@kozojs/testing

In-process test client for Kozo framework — no HTTP server required.

Install

npm install -D @kozojs/testing

Quick Start

import { createKozo, z } from '@kozojs/core';
import { createTestClient } from '@kozojs/testing';

const app = createKozo();
app.get('/ping', {}, () => ({ pong: true }));

const client = createTestClient(app);
const res = await client.get('/ping');

expect(res.status).toBe(200);
expect(res.json()).toEqual({ pong: true });

API

createTestClient(app)

Wrap an existing Kozo app. Routes are invoked in-memory via app.fetch() — no port is opened.

const client = createTestClient(app);

// All HTTP methods available
await client.get('/users');
await client.post('/users', { name: 'Alice', email: '[email protected]' });
await client.put('/users/1', { name: 'Bob' });
await client.patch('/users/1', { name: 'Charlie' });
await client.delete('/users/1');

createTestApp(config?)

Create a Kozo app and client in one call — ideal for tests.

import { z } from '@kozojs/core';
import { createTestApp } from '@kozojs/testing';

const { app, get, post } = createTestApp();

app.post('/users', {
  body: z.object({ name: z.string(), email: z.string().email() }),
}, ({ body }) => ({ id: 1, ...body }));

const res = await post('/users', { name: 'Alice', email: '[email protected]' });
expect(res.status).toBe(200);
expect(res.json()).toMatchObject({ name: 'Alice' });

inject(options)

Low-level request with full control:

const res = await client.inject({
  method: 'POST',
  url: '/users',
  headers: { Authorization: 'Bearer token123' },
  body: { name: 'Alice' },
  query: { expand: 'profile' },
});

Response Object

| Property | Type | Description | |---|---|---| | status | number | HTTP status code | | headers | Headers | Response headers (Web API) | | body | string | Raw response body as text | | ok | boolean | true if status is 200–299 | | json<T>() | T | Parse body as JSON |

Validation Errors

Structured Zod validation errors are returned as 400 responses:

const res = await post('/users', { name: 'Alice', email: 'not-an-email' });
expect(res.status).toBe(400);
expect(res.json()).toMatchObject({
  status: 400,
  title: 'Validation Failed',
  errors: [{ field: 'email', code: 'invalid_string', message: expect.any(String) }],
});

Services

Works seamlessly with typed services:

const { app, get } = createTestApp<{ db: Database }>({
  services: { db: mockDb },
});

app.get('/users', {}, ({ services }) => services.db.getUsers());

License

MIT