.jackson.annotation.JsonTypeInfo.As.PROPERTY,property = \"__typename\")",
                           "@com.fasterxml.jackson.annotation.JsonSubTypes(value = arrayOf(" + System.lineSeparator() +
diff --git a/plugins/gradle/graphql-java-codegen-gradle-plugin/src/main/java/io/github/kobylynskyi/graphql/codegen/gradle/GraphQLCodegenGradleTask.java b/plugins/gradle/graphql-java-codegen-gradle-plugin/src/main/java/io/github/kobylynskyi/graphql/codegen/gradle/GraphQLCodegenGradleTask.java
@@ -104,6 +104,7 @@ public class GraphQLCodegenGradleTask extends DefaultTask implements GraphQLCode
     private GeneratedLanguage generatedLanguage = MappingConfigConstants.DEFAULT_GENERATED_LANGUAGE;
     private Boolean generateModelOpenClasses = MappingConfigConstants.DEFAULT_GENERATE_MODEL_OPEN_CLASSES;
     private Boolean initializeNullableTypes = MappingConfigConstants.DEFAULT_INITIALIZE_NULLABLE_TYPES;
+    private Boolean generateSealedInterfaces = MappingConfigConstants.DEFAULT_GENERATE_SEALED_INTERFACES;
 
     public GraphQLCodegenGradleTask() {
         setGroup("codegen");
@@ -857,4 +858,15 @@ public Boolean isInitializeNullableTypes() {
     public void setInitializeNullableTypes(Boolean initializeNullableTypes) {
         this.initializeNullableTypes = initializeNullableTypes;
     }
+
+    @Input
+    @Optional
+    @Override
+    public Boolean isGenerateSealedInterfaces() {
+        return generateSealedInterfaces;
+    }
+
+    public void setGenerateSealedInterfaces(Boolean generateSealedInterfaces) {
+        this.generateSealedInterfaces = generateSealedInterfaces;
+    }
 }
diff --git a/plugins/maven/graphql-java-codegen-maven-plugin/src/main/java/io/github/kobylynskyi/graphql/codegen/GraphQLCodegenMojo.java b/plugins/maven/graphql-java-codegen-maven-plugin/src/main/java/io/github/kobylynskyi/graphql/codegen/GraphQLCodegenMojo.java
@@ -212,6 +212,9 @@ public class GraphQLCodegenMojo extends AbstractMojo implements GraphQLCodegenCo
     @Parameter(defaultValue = MappingConfigConstants.DEFAULT_INITIALIZE_NULLABLE_TYPES_STRING)
     private boolean initializeNullableTypes;
 
+    @Parameter(defaultValue = MappingConfigConstants.DEFAULT_GENERATE_SEALED_INTERFACES_STRING)
+    private boolean generateSealedInterfaces;
+
     @Override
     public void execute() throws MojoExecutionException {
         addCompileSourceRootIfConfigured();
@@ -271,6 +274,7 @@ public void execute() throws MojoExecutionException {
         mappingConfig.setGeneratedLanguage(generatedLanguage);
         mappingConfig.setGenerateModelOpenClasses(isGenerateModelOpenClasses());
         mappingConfig.setInitializeNullableTypes(isInitializeNullableTypes());
+        mappingConfig.setGenerateSealedInterfaces(isGenerateSealedInterfaces());
 
         try {
             instantiateCodegen(mappingConfig).generate();
@@ -612,6 +616,11 @@ public Boolean isInitializeNullableTypes() {
         return initializeNullableTypes;
     }
 
+    @Override
+    public Boolean isGenerateSealedInterfaces() {
+        return generateSealedInterfaces;
+    }
+
     public ParentInterfacesConfig getParentInterfaces() {
         return parentInterfaces;
     }
diff --git a/plugins/sbt/graphql-java-codegen-sbt-plugin/src/main/scala/io/github/dreamylost/graphql/codegen/GraphQLCodegenKeys.scala b/plugins/sbt/graphql-java-codegen-sbt-plugin/src/main/scala/io/github/dreamylost/graphql/codegen/GraphQLCodegenKeys.scala
@@ -124,6 +124,8 @@ trait GraphQLCodegenKeys {
 
   val generateModelOpenClasses = settingKey[Boolean]("The class type of the generated model. If true, generate normal classes, else generate case class.")
 
