[kotlin-client][kotlin-spring] Fix duplicate discriminator serialization with Jackson used as serialization library

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinSpringServerCodegen.java

@@ -20,7 +20,6 @@
 import com.samskivert.mustache.Mustache;
 import com.samskivert.mustache.Mustache.Lambda;
 import com.samskivert.mustache.Template;
-import io.swagger.v3.oas.models.Components;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.Operation;
 import lombok.Getter;
@@ -425,6 +424,7 @@ public void processOpts() {
         importMapping.put("JsonProperty", "com.fasterxml.jackson.annotation.JsonProperty");
         importMapping.put("JsonSubTypes", "com.fasterxml.jackson.annotation.JsonSubTypes");
         importMapping.put("JsonTypeInfo", "com.fasterxml.jackson.annotation.JsonTypeInfo");
+        importMapping.put("JsonIgnoreProperties", "com.fasterxml.jackson.annotation.JsonIgnoreProperties");
         // import JsonCreator if JsonProperty is imported
         // used later in recursive import in postProcessingModels
         importMapping.put("com.fasterxml.jackson.annotation.JsonProperty", "com.fasterxml.jackson.annotation.JsonCreator");
@@ -827,7 +827,7 @@ public void postProcessModelProperty(CodegenModel model, CodegenProperty propert
         }
 
         if (model.discriminator != null && additionalProperties.containsKey("jackson")) {
-            model.imports.addAll(Arrays.asList("JsonSubTypes", "JsonTypeInfo"));
+            model.imports.addAll(Arrays.asList("JsonSubTypes", "JsonTypeInfo", "JsonIgnoreProperties"));
         }
     }
 

modules/openapi-generator/src/main/resources/kotlin-client/data_class.mustache

@@ -23,6 +23,7 @@ import com.fasterxml.jackson.annotation.JsonEnumDefaultValue
 {{/enumUnknownDefaultCase}}
 import com.fasterxml.jackson.annotation.JsonProperty
 {{#discriminator}}
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties
 import com.fasterxml.jackson.annotation.JsonSubTypes
 import com.fasterxml.jackson.annotation.JsonTypeInfo
 {{/discriminator}}

modules/openapi-generator/src/main/resources/kotlin-client/typeInfoAnnotation.mustache

@@ -1,3 +1,7 @@
+@JsonIgnoreProperties(
+  value = ["{{{discriminator.propertyBaseName}}}"], // ignore manually set {{{discriminator.propertyBaseName}}}, it will be automatically generated by Jackson during serialization
+  allowSetters = true // allows the {{{discriminator.propertyBaseName}}} to be set during deserialization
+)
 @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "{{{discriminator.propertyBaseName}}}", visible = true)
 @JsonSubTypes(
 {{#discriminator.mappedModels}}

modules/openapi-generator/src/main/resources/kotlin-spring/typeInfoAnnotation.mustache

@@ -1,5 +1,8 @@
 {{#jackson}}
-
+@JsonIgnoreProperties(
+  value = ["{{{discriminator.propertyBaseName}}}"], // ignore manually set {{{discriminator.propertyBaseName}}}, it will be automatically generated by Jackson during serialization
+  allowSetters = true // allows the {{{discriminator.propertyBaseName}}} to be set during deserialization
+)
 @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "{{{discriminator.propertyBaseName}}}", visible = true)
 @JsonSubTypes(
   {{#discriminator.mappedModels}}

modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinClientCodegenModelTest.java

