tests: Implement MockLLMProvider for tier 2 integration tests

packages/llm/tests/mock.test.ts

@@ -0,0 +1,63 @@
+import { describe, test, expect } from "vitest";
+import { z } from "zod";
+import { MockLLMProvider } from "../src/providers/mock.js";
+
+describe("MockLLMProvider Unit Tests (Tier 1)", () => {
+  test("returns parsed matching data for valid mock response", async () => {
+    const TestSchema = z.object({
+      name: z.string(),
+      age: z.number(),
+    });
+
+    const mockData = { name: "Alice", age: 30 };
+    const provider = new MockLLMProvider([mockData]);
+
+    const response = await provider.generateStructuredResponse({
+      systemPrompt: "system prompt",
+      userContext: "user context",
+      schema: TestSchema,
+    });
+
+    expect(response.success).toBe(true);
+    expect(response.data).toEqual(mockData);
+  });
+
+  test("returns failure for malformed mock response", async () => {
+    const TestSchema = z.object({
+      name: z.string(),
+      age: z.number(),
+    });
+
+    // age is a string instead of a number, which violates schema
+    const malformedData = { name: "Alice", age: "thirty" };
+    const provider = new MockLLMProvider([malformedData]);
+
+    const response = await provider.generateStructuredResponse({
+      systemPrompt: "system prompt",
+      userContext: "user context",
+      schema: TestSchema,
+    });
+
+    expect(response.success).toBe(false);
+    expect(response.error).toBeDefined();
+    expect(response.data).toBeUndefined();
+  });
+
+  test("returns failure when mock responses are exhausted", async () => {
+    const TestSchema = z.object({
+      name: z.string(),
+    });
+
+    const provider = new MockLLMProvider([]);
+
+    const response = await provider.generateStructuredResponse({
+      systemPrompt: "system prompt",
+      userContext: "user context",
+      schema: TestSchema,
+    });
+
+    expect(response.success).toBe(false);
+    expect(response.error).toBe("Mock responses exhausted");
+    expect(response.data).toBeUndefined();
+  });
+});