+  val generateSealedInterfaces = settingKey[Boolean]("If true, generate sealed interfaces for GraphQL unions and interfaces, else generate normal interfaces.")
+
   val generateJacksonTypeIdResolver = settingKey[Boolean]("Specifies whether generated union interfaces should be annotated with a custom Jackson type id resolver generated in model package")
 
   //for version
diff --git a/plugins/sbt/graphql-java-codegen-sbt-plugin/src/main/scala/io/github/dreamylost/graphql/codegen/GraphQLCodegenPlugin.scala b/plugins/sbt/graphql-java-codegen-sbt-plugin/src/main/scala/io/github/dreamylost/graphql/codegen/GraphQLCodegenPlugin.scala
@@ -71,6 +71,7 @@ class GraphQLCodegenPlugin(configuration: Configuration, private[codegen] val co
     graphqlJavaCodegenVersion := None,
     // suffix/prefix/strategies:
     generateModelOpenClasses := MappingConfigConstants.DEFAULT_GENERATE_MODEL_OPEN_CLASSES,
+    generateSealedInterfaces := MappingConfigConstants.DEFAULT_GENERATE_SEALED_INTERFACES,
     generatedLanguage := MappingConfigConstants.DEFAULT_GENERATED_LANGUAGE,
     apiNamePrefix := None,
     apiNameSuffix := MappingConfigConstants.DEFAULT_RESOLVER_SUFFIX,
diff --git a/src/main/java/com/kobylynskyi/graphql/codegen/kotlin/KotlinGraphQLCodegen.java b/src/main/java/com/kobylynskyi/graphql/codegen/kotlin/KotlinGraphQLCodegen.java
@@ -52,6 +52,9 @@ protected void initDefaultValues(MappingConfig mappingConfig) {
         if (mappingConfig.isInitializeNullableTypes() == null) {
             mappingConfig.setInitializeNullableTypes(false);
         }
+        if (mappingConfig.isGenerateSealedInterfaces() == null) {
+            mappingConfig.setGenerateSealedInterfaces(false);
+        }
         if (mappingConfig.getGenerateBuilder() == null) {
             // functional expression
             mappingConfig.setGenerateBuilder(false);
diff --git a/src/main/java/com/kobylynskyi/graphql/codegen/mapper/InterfaceDefinitionToDataModelMapper.java b/src/main/java/com/kobylynskyi/graphql/codegen/mapper/InterfaceDefinitionToDataModelMapper.java
@@ -15,6 +15,7 @@
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.FIELDS;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATED_ANNOTATION;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATED_INFO;
+import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATE_SEALED_INTERFACES;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.IMMUTABLE_MODELS;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.IMPLEMENTS;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.JAVA_DOC;
@@ -63,6 +64,7 @@ public Map<String, Object> map(MappingContext mappingContext, ExtendedInterfaceT
         dataModel.put(ENUM_IMPORT_IT_SELF_IN_SCALA, mappingContext.getEnumImportItSelfInScala());
         dataModel.put(IMMUTABLE_MODELS, mappingContext.getGenerateImmutableModels());
         dataModel.put(PARENT_INTERFACE_PROPERTIES, mappingContext.getParentInterfaceProperties());
+        dataModel.put(GENERATE_SEALED_INTERFACES, mappingContext.isGenerateSealedInterfaces());
         return dataModel;
     }
 
diff --git a/src/main/java/com/kobylynskyi/graphql/codegen/mapper/RequestResponseDefinitionToDataModelMapper.java b/src/main/java/com/kobylynskyi/graphql/codegen/mapper/RequestResponseDefinitionToDataModelMapper.java
@@ -29,6 +29,7 @@
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATED_ANNOTATION;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATED_INFO;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATE_ALL_METHOD_IN_PROJECTION;
+import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATE_SEALED_INTERFACES;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.JAVA_DOC;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.METHOD_NAME;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.OPERATION_NAME;
diff --git a/src/main/java/com/kobylynskyi/graphql/codegen/mapper/TypeDefinitionToDataModelMapper.java b/src/main/java/com/kobylynskyi/graphql/codegen/mapper/TypeDefinitionToDataModelMapper.java
@@ -18,7 +18,6 @@
 import java.util.stream.Collectors;
 
