Adding the option to generate an equals and hashcode method

README.md

@@ -20,12 +20,13 @@ Please refer to:
 | outputDir                 | String             | None                                  | The output target directory into which code will be generated. |
 | apiPackage                | String             | Empty                                 | Java package for generated api classes (Query, Mutation, Subscription). |
 | modelPackage              | String             | Empty                                 | Java package for generated model classes (type, input, interface, enum, union). |
-| generateApis              | Boolean            | True                                  | Java package for generated model classes (type, input, interface, enum, union). |
+| generateApis              | Boolean            | True                                  | Specifies whether api classes should be generated as well as model classes. |
 | customTypesMapping        | Map(String,String) | Empty                                 | Can be used to supply custom mappings for scalars. <br/> Supports:<br/> * Map of (GraphqlObjectName.fieldName) to (JavaType) <br/> * Map of (GraphqlType) to (JavaType) |
 | customAnnotationsMapping  | Map(String,String) | Empty                                 | Can be used to supply custom annotations (serializers) for scalars. <br/> Supports:<br/> * Map of (GraphqlObjectName.fieldName) to (JavaType) <br/> * Map of (GraphqlType) to (JavaType) |
 | modelValidationAnnotation | String             | @javax.validation.<br>constraints.NotNull | Annotation for mandatory (NonNull) fields. Can be null/empty. |
 | modelNamePrefix           | String             | Empty                                 | Sets the prefix for GraphQL model classes (type, input, interface, enum, union). |
 | modelNameSuffix           | String             | Empty                                 | Sets the suffix for GraphQL model classes (type, input, interface, enum, union). |
+| generateEqualsAndHashCode | Boolean            | False                                 | Specifies whether generated model classes should have equals and hashCode methods defined. |
 
 
 ### Inspired by

src/main/java/com/kobylynskyi/graphql/codegen/mapper/InputDefinitionToDataModelMapper.java

@@ -30,6 +30,7 @@ public static Map<String, Object> map(MappingConfig mappingConfig, InputObjectTy
         dataModel.put(CLASS_NAME, MapperUtils.getClassNameWithPrefixAndSuffix(mappingConfig, typeDefinition));
         dataModel.put(NAME, typeDefinition.getName());
         dataModel.put(FIELDS, InputValueDefinitionToParameterMapper.map(mappingConfig, typeDefinition.getInputValueDefinitions(), typeDefinition.getName()));
+        dataModel.put(EQUALS_AND_HASH_CODE, mappingConfig.isGenerateEqualsAndHashCode());
         return dataModel;
     }
 

src/main/java/com/kobylynskyi/graphql/codegen/mapper/TypeDefinitionToDataModelMapper.java

@@ -48,6 +48,7 @@ public static Map<String, Object> map(MappingConfig mappingConfig, ObjectTypeDef
                 .map(i -> FieldDefinitionToParameterMapper.map(mappingConfig, i.getFieldDefinitions(), i.getName()))
                 .forEach(allParameters::addAll);
         dataModel.put(FIELDS, allParameters);
+        dataModel.put(EQUALS_AND_HASH_CODE, mappingConfig.isGenerateEqualsAndHashCode());
 
         return dataModel;
     }

src/main/java/com/kobylynskyi/graphql/codegen/model/DataModelFields.java

@@ -14,4 +14,5 @@ public final class DataModelFields {
     public static final String FIELDS = "fields";
     public static final String IMPLEMENTS = "implements";
     public static final String OPERATIONS = "operations";
+    public static final String EQUALS_AND_HASH_CODE = "equalsAndHashCode";
 }

src/main/java/com/kobylynskyi/graphql/codegen/model/DefaultMappingConfigValues.java

@@ -4,4 +4,5 @@ public class DefaultMappingConfigValues {
 
     public static final String DEFAULT_VALIDATION_ANNOTATION = "javax.validation.constraints.NotNull";
     public static final boolean DEFAULT_GENERATE_APIS = true;
+    public static final boolean DEFAULT_EQUALS_AND_HASHCODE = false;
 }

src/main/java/com/kobylynskyi/graphql/codegen/model/MappingConfig.java

@@ -28,6 +28,7 @@ public class MappingConfig {
     private String modelNamePrefix;
     private String modelNameSuffix;
     private String modelValidationAnnotation = DefaultMappingConfigValues.DEFAULT_VALIDATION_ANNOTATION;
+    private boolean generateEqualsAndHashCode = DefaultMappingConfigValues.DEFAULT_EQUALS_AND_HASHCODE;
 
     public void putCustomTypeMappingIfAbsent(String from, String to) {
         if (customTypesMapping == null) {

src/main/resources/templates/javaClassGraphqlType.ftl

@@ -35,4 +35,26 @@ public class ${className} <#if implements?has_content>implements <#list implemen
     }
 
 </#list>
+<#if equalsAndHashCode>
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (that == null || getClass() != obj.getClass()) {
+            return false;
+        }
+        final ${className} that = (FormField) obj;
+        return <#list fields as field>Objects.equals(${field.name}, that.${field.name}) <#if field_has_next>
+            && </#if></#list>;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(
+<#list fields as field>
+            ${field.name}<#if field_has_next>, </#if>
+</#list>;
+    }
+</#if>
 }

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

@@ -18,6 +18,7 @@
 import static java.util.stream.Collectors.toList;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.fail;
 
 class GraphqlCodegenTest {
@@ -211,6 +212,36 @@ void generate_CustomModelAndApiPackages() throws Exception {
         });
     }
 
+    @Test
+    void generate_EqualsAndHashCode() throws Exception {
+        mappingConfig.setGenerateEqualsAndHashCode(true);
+        mappingConfig.setModelNameSuffix("TO");
+
+
+        generator.generate();
+
+        File[] files = Objects.requireNonNull(outputJavaClassesDir.listFiles());
+        assertNotEquals(files.length, 0);
+
+        for (File eventFile : files) {
+            if (eventFile.getName().endsWith("TO.java")) {
+                String content = Utils.getFileContent(eventFile.getPath());
+
+              if (content.contains("public interface ") || content.contains("public enum ")) {
+                  continue;
+              }
+
+              assertThat(content,
+                  StringContains.containsString("public boolean equals(Object obj)"));
+
+              assertThat(content,
+                  StringContains.containsString("public int hashCode()"));
+            }
+        }
+
+
+    }
+
     @Test
     void generate_NoSchemas() throws Exception {
         generator.setSchemas(Collections.emptyList());