Testing Elpod Services and Elysia Routes

Elpod test utilities let Bun and Elysia applications replace providers while exercising real route composition. Use them when a service needs fast unit tests and the HTTP boundary needs integration tests with controlled dependencies.

The idea

Unit tests inspect one tool at a time. Application tests rehearse the whole scene: routes, validation, request scopes, plugins, errors, and cleanup. You want both kinds of rehearsal before launch.

How Elpod provides it

createTestApplication() boots the application in memory and exposes native Request/Response integration. It is useful for route tests that should exercise the same composition and error hooks as production.

import { afterEach, expect, test } from "bun:test";
import { createTestApplication } from "@elpod/core";
import { app } from "../src/app";

test("lists users", async () => {
  const testApp = await createTestApplication(app, {
    environment: "test",
    overrides: [fakeDatabaseProvider],
  });

  try {
    const response = await testApp.request("/users");
    expect(response.status).toBe(200);
  } finally {
    await testApp.dispose();
  }
});

request(path, init) creates a native Request; dispose() closes the bootstrapped graph and is idempotent. Use provider overrides for fakes, not mutable global state. baseUrl defaults to http://elpod.test.

For a focused unit test, instantiate a service with explicit fakes directly. Use a test application when you need route validation, request-scoped DI, native responses, error serialization, health hooks, or plugin composition.

Common mistakes

• Reusing one bootstrapped server across tests that mutate state.
• Forgetting dispose() and leaking timers, queues, or connections.
• Disabling seal broadly instead of fixing the test fixture layout.
• Testing only HTTP status and not response shape, request IDs, cleanup, and auth failures.

Production notes

Use deterministic fake providers and an isolated database/schema. Add integration tests against your real database adapter and broker adapter; an in-memory queue or cache cannot prove distributed guarantees.

Related concepts

Dependency injection · Provider boundaries · Native Elysia routing.