feat: return function when registering

[KATT]

Closes #24

Why

When testing RPC function it's useful to be able to call them directly with the implementation

Example

// retool.ts

// [...]

const rpc = new RetoolRPC({
  // [...]
});

export const helloWorld = rpc.register({
  name: 'helloWorld',
  arguments: {
    name: { type: 'string', description: 'Your name', required: true },
  },
  implementation: async (args, context) => {
    return {
      message: `Hello ${args.name}`,
      context,
    };
  },
});

// retool.test.ts
import { helloWorld } from './retool';

test('helloWorld', async () => {
  const result = await helloWorld(
    {
      name: 'world',
    },
    {
      // ... context
    },
  );
  expect(result.message).toBe(`Hello world`);
});

What this does

• Adds the ability to infer the return type of the registered function
• Returns the function so it can be called directly

Alternatives / workarounds

It's possible to work around, but it's a bit annoying, it's nicer if the SDK could just return the function implementation

[huytool157]

Change is live on 0.1.5