Add tests

Author: maksimkurb

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

@@ -665,6 +665,85 @@ public void testJdkHttpClientWithJackson3() {
                 .contains("<groupId>com.fasterxml.jackson.core</groupId>");
     }
 
+    @Test
+    public void testJdkHttpClientWithJackson3AndOpenApiNullable() {
+        final Path output = newTempFolder();
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName(JAVA_GENERATOR)
+                .setLibrary(JavaClientCodegen.NATIVE)
+                .addAdditionalProperty(CodegenConstants.API_PACKAGE, "xyz.abcdef.api")
+                .addAdditionalProperty(CodegenConstants.INVOKER_PACKAGE, "xyz.abcdef.invoker")
+                .addAdditionalProperty(JavaClientCodegen.USE_JACKSON_3, true)
+                .addAdditionalProperty(JavaClientCodegen.OPENAPI_NULLABLE, true)
+                .setInputSpec("src/test/resources/3_0/ping.yaml")
+                .setOutputDir(output.toString().replace("\\", "/"));
+
+        List<File> files = new DefaultGenerator().opts(configurator.toClientOptInput()).generate();
+
+        validateJavaSourceFiles(files);
+        assertThat(output.resolve("src/main/java/xyz/abcdef/invoker/ApiClient.java")).content()
+                .contains("import org.openapitools.jackson.nullable.JsonNullableJackson3Module;")
+                .contains("new JsonNullableJackson3Module()")
+                .doesNotContain("JsonNullableModule");
+        assertThat(output.resolve("src/main/java/xyz/abcdef/invoker/JSON.java")).content()
+                .contains("import org.openapitools.jackson.nullable.JsonNullableJackson3Module;")
+                .contains("new JsonNullableJackson3Module()")
+                .doesNotContain("JsonNullableModule");
+        assertThat(output.resolve("pom.xml")).content()
+                .contains("jackson-databind-nullable");
+    }
+
+    @Test
+    public void testApacheHttpClientWithJackson3() {
+        final Path output = newTempFolder();
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName(JAVA_GENERATOR)
+                .setLibrary(JavaClientCodegen.APACHE)
+                .addAdditionalProperty(CodegenConstants.API_PACKAGE, "xyz.abcdef.api")
+                .addAdditionalProperty(CodegenConstants.INVOKER_PACKAGE, "xyz.abcdef.invoker")
+                .addAdditionalProperty(JavaClientCodegen.USE_JACKSON_3, true)
+                .addAdditionalProperty(JavaClientCodegen.OPENAPI_NULLABLE, true)
+                .setInputSpec("src/test/resources/3_0/ping.yaml")
+                .setOutputDir(output.toString().replace("\\", "/"));
+
+        List<File> files = new DefaultGenerator().opts(configurator.toClientOptInput()).generate();
+
+        validateJavaSourceFiles(files);
+        assertThat(output.resolve("src/main/java/xyz/abcdef/invoker/ApiClient.java")).content()
+                .contains("import tools.jackson.databind.*")
+                .contains("import tools.jackson.databind.json.JsonMapper;")
+                .contains("import org.openapitools.jackson.nullable.JsonNullableJackson3Module;")
+                .contains("new JsonNullableJackson3Module()")
+                .doesNotContain("import com.fasterxml.jackson.databind");
+        assertThat(output.resolve("src/main/java/xyz/abcdef/api/DefaultApi.java")).content()
+                .contains("import tools.jackson.core.type.TypeReference;")
+                .doesNotContain("import com.fasterxml.jackson.core.type.TypeReference");
+        assertThat(output.resolve("pom.xml")).content()
+                .contains("<groupId>tools.jackson.core</groupId>")
+                .contains("<groupId>com.fasterxml.jackson.core</groupId>")
+                .contains("jackson-databind-nullable");
+    }
+
+    @Test(dataProvider = "springBoot4Jackson3Libraries")
+    void supportsJackson3WithOpenApiNullableForSpringBoot4Libraries(String library) {
+        String outputDir = newTempFolder().toString();
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName(JAVA_GENERATOR)
+                .setLibrary(library)
+                .addAdditionalProperty(USE_JACKSON_3, true)
+                .addAdditionalProperty(USE_SPRING_BOOT4, true)
+                .addAdditionalProperty(OPENAPI_NULLABLE, true)
+                .setInputSpec("src/test/resources/3_0/java/autoset_constant.yaml")
+                .setOutputDir(outputDir);
+
+        List<File> files = new DefaultGenerator().opts(configurator.toClientOptInput()).generate();
+
+        assertThat(files).isNotEmpty();
+        assertThat(new File(outputDir, "src/main/java/org/openapitools/client/ApiClient.java"))
+                .content()
+                .contains("JsonNullableJackson3Module");
+    }
+
     @Test
     public void testReferencedHeader() {
         final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/issue855.yaml");