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.ANNOTATIONS;
-import static com.kobylynskyi.graphql.codegen.model.DataModelFields.INITIALIZE_NULLABLE_TYPES;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.BUILDER;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.CLASS_NAME;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.ENUM_IMPORT_IT_SELF_IN_SCALA;
@@ -27,8 +26,10 @@
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATED_ANNOTATION;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATED_INFO;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATE_MODEL_OPEN_CLASSES;
+import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATE_SEALED_INTERFACES;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.IMMUTABLE_MODELS;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.IMPLEMENTS;
+import static com.kobylynskyi.graphql.codegen.model.DataModelFields.INITIALIZE_NULLABLE_TYPES;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.JAVA_DOC;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.PACKAGE;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.PARENT_INTERFACE_PROPERTIES;
@@ -104,6 +105,7 @@ public Map<String, Object> map(MappingContext mappingContext,
         dataModel.put(PARENT_INTERFACE_PROPERTIES, mappingContext.getParentInterfaceProperties());
         dataModel.put(GENERATE_MODEL_OPEN_CLASSES, mappingContext.isGenerateModelOpenClasses());
         dataModel.put(INITIALIZE_NULLABLE_TYPES, mappingContext.isInitializeNullableTypes());
+        dataModel.put(GENERATE_SEALED_INTERFACES, mappingContext.isGenerateSealedInterfaces());
         return dataModel;
     }
 
diff --git a/src/main/java/com/kobylynskyi/graphql/codegen/mapper/UnionDefinitionToDataModelMapper.java b/src/main/java/com/kobylynskyi/graphql/codegen/mapper/UnionDefinitionToDataModelMapper.java
@@ -12,6 +12,7 @@
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.ENUM_IMPORT_IT_SELF_IN_SCALA;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATED_ANNOTATION;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATED_INFO;
+import static com.kobylynskyi.graphql.codegen.model.DataModelFields.GENERATE_SEALED_INTERFACES;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.JAVA_DOC;
 import static com.kobylynskyi.graphql.codegen.model.DataModelFields.PACKAGE;
 
@@ -47,6 +48,7 @@ public Map<String, Object> map(MappingContext mappingContext, ExtendedUnionTypeD
         dataModel.put(GENERATED_ANNOTATION, mappingContext.getAddGeneratedAnnotation());
         dataModel.put(GENERATED_INFO, mappingContext.getGeneratedInformation());
         dataModel.put(ENUM_IMPORT_IT_SELF_IN_SCALA, mappingContext.getEnumImportItSelfInScala());
+        dataModel.put(GENERATE_SEALED_INTERFACES, mappingContext.isGenerateSealedInterfaces());
         return dataModel;
     }
 
diff --git a/src/main/java/com/kobylynskyi/graphql/codegen/model/DataModelFields.java b/src/main/java/com/kobylynskyi/graphql/codegen/model/DataModelFields.java
@@ -37,6 +37,7 @@ public final class DataModelFields {
     public static final String SERIALIZATION_LIBRARY = "serializationLibrary";
     public static final String GENERATE_MODEL_OPEN_CLASSES = "generateModelOpenClasses";
     public static final String INITIALIZE_NULLABLE_TYPES = "initializeNullableTypes";
+    public static final String GENERATE_SEALED_INTERFACES = "generateSealedInterfaces";
 
     private DataModelFields() {
     }
diff --git a/src/main/java/com/kobylynskyi/graphql/codegen/model/GraphQLCodegenConfiguration.java b/src/main/java/com/kobylynskyi/graphql/codegen/model/GraphQLCodegenConfiguration.java
@@ -454,4 +454,11 @@ public interface GraphQLCodegenConfiguration {
      */
     Boolean isInitializeNullableTypes();
 
