# Testing HTTP Applications

> Testing HTTP Applications: a worked guide from route registry through to a production build.

Source: [https://askrjs.com/docs/guides/testing-http-applications](https://askrjs.com/docs/guides/testing-http-applications)

Status: stable. Packages: @askrjs/testing, @askrjs/server.

**Published packages are authoritative.** Examples may lag behind a published contract. When guidance differs, verify the exports and TypeScript declarations in your installed package, then file an issue.

## Example

Start from an explicit route registry and add one application boundary at a time so browser, server, and production behavior stay testable.

```tsx
export const registry = createRouteRegistry(() => {
  group({ layout: AppLayout }, () => {
    route('/', DashboardPage);
    route('/projects/{projectId}', ProjectPage);
    route('/404', NotFoundPage);
  });
});
```

## Goal and architecture

`@askrjs/testing` drives an Askr server through its Web `Request`/`Response` boundary without opening a port. It's built on standard Web APIs (`Request`/`Response`/`Headers`/`URL`/`ReadableStream`/`AbortController`) with no Node-specific dependency inside the package itself, so "Node-only" describes how it's published and tested today, not a hard technical restriction baked into the implementation. It's runner-neutral and deliberately returns native `Response` objects so Vitest, Node test, or another assertion library can inspect the same contract production adapters receive.

## Request injection

Use `inject(target, input, init?)` for one request, `createTestRequest()` when you need explicit query, JSON, form, header, or abort setup, and `createTestClient(target, options?)` for repeated method calls against one base URL. The target can be a fetch-compatible object or a request handler function; thrown errors and streaming bodies pass through unchanged.

## Cookie and redirect flows

Cookie handling is opt-in. Pass `cookies: true` for a client-private standards-backed jar, or share a jar created by `createTestCookieJar()` across clients. Redirects are manual by default; use `redirect: "follow"` to exercise cookie capture, relative locations, method rewriting, and cross-origin credential stripping without allowing the test to reach the network.

## Verification

Assert the native response status, headers, and body, then cover abort propagation, redirect policy, and cookie scope when the endpoint uses them. Keep transport-adapter tests separate: request injection proves the application contract, while a smaller adapter suite proves Node or another host translates real network requests correctly.

## Documentation navigation

[Previous](https://askrjs.com/docs/guides/testing-deterministic-applications/index.md) | [Next](https://askrjs.com/docs/guides/production-readiness/index.md)