Testing

@bunito/testing provides a shared Test context plus small helpers for Bun test suites. Feature packages can register their own test factories on that context, so tests can swap runtime integrations for deterministic in-memory modules.

Test Context

Import Test from @bunito/testing in test files:

import { describe, expect, test } from 'bun:test';
import { App } from '@bunito/bunito';
import { Test } from '@bunito/testing';

describe('feature', () => {
  test('uses test modules', async () => {
    const app = await App.start({
      imports: [Test.ConfigModule, Test.LoggerModule, AppModule],
    });

    await app.shutdown();
  });
});

Factories are registered lazily by importing the feature package that owns them. For example, importing @bunito/bun, @bunito/config, @bunito/logger, or @bunito/broker makes that package's Test.* helpers available.

Core Helpers

@bunito/testing exports:

• Test: the shared context used by package and example tests.
• defineTestFactory(): registers a lazy value on Test.
• mockClass(): creates a Bun-mocked object from a class prototype.
• spyOnObject(): spies on methods from an object prototype chain.
• TestException: an exception type for testing helpers.

Use defineTestFactory() when a reusable test value should be created only when a test first reads it:

import type { MockedObject } from '@bunito/testing';
import { Test, defineTestFactory, mockClass } from '@bunito/testing';

class Mailer {
  send(): void {}
}

declare global {
  namespace Bunito {
    interface Test {
      mailer: MockedObject<Mailer>;
    }
  }
}

defineTestFactory('mailer', () => mockClass(Mailer));

expect(Test.mailer.send).not.toBeCalled();

Feature Test Modules

Several feature packages register ready-to-use modules:

• @bunito/config: Test.ConfigModule, Test.configService, and Test.defineConfig.
• @bunito/logger: Test.LoggerModule and Test.getLogger.
• @bunito/bun: Test.BunServerModule, Test.bunServerFactory, Test.bunServer, Test.BunSecretsModule, and Test.bunSecretsService.
• @bunito/broker: Test.BrokerModule and Test.broker.

These modules are normal module options. Put them before the runtime module they replace when another feature imports that runtime module automatically:

import '@bunito/bun';

import { App } from '@bunito/bunito';
import { HTTPModule } from '@bunito/http';
import { Test } from '@bunito/testing';

const app = await App.start({
  imports: [Test.BunServerModule, Test.LoggerModule, HTTPModule, AppModule],
});

const response = await Test.bunServer
  .buildRequest('/health')
  .withMethod('GET')
  .send();

expect(response.status).toBe(200);

await app.shutdown();

Coverage

Package-local src/testing/** helpers are intended to support other tests. They are ignored by coverage and do not need dedicated sibling test files.

Continue with Configuration and Logging for configuration and logger test modules.