+    /**
+     * Specifies whether generate sealed interfaces.
+     *
+     * @return <b>false</b> generate sealed interfaces class in kotlin
+     */
+    Boolean isGenerateSealedInterfaces();
+
 }
diff --git a/src/main/java/com/kobylynskyi/graphql/codegen/model/MappingConfig.java b/src/main/java/com/kobylynskyi/graphql/codegen/model/MappingConfig.java
@@ -79,6 +79,7 @@ public class MappingConfig implements GraphQLCodegenConfiguration, Combinable<Ma
 
     private boolean generateModelOpenClasses;
     private boolean initializeNullableTypes;
+    private boolean generateSealedInterfaces;
 
     private GeneratedLanguage generatedLanguage;
 
@@ -188,6 +189,8 @@ public void combine(MappingConfig source) {
                 GraphQLCodegenConfiguration::isGenerateModelOpenClasses);
         initializeNullableTypes = getValueOrDefaultToThis(source,
                 GraphQLCodegenConfiguration::isInitializeNullableTypes);
+        generateSealedInterfaces = getValueOrDefaultToThis(source,
+                GraphQLCodegenConfiguration::isGenerateSealedInterfaces);
     }
 
     private <T> T getValueOrDefaultToThis(MappingConfig source, Function<MappingConfig, T> getValueFunction) {
@@ -666,4 +669,12 @@ public void setInitializeNullableTypes(boolean initializeNullableTypes) {
         this.initializeNullableTypes = initializeNullableTypes;
     }
 
+    public Boolean isGenerateSealedInterfaces() {
+        return generateSealedInterfaces;
+    }
+
+    public void setGenerateSealedInterfaces(boolean generateSealedInterfaces) {
+        this.generateSealedInterfaces = generateSealedInterfaces;
+    }
+
 }
diff --git a/src/main/java/com/kobylynskyi/graphql/codegen/model/MappingConfigConstants.java b/src/main/java/com/kobylynskyi/graphql/codegen/model/MappingConfigConstants.java
@@ -71,6 +71,9 @@ public class MappingConfigConstants {
     //Only supported in kotlin.
     public static final boolean DEFAULT_INITIALIZE_NULLABLE_TYPES = false;
     public static final String DEFAULT_INITIALIZE_NULLABLE_TYPES_STRING = "false";
+    // Only supported in Kotlin
+    public static final boolean DEFAULT_GENERATE_SEALED_INTERFACES = false;
+    public static final String DEFAULT_GENERATE_SEALED_INTERFACES_STRING = "false";
 
 
     private MappingConfigConstants() {
diff --git a/src/main/java/com/kobylynskyi/graphql/codegen/model/MappingConfigDefaultValuesInitializer.java b/src/main/java/com/kobylynskyi/graphql/codegen/model/MappingConfigDefaultValuesInitializer.java
@@ -105,6 +105,9 @@ public static void initDefaultValues(MappingConfig mappingConfig) {
         if (mappingConfig.getGenerateAllMethodInProjection() == null) {
             mappingConfig.setGenerateAllMethodInProjection(MappingConfigConstants.DEFAULT_GENERATE_ALL_METHOD);
         }
+        if (mappingConfig.isGenerateSealedInterfaces() == null) {
+            mappingConfig.setGenerateSealedInterfaces(MappingConfigConstants.DEFAULT_GENERATE_SEALED_INTERFACES);
+        }
     }
 
 }
diff --git a/src/main/java/com/kobylynskyi/graphql/codegen/model/MappingContext.java b/src/main/java/com/kobylynskyi/graphql/codegen/model/MappingContext.java
@@ -62,6 +62,11 @@ public Boolean isInitializeNullableTypes() {
         return config.isInitializeNullableTypes();
     }
 
+    @Override
+    public Boolean isGenerateSealedInterfaces() {
+        return config.isGenerateSealedInterfaces();
+    }
+
     @Override
     public Map<String, String> getCustomTypesMapping() {
         return config.getCustomTypesMapping();
diff --git a/src/main/resources/templates/kotlin-lang/interface.ftl b/src/main/resources/templates/kotlin-lang/interface.ftl
@@ -46,7 +46,7 @@ import ${import}.*
 <#list annotations as annotation>
 @${annotation}
 </#list>
-interface ${className}<#if implements?has_content> : <#list implements as interface>${interface}<#if interface_has_next>, </#if></#list></#if> {
+<#if generateSealedInterfaces>sealed </#if>interface ${className}<#if implements?has_content> : <#list implements as interface>${interface}<#if interface_has_next>, </#if></#list></#if> {
 
