A utility library for simplifying the mocking of @orpc/contract procedures (specifically for OpenAPI-based orpc contracts) using Mock Service Worker (MSW) for testing. This library is currently designed for OpenAPI orpc and does not support orpc's RPCHandler.

• Seamless Integration: Works directly with @orpc/contract for type-safe API definitions.
• MSW Powered: Leverages Mock Service Worker for powerful request interception and mocking capabilities.
• Simplified Mocking: Streamlines the creation of mock handlers for orpc procedures.
• Type-Safe Responses: Ensures mock responses adhere to your defined orpc contract types.
• Flexible Response Handling: Supports dynamic responses and custom HttpResponse or Response objects.

• Node.js (v22 or later recommended)
• pnpm (v10 or later recommended)

Install orpc-msw and its peer dependencies:

pnpm add -D orpc-msw @orpc/contract @orpc/openapi-client msw

Here's a quick example of how to use orpc-msw to mock an orpc procedure:

First, define your orpc contract:

// contract.ts
import { os } from "@orpc/server";
import { z } from "zod";

export const myContract = os.router({
  greeter: os
    .route({ method: "GET", path: "/hello" })
    .input(z.object({ name: z.string() }))
    .output(z.object({ message: z.string() })),
});

Then, create your MSW handlers using createMSWUtilities:

// msw-handlers.ts
import { setupWorker } from "msw/browser";
import { createMSWUtilities } from "orpc-msw";
import { myContract } from "./contract";

const msw = createMSWUtilities({
  router: myContract,
  baseUrl: "http://localhost:3000", // Your API base URL
});

export const handlers = [
  msw.greeter.handler(({ input }) => ({
    message: `Hello, ${input.name}! This is a mock response.`,
  })),
];

// In your setup file (e.g., src/mocks/browser.ts for browser environments)
export const worker = setupWorker(...handlers);

Start the worker in your application:

// main.ts or test-setup.ts
import { worker } from "./msw-handlers";

if (import.meta.env.DEV) {
  worker.start();
}

For more detailed information, guides, and API reference, please visit the documentation website.

This project is licensed under the MIT License.