feat: Adding Vercel AI SDK mapper (#895)

Author: abarker-launchdarkly

packages/sdk/server-ai/__tests__/LDAIClientImpl.test.ts

@@ -57,6 +57,7 @@ it('returns config with interpolated messagess', async () => {
     ],
     tracker: expect.any(Object),
     enabled: true,
+    toVercelAISDK: expect.any(Function),
   });
 });
 
@@ -102,6 +103,7 @@ it('handles missing metadata in variation', async () => {
     messages: [{ role: 'system', content: 'Hello' }],
     tracker: expect.any(Object),
     enabled: false,
+    toVercelAISDK: expect.any(Function),
   });
 });
 
@@ -125,6 +127,7 @@ it('passes the default value to the underlying client', async () => {
     provider: defaultValue.provider,
     tracker: expect.any(Object),
     enabled: false,
+    toVercelAISDK: expect.any(Function),
   });
 
   expect(mockLdClient.variation).toHaveBeenCalledWith(key, testContext, defaultValue);

packages/sdk/server-ai/__tests__/LDAIConfigMapper.test.ts

@@ -0,0 +1,159 @@
+import { LDMessage, VercelAISDKMapOptions } from '../src/api/config';
+import { LDAIConfigMapper } from '../src/LDAIConfigMapper';
+
+describe('_findParameter', () => {
+  it('handles undefined model and messages', () => {
+    const mapper = new LDAIConfigMapper();
+    // eslint-disable-next-line @typescript-eslint/dot-notation
+    expect(mapper['_findParameter']<number>('test-param')).toBeUndefined();
+  });
+
+  it('handles parameter not found', () => {
+    const mapper = new LDAIConfigMapper({
+      name: 'test-ai-model',
+      parameters: {
+        'test-param': 123,
+      },
+      custom: {
+        'test-param': 456,
+      },
+    });
+    // eslint-disable-next-line @typescript-eslint/dot-notation
+    expect(mapper['_findParameter']<number>('other-param')).toBeUndefined();
+  });
+
+  it('finds parameter from single model parameter', () => {
+    const mapper = new LDAIConfigMapper({
+      name: 'test-ai-model',
+      parameters: {
+        'test-param': 123,
+      },
+    });
+    // eslint-disable-next-line @typescript-eslint/dot-notation
+    expect(mapper['_findParameter']<number>('test-param')).toEqual(123);
+  });
+
+  it('finds parameter from multiple model parameters', () => {
+    const mapper = new LDAIConfigMapper({
+      name: 'test-ai-model',
+      parameters: {
+        testParam: 123,
+      },
+    });
+    // eslint-disable-next-line @typescript-eslint/dot-notation
+    expect(mapper['_findParameter']<number>('test-param', 'testParam')).toEqual(123);
+  });
+
+  it('finds parameter from single model custom parameter', () => {
+    const mapper = new LDAIConfigMapper({
+      name: 'test-ai-model',
+      custom: {
+        'test-param': 123,
+      },
+    });
+    // eslint-disable-next-line @typescript-eslint/dot-notation
+    expect(mapper['_findParameter']<number>('test-param')).toEqual(123);
+  });
+
+  it('finds parameter from multiple model custom parameters', () => {
+    const mapper = new LDAIConfigMapper({
+      name: 'test-ai-model',
+      custom: {
+        testParam: 123,
+      },
+    });
+    // eslint-disable-next-line @typescript-eslint/dot-notation
+    expect(mapper['_findParameter']<number>('test-param', 'testParam')).toEqual(123);
+  });
+
+  it('gives precedence to model parameters over model custom parameters', () => {
+    const mapper = new LDAIConfigMapper({
+      name: 'test-ai-model',
+      parameters: {
+        'test-param': 123,
+      },
+      custom: {
+        'test-param': 456,
+      },
+    });
+    // eslint-disable-next-line @typescript-eslint/dot-notation
+    expect(mapper['_findParameter']<number>('test-param', 'testParam')).toEqual(123);
+  });
+});
+
+describe('toVercelAIAISDK', () => {
+  const mockModel = { name: 'mockModel' };
+  const mockMessages: LDMessage[] = [
+    { role: 'user', content: 'test prompt' },
+    { role: 'system', content: 'test instruction' },
+  ];
+  const mockOptions: VercelAISDKMapOptions = {
+    nonInterpolatedMessages: [{ role: 'assistant', content: 'test assistant instruction' }],
+  };
+  const mockProvider = jest.fn().mockReturnValue(mockModel);
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('handles undefined model and messages', () => {
+    const mapper = new LDAIConfigMapper();
+    const result = mapper.toVercelAISDK(mockProvider);
+
+    expect(mockProvider).toHaveBeenCalledWith('');
+    expect(result).toEqual(
+      expect.objectContaining({
+        model: mockModel,
+        messages: undefined,
+      }),
+    );
+  });
+
+  it('uses additional messages', () => {
+    const mapper = new LDAIConfigMapper({ name: 'test-ai-model' });
+    const result = mapper.toVercelAISDK(mockProvider, mockOptions);
+
+    expect(mockProvider).toHaveBeenCalledWith('test-ai-model');
+    expect(result).toEqual(
+      expect.objectContaining({
+        model: mockModel,
+        messages: mockOptions.nonInterpolatedMessages,
+      }),
+    );
+  });
+
+  it('combines config messages and additional messages', () => {
+    const mapper = new LDAIConfigMapper({ name: 'test-ai-model' }, undefined, mockMessages);
+    const result = mapper.toVercelAISDK(mockProvider, mockOptions);
+
+    expect(mockProvider).toHaveBeenCalledWith('test-ai-model');
+    expect(result).toEqual(
+      expect.objectContaining({
+        model: mockModel,
+        messages: [...mockMessages, ...(mockOptions.nonInterpolatedMessages ?? [])],
+      }),
+    );
+  });
+
+  it('requests parameters correctly', () => {
+    const mapper = new LDAIConfigMapper({ name: 'test-ai-model' }, undefined, mockMessages);
+    const findParameterMock = jest.spyOn(mapper as any, '_findParameter');
+    const result = mapper.toVercelAISDK(mockProvider);
+
+    expect(mockProvider).toHaveBeenCalledWith('test-ai-model');
+    expect(result).toEqual(
+      expect.objectContaining({
+        model: mockModel,
+        messages: mockMessages,
+      }),
+    );
+    expect(findParameterMock).toHaveBeenCalledWith('max_tokens', 'maxTokens');
+    expect(findParameterMock).toHaveBeenCalledWith('temperature');
+    expect(findParameterMock).toHaveBeenCalledWith('top_p', 'topP');
+    expect(findParameterMock).toHaveBeenCalledWith('top_k', 'topK');
+    expect(findParameterMock).toHaveBeenCalledWith('presence_penalty', 'presencePenalty');
+    expect(findParameterMock).toHaveBeenCalledWith('frequency_penalty', 'frequencyPenalty');
+    expect(findParameterMock).toHaveBeenCalledWith('stop', 'stop_sequences', 'stopSequences');
+    expect(findParameterMock).toHaveBeenCalledWith('seed');
+  });
+});