@@ -19,17 +19,15 @@
 
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.media.*;
-import lombok.Getter;
-import org.antlr.v4.runtime.*;
+import org.antlr.v4.runtime.CharStreams;
+import org.antlr.v4.runtime.CommonTokenStream;
 import org.antlr.v4.runtime.tree.ParseTree;
 import org.antlr.v4.runtime.tree.ParseTreeWalker;
 import org.openapitools.codegen.*;
 import org.openapitools.codegen.antlr4.KotlinLexer;
 import org.openapitools.codegen.antlr4.KotlinParser;
-import org.openapitools.codegen.antlr4.KotlinParserBaseListener;
 import org.openapitools.codegen.config.CodegenConfigurator;
 import org.openapitools.codegen.languages.KotlinClientCodegen;
-import org.openapitools.codegen.languages.KotlinServerCodegen;
 import org.openapitools.codegen.testutils.ConfigAssert;
 import org.testng.Assert;
 import org.testng.annotations.DataProvider;
@@ -45,8 +43,6 @@
 import java.util.Map;
 
 import static org.openapitools.codegen.CodegenConstants.*;
-import static org.openapitools.codegen.languages.KotlinServerCodegen.Constants.INTERFACE_ONLY;
-import static org.openapitools.codegen.languages.KotlinServerCodegen.Constants.RETURN_RESPONSE;
 
 @SuppressWarnings("static-method")
 public class KotlinClientCodegenModelTest {
@@ -534,7 +530,7 @@ private void givenSchemaObjectPropertyNameContainsDollarSignWhenGenerateThenDoll
     }
 
     @Test(description = "generate polymorphic kotlinx_serialization model")
-    public void polymorphicKotlinxSerialzation() throws IOException {
+    public void polymorphicKotlinxSerialization() throws IOException {
         File output = Files.createTempDirectory("test").toFile();
         output.deleteOnExit();
 
@@ -573,6 +569,54 @@ public void polymorphicKotlinxSerialzation() throws IOException {
         TestUtils.assertFileContains(birdKt, "@SerialName(value = \"BIRD\")");
     }
 
+    @Test(description = "generate polymorphic jackson model")
+    public void polymorphicJacksonSerialization() throws IOException {
+        File output = Files.createTempDirectory("test").toFile();
+//        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName("kotlin")
+                .setLibrary("jvm-okhttp4")
+                .setAdditionalProperties(new HashMap<>() {{
+                    put(CodegenConstants.SERIALIZATION_LIBRARY, "jackson");
+                    put(CodegenConstants.MODEL_PACKAGE, "xyz.abcdef.model");
+                }})
+                .setInputSpec("src/test/resources/3_0/kotlin/polymorphism.yaml")
+                .setOutputDir(output.getAbsolutePath().replace("\\", "/"));
+
+        final ClientOptInput clientOptInput = configurator.toClientOptInput();
+        DefaultGenerator generator = new DefaultGenerator();
+        List<File> files = generator.opts(clientOptInput).generate();
+
+        Assert.assertEquals(files.size(), 28);
+
+        final Path animalKt = Paths.get(output + "/src/main/kotlin/xyz/abcdef/model/Animal.kt");
+        // base has extra jackson imports
+        TestUtils.assertFileContains(animalKt, "import com.fasterxml.jackson.annotation.JsonIgnoreProperties");
+        TestUtils.assertFileContains(animalKt, "import com.fasterxml.jackson.annotation.JsonSubTypes");
+        TestUtils.assertFileContains(animalKt, "import com.fasterxml.jackson.annotation.JsonTypeInfo");
+        // and these are being used
+        TestUtils.assertFileContains(animalKt, "@JsonIgnoreProperties");
+        TestUtils.assertFileContains(animalKt, "@JsonSubTypes");
+        TestUtils.assertFileContains(animalKt, "@JsonTypeInfo");
+        // base is interface
+        TestUtils.assertFileContains(animalKt, "interface Animal");
+        // base properties are present
+        TestUtils.assertFileContains(animalKt, "val id");
+        TestUtils.assertFileContains(animalKt, "val optionalProperty");
+        // base doesn't contain discriminator
+        TestUtils.assertFileNotContains(animalKt, "val discriminator");
+
+        final Path birdKt = Paths.get(output + "/src/main/kotlin/xyz/abcdef/model/Bird.kt");
+        // derived has serial name set to mapping key
+        TestUtils.assertFileContains(birdKt, "data class Bird");
+        // derived properties are overridden
+        TestUtils.assertFileContains(birdKt, "override val id");
+        TestUtils.assertFileContains(birdKt, "override val optionalProperty");
+        // derived doesn't contain disciminator
+        TestUtils.assertFileNotContains(birdKt, "val discriminator");
+    }
+
     private static class ModelNameTest {
         private final String expectedName;
         private final String expectedClassName;

modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinSpringServerCodegenTest.java

