@setu-ts/testing — exercise applications and middleware

Add it: setu add testing adds a dev dependency; it registers no plugin and provides no capability.

Test the scaffold’s real composition

Pass the unstarted application from your config to this test helper:

import { createTestApp } from '@setu-ts/testing';
import type { IKernelApplication } from '@setu-ts/testing';

export async function checkGreeting(app: IKernelApplication): Promise<void> {
  const testApp = await createTestApp({ app });
  try {
    const response = await testApp.inject({ method: 'GET', url: '/greeting' });
    if (response.statusCode !== 200) throw new Error(response.body ?? 'Request failed');
  } finally {
    await testApp.stop();
  }
}

Test a middleware without starting an application

import type { MiddlewareFunction } from '@setu-ts/common';
import { createTestContext } from '@setu-ts/testing';

export async function checkMiddleware(middleware: MiddlewareFunction): Promise<void> {
  const ctx = createTestContext({ request: { method: 'GET', path: '/private' } });
  let continued = false;
  await middleware(ctx, async () => { continued = true; });
  if (continued) throw new Error('Expected middleware to refuse');
  if (ctx.response.snapshot().status !== 401) throw new Error('Expected 401');
}

Behaviour the types do not show

• autoStart defaults to true and starts without binding a socket. The plugins arm must include a runtime provider; no plugins are installed implicitly.
• createTestApp returns IKernelApplication; inject resolves statusCode, headers, body (string | null) and json<T>(). stop() stops plugin workers.
• Use autoStart: false to add global middleware or more plugins before starting.
• without checks every exact plugin name before removing anything; an unknown name throws.
• overrideCapability cannot undo the real provider’s registration side effects, and refuses missing or multi-provider capabilities during initialization.
• createMockPlugin provides a missing capability; alongside a real provider it causes a duplicate-provider startup error.

Other options

• createTestApp({ plugins }) builds an isolated composition instead of adopting app.
• overrideProvider replaces a DI provider; MockServiceRegistry and MockResponse are doubles.
• inject accepts a URL, request options or web request; collectStream reads streaming bodies.