Create versions.mdx based on issue #267

Author: kgowru

fern/products/sdks/overview/typescript/versions.mdx

@@ -0,0 +1,95 @@
+---
+title: "Integration Tests"
+description: "Automatically generate integration tests for your TypeScript SDK"
+---
+
+## Overview
+
+Integration tests are automatically generated when using version 1.2.4 or later of the TypeScript SDK generator. These tests validate your SDK's functionality by testing it against a mock server that implements your API specification.
+
+<Note>
+Integration tests are currently supported for TypeScript and C# SDKs. Support for other languages is in development.
+</Note>
+
+## Requirements
+
+- Fern CLI version that supports SDK generator version 1.2.4 or later
+- TypeScript SDK generator version 1.2.4 or later (recommended: 1.5.0+)
+
+## Updating Your Generator Version
+
+To use integration tests, ensure you're using a recent version of the TypeScript SDK generator:
+
+```yaml
+generators:
+  - name: fernapi/fern-typescript-sdk
+    version: 1.5.0
+    output:
+      location: local-file-system
+      path: ../generated
+```
+
+If you previously generated an SDK with an older version, you may need to update your Fern CLI:
+
+```bash
+npm install -g fern-api
+```
+
+## Generated Tests Structure
+
+When you generate your SDK, Fern automatically creates integration tests in the `__test__` directory. These tests include:
+
+- Base unit tests for core functionality
+- Integration tests that validate your API endpoints
+- A mock server implementation matching your API specification
+
+## Running Integration Tests
+
+1. Navigate to your generated SDK directory
+2. Install dependencies:
+```bash
+npm install
+```
+
+3. Run the test suite:
+```bash
+npm test
+```
+
+## Custom Tests
+
+While Fern generates comprehensive integration tests automatically, you can add custom tests to cover specific use cases:
+
+1. Create a new test file in the `__test__` directory
+2. Import your SDK client
+3. Write tests using your preferred testing framework (Jest is included by default)
+
+Example custom test:
+
+```typescript
+import { YourApiClient } from "../src";
+
+describe("Custom API Tests", () => {
+  const client = new YourApiClient({
+    environment: "http://localhost:8080",
+  });
+
+  test("custom endpoint behavior", async () => {
+    const response = await client.yourEndpoint();
+    expect(response).toBeDefined();
+  });
+});
+```
+
+## Troubleshooting
+
+If you encounter issues with integration tests:
+
+- Verify you're using TypeScript SDK generator version 1.2.4 or later
+- Ensure your Fern CLI is up to date
+- Check that your API specification is valid and complete
+- Review the mock server implementation for any configuration issues
+
+<Note>
+The mock server uses your API specification to simulate responses. Ensure your specification accurately reflects your API's behavior for reliable test results.
+</Note>