@@ -60,4 +60,45 @@ public void gradleWrapperIsGenerated() throws IOException {
         //Different because file is not a text file
         assertTrue(Files.exists(gradleWrapperJarCloud));
     }
+
+    @Test(description = "generate polymorphic jackson model")
+    public void polymorphicJacksonSerialization() throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        KotlinSpringServerCodegen codegen = new KotlinSpringServerCodegen() ;
+        codegen.setOutputDir(output.getAbsolutePath());
+
+        new DefaultGenerator().opts(
+                new ClientOptInput()
+                        .openAPI(TestUtils.parseSpec("src/test/resources/3_0/kotlin/polymorphism.yaml"))
+                        .config(codegen)
+        ).generate();
+
+        final Path animalKt = Paths.get(output + "/src/main/kotlin/org/openapitools/model/Animal.kt");
+        // base has extra jackson imports
+        TestUtils.assertFileContains(animalKt, "import com.fasterxml.jackson.annotation.JsonIgnoreProperties");
+        TestUtils.assertFileContains(animalKt, "import com.fasterxml.jackson.annotation.JsonSubTypes");
+        TestUtils.assertFileContains(animalKt, "import com.fasterxml.jackson.annotation.JsonTypeInfo");
+        // and these are being used
+        TestUtils.assertFileContains(animalKt, "@JsonIgnoreProperties");
+        TestUtils.assertFileContains(animalKt, "@JsonSubTypes");
+        TestUtils.assertFileContains(animalKt, "@JsonTypeInfo");
+        // base is interface
+        TestUtils.assertFileContains(animalKt, "interface Animal");
+        // base properties are present
+        TestUtils.assertFileContains(animalKt, "val id");
+        TestUtils.assertFileContains(animalKt, "val optionalProperty");
+        // base doesn't contain discriminator
+        TestUtils.assertFileNotContains(animalKt, "val discriminator");
+
+        final Path birdKt = Paths.get(output + "/src/main/kotlin/org/openapitools/model/Bird.kt");
+        // derived has serial name set to mapping key
+        TestUtils.assertFileContains(birdKt, "data class Bird");
+        // derived properties are overridden
+        TestUtils.assertFileContains(birdKt, "override val id");
+        TestUtils.assertFileContains(birdKt, "override val optionalProperty");
+        // derived doesn't contain disciminator
+        TestUtils.assertFileNotContains(birdKt, "val discriminator");
+    }
 }

samples/server/petstore/kotlin-springboot-request-cookie/src/main/kotlin/org/openapitools/model/Animal.kt

@@ -1,6 +1,7 @@
 package org.openapitools.model
 
 import java.util.Objects
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties
 import com.fasterxml.jackson.annotation.JsonProperty
 import com.fasterxml.jackson.annotation.JsonSubTypes
 import com.fasterxml.jackson.annotation.JsonTypeInfo
@@ -20,7 +21,10 @@ import io.swagger.v3.oas.annotations.media.Schema
  * @param className 
  * @param color 
  */
-
+@JsonIgnoreProperties(
+  value = ["className"], // ignore manually set className, it will be automatically generated by Jackson during serialization
+  allowSetters = true // allows the className to be set during deserialization
+)
 @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "className", visible = true)
 @JsonSubTypes(
       JsonSubTypes.Type(value = Cat::class, name = "CAT"),