diff --git a/examples/csharp-generate-serializer/__snapshots__/index.spec.ts.snap b/examples/csharp-generate-serializer/__snapshots__/index.spec.ts.snap
index d7b192d70d..9a9502ef4c 100644
--- a/examples/csharp-generate-serializer/__snapshots__/index.spec.ts.snap
+++ b/examples/csharp-generate-serializer/__snapshots__/index.spec.ts.snap
@@ -62,7 +62,7 @@ internal class RootConverter : JsonConverter<Root>
   {
     if (value == null)
     {
-      JsonSerializer.Serialize(writer, null);
+      JsonSerializer.Serialize(writer, null, options);
       return;
     }
     var properties = value.GetType().GetProperties();
@@ -72,7 +72,7 @@ internal class RootConverter : JsonConverter<Root>
     if(value.Email != null) { 
       // write property name and let the serializer serialize the value itself
       writer.WritePropertyName(\\"email\\");
-      JsonSerializer.Serialize(writer, value.Email);
+      JsonSerializer.Serialize(writer, value.Email, options);
     }
 
 
diff --git a/src/generators/csharp/CSharpRenderer.ts b/src/generators/csharp/CSharpRenderer.ts
index 797d784eb1..0cbdc5730c 100644
--- a/src/generators/csharp/CSharpRenderer.ts
+++ b/src/generators/csharp/CSharpRenderer.ts
@@ -1,6 +1,6 @@
 import { AbstractRenderer } from '../AbstractRenderer';
 import { CSharpGenerator, CSharpOptions } from './CSharpGenerator';
-import { Preset, ConstrainedMetaModel, InputMetaModel } from '../../models';
+import { Preset, ConstrainedMetaModel, InputMetaModel, ConstrainedObjectPropertyModel } from '../../models';
 import { FormatHelpers } from '../../helpers/FormatHelpers';
 import { CSharpDependencyManager } from './CSharpDependencyManager';
 
@@ -27,4 +27,8 @@ export abstract class CSharpRenderer<
     lines = FormatHelpers.breakLines(lines);
     return lines.map((line) => `// ${line}`).join('\n');
   }
+
+  optionalMark(propertyModel: ConstrainedObjectPropertyModel): string {
+    return propertyModel.required ? '' : '?';
+  }
 }
diff --git a/test/generators/dart/DartFileGenerator.spec.ts b/test/generators/dart/DartFileGenerator.spec.ts
new file mode 100644
index 0000000000..5577f7678d
--- /dev/null
+++ b/test/generators/dart/DartFileGenerator.spec.ts
@@ -0,0 +1,51 @@
+import { CommonInputModel, CommonModel, FileHelpers, DartFileGenerator, OutputModel } from '../../../src';
+import * as path from 'path';
+
+describe('DartFileGenerator', () => {
+  afterEach(() => {
+    jest.restoreAllMocks();
+  });
+
+  describe('generateToFile()', () => {
+    const doc = {
+      $id: 'CustomClass',
+      type: 'object',
+      additionalProperties: true,
+      properties: {
+        someProp: { type: 'string' },
+        someEnum: {
+          $id: 'CustomEnum',
+          type: 'string',
+          enum: ['Texas', 'Alabama', 'California'],
+        }
+      }
+    };
+    test('should throw accurate error if file cannot be written', async () => {
+      const generator = new DartFileGenerator();
+      const expectedError = new Error('write error');
+      jest.spyOn(FileHelpers, 'writerToFileSystem').mockRejectedValue(expectedError);
+      jest.spyOn(generator, 'generateCompleteModels').mockResolvedValue([new OutputModel('content', new CommonModel(), '', new CommonInputModel(), [])]);
+    
+      await expect(generator.generateToFiles(doc, '/test/', {packageName: 'SomePackage'})).rejects.toEqual(expectedError);
+      expect(generator.generateCompleteModels).toHaveBeenCalledTimes(1);
+      expect(FileHelpers.writerToFileSystem).toHaveBeenCalledTimes(1);
+    });
+    test('should try and generate models to files', async () => {
+      const generator = new DartFileGenerator();
+      const outputDir = './test';
+      const expectedOutputDirPath = path.resolve(outputDir);
+      const expectedOutputFilePath = path.resolve(`${outputDir}/test.dart`);
+      const expectedWriteToFileParameters = [
+        'content',
+        expectedOutputFilePath,
+      ];
+      jest.spyOn(FileHelpers, 'writerToFileSystem').mockResolvedValue(undefined);
+      jest.spyOn(generator, 'generateCompleteModels').mockResolvedValue([new OutputModel('content', new CommonModel(), 'test', new CommonInputModel(), [])]);
+      
+      await generator.generateToFiles(doc, expectedOutputDirPath, {packageName: 'SomePackage'});
+      expect(generator.generateCompleteModels).toHaveBeenCalledTimes(1);
+      expect(FileHelpers.writerToFileSystem).toHaveBeenCalledTimes(1);
+      expect((FileHelpers.writerToFileSystem as jest.Mock).mock.calls[0]).toEqual(expectedWriteToFileParameters);
+    });
+  });
+});
diff --git a/test/generators/java/renderers/EnumRenderer.spec.ts b/test/generators/java/renderers/EnumRenderer.spec.ts
new file mode 100644
index 0000000000..8345b093c2
--- /dev/null
+++ b/test/generators/java/renderers/EnumRenderer.spec.ts
@@ -0,0 +1,21 @@
+import { JavaGenerator } from '../../../../src/generators';
+import { EnumRenderer } from '../../../../src/generators/java/renderers/EnumRenderer';
+import { CommonInputModel, CommonModel } from '../../../../src/models';
+
+describe('EnumRenderer', () => {
+  let renderer: EnumRenderer;
+  beforeEach(() => {
+    renderer = new EnumRenderer(JavaGenerator.defaultOptions, new JavaGenerator(), [], new CommonModel(), new CommonInputModel());
+  });
+
+  describe('normalizeKey()', () => {
+    test('should correctly format " " to correct key', () => {
+      const key = renderer.normalizeKey('something something');
+      expect(key).toEqual('SOMETHING_SOMETHING');
+    });
+    test('should correctly format "_" to correct key', () => {
+      const key = renderer.normalizeKey('something_something');
+      expect(key).toEqual('SOMETHING_SOMETHING');
+    });
+  });
+});