 <#if fields?has_content>
     <#list fields as field>
diff --git a/src/main/resources/templates/kotlin-lang/union.ftl b/src/main/resources/templates/kotlin-lang/union.ftl
@@ -19,6 +19,6 @@ package ${package}
 <#list annotations as annotation>
 @${annotation}
 </#list>
-interface ${className} {
+<#if generateSealedInterfaces>sealed </#if>interface ${className} {
 
 }
diff --git a/src/test/java/com/kobylynskyi/graphql/codegen/kotlin/GraphQLCodegenSealedInterfacesTest.java b/src/test/java/com/kobylynskyi/graphql/codegen/kotlin/GraphQLCodegenSealedInterfacesTest.java
@@ -0,0 +1,50 @@
+package com.kobylynskyi.graphql.codegen.kotlin;
+
+import com.kobylynskyi.graphql.codegen.TestUtils;
+import com.kobylynskyi.graphql.codegen.model.GeneratedLanguage;
+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.util.Objects;
+
+import static com.kobylynskyi.graphql.codegen.TestUtils.assertSameTrimmedContent;
+import static com.kobylynskyi.graphql.codegen.TestUtils.getFileByName;
+import static java.util.Collections.singletonList;
+
+class GraphQLCodegenSealedInterfacesTest {
+    private final File outputBuildDir = new File("build/generated");
+    private final File outputScalaClassesDir = new File("build/generated/com/github/graphql");
+    private final MappingConfig mappingConfig = new MappingConfig();
+
+    @BeforeEach
+    void init() {
+        mappingConfig.setGenerateParameterizedFieldsResolvers(false);
+        mappingConfig.setPackageName("com.github.graphql");
+        mappingConfig.setGeneratedLanguage(GeneratedLanguage.KOTLIN);
+        mappingConfig.setGenerateToString(true);
+        mappingConfig.setGenerateApis(true);
+        mappingConfig.setGenerateClient(true);
+        mappingConfig.setGenerateEqualsAndHashCode(true);
+        mappingConfig.setGenerateBuilder(true);
+        mappingConfig.setGenerateSealedInterfaces(true);
+    }
+
+    @AfterEach
+    void cleanup() {
+        Utils.deleteDir(outputBuildDir);
+    }
+
+    @Test
+    void generate_MultipleInterfacesPerType() throws Exception {
+        new KotlinGraphQLCodegen(singletonList("src/test/resources/schemas/github.graphqls"),
+                outputBuildDir, mappingConfig, TestUtils.getStaticGeneratedInfo()).generate();
+        File[] files = Objects.requireNonNull(outputScalaClassesDir.listFiles());
+
+        assertSameTrimmedContent(new File("src/test/resources/expected-classes/kt/Comment_sealed_interfaces.kt.txt"),
+                getFileByName(files, "Comment.kt"));
+    }
+}
diff --git a/src/test/resources/expected-classes/kt/Comment_sealed_interfaces.kt.txt b/src/test/resources/expected-classes/kt/Comment_sealed_interfaces.kt.txt
@@ -0,0 +1,40 @@
+package com.github.graphql
+
+
+@javax.annotation.Generated(
+    value = ["com.kobylynskyi.graphql.codegen.GraphQLCodegen"],
+    date = "2020-12-31T23:59:59-0500"
+)
+sealed interface Comment {
+
+    val author: Actor?
+
+    val authorAssociation: CommentAuthorAssociation
+
+    val body: String
+
+    val bodyHTML: String
+
+    val bodyText: String
+
+    val createdAt: String
+
+    val createdViaEmail: Boolean
+
+    val editor: Actor?
+
+    val id: String
+
+    val includesCreatedEdit: Boolean
+
+    val lastEditedAt: String?
+
+    val publishedAt: String?
+
+    val updatedAt: String
+
+    val userContentEdits: UserContentEditConnection?
+
+    val viewerDidAuthor: Boolean
+
+}
