@dunx/testing

Test a dunx app against its real container and a real Bun.serve. Replace the bindings you want to fake, and everything else runs as it does in production. Starting a server on port 0 takes about a millisecond, so there is no mock request object and no in-memory transport.

Usage

import { provide } from '@dunx/core';
import { createTestApp, createTestServer } from '@dunx/testing';

// The container only.
const app = await createTestApp({
  modules: [UsersModule],
  overrides: [provide(Clock, { useValue: new FixedClock('2026-01-01') })],
});
expect(app.get(UsersService).today()).toBe('2026-01-01');
await app.shutdown();

// The container behind a real server.
const server = await createTestServer({
  modules: [ApiModule],
  overrides: [provide(Storage, { useClass: MemoryStorage })],
  prefix: 'api',
});
const { status, body } = await server.json<User[]>('api/users');
await server.close();

What is here

The Testing guide covers each of these in full.

Export	What it does
`createTestApp`	Boots the container, with your overrides applied first
`createTestServer`, `TestServer`	The same, behind a real `Bun.serve` on port 0
`testClient`, `TestClient`	`fetch` against a base URL, plus a JSON helper
`http2Client`, `Http2Client`	The same over HTTP/2, for a server started with `http2: true`
`RecordingLogger`	A `Logger` that keeps every entry, so a test can assert on what it logged
`testRoot`	The root module `createTestApp` boots, for calling `HttpFactory.create` yourself

Notes

An override replaces a binding in every module that binds it, so a test that fakes Logger does not need to know how many modules bind one. Overriding a token that nothing binds is an error. Overriding a class that nothing asks for is allowed and does nothing.
Overrides are applied before anything is created, so the provider you replaced never runs: its useFactory is not called and its onInit does not fire. You can override a database without it connecting.
Request logging and boot logging are off unless you turn them on.
The health module's shutdown drain is set to drainDelayMs: 0, since a test has no load balancer waiting on it. An override of ReadinessOptions you pass yourself takes precedence.
HttpOptions you do not pass are left unset; nothing is copied from production. Pass the same middleware and onError that main.ts passes, or the test server will not behave like your app. createTestServer warns when it finds guards in the graph that no middleware list attaches.