add tests

Author: mdjastrzebski

packages/core/src/ai/__folder__/vercel.test.ts

@@ -0,0 +1,63 @@
+import { expect, test } from 'vitest';
+import { createMockVercelModel } from '../../mock/vercel-mock-model.js';
+import { createApp } from '../../application.js';
+import { Message } from '../../domain.js';
+import { VercelChatModelAdapter } from '../vercel.js';
+
+const messages: Message[] = [{ role: 'user', content: 'Hello' }];
+
+test('sends system messages when system prompt is provided', async () => {
+  const { languageModel, calls } = createMockVercelModel({ text: 'Hello, world!' });
+  const app = createApp({
+    chatModel: new VercelChatModelAdapter({ languageModel }),
+    systemPrompt: 'This is system prompt',
+  });
+
+  await app.processMessages(messages);
+  expect(calls.length).toBe(1);
+  expect(calls[0].prompt).toContainEqual({
+    role: 'system',
+    content: 'This is system prompt',
+  });
+});
+
+test('does not send system message when system prompt is not provided', async () => {
+  const { languageModel, calls } = createMockVercelModel({ text: 'Hello, world!' });
+  const app = createApp({
+    chatModel: new VercelChatModelAdapter({ languageModel }),
+  });
+
+  await app.processMessages(messages);
+  expect(calls.length).toBe(1);
+  expect(calls[0].prompt).not.toContainEqual({
+    role: 'system',
+  });
+});
+
+test('does not send system message when system prompt returns null', async () => {
+  const { languageModel, calls } = createMockVercelModel({ text: 'Hello, world!' });
+  const app = createApp({
+    chatModel: new VercelChatModelAdapter({ languageModel }),
+    systemPrompt: () => null,
+  });
+
+  await app.processMessages(messages);
+  expect(calls.length).toBe(1);
+  expect(calls[0].prompt).not.toContainEqual({
+    role: 'system',
+  });
+});
+
+test('does not send system message when system prompt returns empty string', async () => {
+  const { languageModel, calls } = createMockVercelModel({ text: 'Hello, world!' });
+  const app = createApp({
+    chatModel: new VercelChatModelAdapter({ languageModel }),
+    systemPrompt: () => '',
+  });
+
+  await app.processMessages(messages);
+  expect(calls.length).toBe(1);
+  expect(calls[0].prompt).not.toContainEqual({
+    role: 'system',
+  });
+});

packages/core/src/mock/vercel-mock-model.ts

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+import { LanguageModelV1CallOptions } from 'ai';
+import { MockLanguageModelV1 } from 'ai/test';
+
+export type MockVercelModelOptions = {
+  text: string;
+};
+
+export function createMockVercelModel({ text }: MockVercelModelOptions) {
+  const calls: LanguageModelV1CallOptions[] = [];
+  const languageModel = new MockLanguageModelV1({
+    doGenerate: (options) => {
+      calls.push(options);
+      return Promise.resolve({
+        rawCall: { rawPrompt: null, rawSettings: {} },
+        finishReason: 'stop',
+        usage: { promptTokens: 10, completionTokens: 20 },
+        text,
+      });
+    },
+    // TODO: add doStream when needed
+  });
+
+  return { languageModel, calls };
+}