@objectstack/plugin-msw

MSW (Mock Service Worker) Plugin for ObjectStack Runtime. This plugin enables seamless integration with Mock Service Worker for testing and development environments.

🤖 AI Development Context

Role: Test Mocking Adapter Usage:

• Intercepts network requests in tests (Browser/Node).
• Simulates a real ObjectStack backend.

Plugin Capabilities

This plugin implements the ObjectStack plugin capability protocol:

• Protocol: com.objectstack.protocol.testing.mock.v1 (full conformance)
• Protocol: com.objectstack.protocol.api.rest.v1 (full conformance)
• Provides: ObjectStackServer interface for mock API operations
• Requires: com.objectstack.engine.objectql for data operations

See objectstack.config.ts for the complete capability manifest.

Features

• 🎯 Unified Dispatcher: Uses @objectstack/runtime's HttpDispatcher to ensure mocks behave exactly like the real server.
• 🔄 Full Protocol Support: Mocks all Runtime endpoints:
  • Auth (/auth)
  • Metadata (/metadata)
  • Data (/data - with filtering, batching, relations)
  • Storage (/storage)
  • Analytics (/analytics)
  • Automation (/automation)
• 🌐 Universal Support: Works in Browser (Service Worker) and Node.js (Interceptor).
• 🎨 Custom Handlers: Easily inject custom MSW handlers that take precedence.
• 📝 TypeScript First: Fully typed configuration.

Installation

pnpm add @objectstack/plugin-msw msw

Usage

With ObjectStack Runtime

import { MSWPlugin } from '@objectstack/plugin-msw';
import { ObjectKernel } from '@objectstack/runtime';

const kernel = new ObjectKernel();

// The MSW Plugin will initialize the HttpDispatcher and intercept requests
kernel.use(new MSWPlugin({
  enableBrowser: true,
  baseUrl: '/api/v1',
  logRequests: true
}));

await kernel.start();

Architecture

The plugin uses the HttpDispatcher from the Runtime to process requests intercepted by MSW. This means your mock server runs the actual ObjectStack business logic (permissions, validation, flow execution) in-memory, providing a high-fidelity simulation of the backend. }));

await kernel.bootstrap();

### Standalone Usage (Browser)

```typescript
import { setupWorker } from 'msw/browser';
import { http, HttpResponse } from 'msw';
import { ObjectStackServer } from '@objectstack/plugin-msw';

// 1. Initialize the mock server
ObjectStackServer.init(protocol);

// 2. Define your handlers
const handlers = [
  // Intercept GET /api/user/:id
  http.get('/api/user/:id', async ({ params }) => {
    const result = await ObjectStackServer.getData('user', params.id as string);
    return HttpResponse.json(result.data, { status: result.status });
  }),

  // Intercept POST /api/user
  http.post('/api/user', async ({ request }) => {
    const body = await request.json();
    const result = await ObjectStackServer.createData('user', body);
    return HttpResponse.json(result.data, { status: result.status });
  }),
];

// 3. Create and start the worker
const worker = setupWorker(...handlers);
await worker.start();

With Custom Handlers

import { MSWPlugin } from '@objectstack/plugin-msw';
import { http, HttpResponse } from 'msw';

const customHandlers = [
  http.get('/api/custom/:id', ({ params }) => {
    return HttpResponse.json({ id: params.id, custom: true });
  })
];

const plugin = new MSWPlugin({
  customHandlers,
  baseUrl: '/api/v1'
});

API Reference

MSWPlugin

The main plugin class that implements the ObjectStack Runtime Plugin interface.

Options

interface MSWPluginOptions {
  /**
   * Enable MSW in the browser environment
   * @default true
   */
  enableBrowser?: boolean;
  
  /**
   * Custom handlers to add to MSW
   */
  customHandlers?: Array<any>;
  
  /**
   * Base URL for API endpoints
   * @default '/api/v1'
   */
  baseUrl?: string;
  
  /**
   * Whether to log requests
   * @default true
   */
  logRequests?: boolean;
}

ObjectStackServer

The mock server that handles ObjectStack API calls.

Static Methods

• init(protocol, logger?) - Initialize the mock server with an ObjectStack protocol instance
• findData(object, params?) - Find records for an object
• getData(object, id) - Get a single record by ID
• createData(object, data) - Create a new record
• updateData(object, id, data) - Update an existing record
• deleteData(object, id) - Delete a record
• getUser(id) - Legacy method for getting user (alias for getData('user', id))
• createUser(data) - Legacy method for creating user (alias for createData('user', data))

Mocked Endpoints

The plugin automatically mocks the following ObjectStack API endpoints:

Discovery

• GET /api/v1 - Get API discovery information

Metadata

• GET /api/v1/meta - Get available metadata types
• GET /api/v1/meta/:type - Get metadata items for a type
• GET /api/v1/meta/:type/:name - Get specific metadata item

Data Operations

• GET /api/v1/data/:object - Find records
• GET /api/v1/data/:object/:id - Get record by ID
• POST /api/v1/data/:object - Create record
• PATCH /api/v1/data/:object/:id - Update record
• DELETE /api/v1/data/:object/:id - Delete record

UI Protocol

• GET /api/v1/ui/view/:object - Get UI view configuration

Example: Testing with Vitest

import { describe, it, expect, beforeAll, afterAll } from 'vitest';
import { setupWorker } from 'msw/browser';
import { ObjectStackServer } from '@objectstack/plugin-msw';
import { http, HttpResponse } from 'msw';

describe('User API', () => {
  let worker: any;

  beforeAll(async () => {
    // Initialize mock server
    ObjectStackServer.init(protocol);

    // Setup handlers
    const handlers = [
      http.get('/api/user/:id', async ({ params }) => {
        const result = await ObjectStackServer.getData('user', params.id as string);
        return HttpResponse.json(result.data, { status: result.status });
      })
    ];

    worker = setupWorker(...handlers);
    await worker.start({ onUnhandledRequest: 'bypass' });
  });

  afterAll(() => {
    worker.stop();
  });

  it('should get user by id', async () => {
    const response = await fetch('/api/user/123');
    const data = await response.json();
    
    expect(response.status).toBe(200);
    expect(data).toBeDefined();
  });
});

License

Apache-2.0

Related Packages

• @objectstack/runtime - ObjectStack Runtime
• @objectstack/spec - ObjectStack Specifications
• msw - Mock Service Worker