hono-testkit: in-memory Cloudflare bindings for Hono tests

[md-sagban]

Hi everyone,

I built hono-testkit while working on tests for Hono applications that use Cloudflare bindings. I wanted a simple way to test routes with controlled state without connecting to real Cloudflare resources or starting a Workers runtime for every test.

The package currently provides:

• a typed Hono request harness and isolated test suites
• in-memory mocks for KV, D1, R2, Queues, and Service Bindings
• an ExecutionContext mock with support for draining waitUntil() work
• a request builder for headers, cookies, bearer tokens, JSON, and forms
• ESM and CommonJS builds with separate TypeScript declarations

The core package does not depend on a test runner. I have documented examples for Vitest, Jest, node:test, and Bun.

import { Hono } from "hono";
import { createHonoTestHarness, mockKV } from "hono-testkit";

const bindings = { CACHE: mockKV() };
const app = new Hono<{ Bindings: typeof bindings }>();

app.post("/cache", async (c) => {
  await c.env.CACHE.put("key", "value");
  return c.json({ ok: true });
});

const harness = createHonoTestHarness(app, bindings);
const response = await harness.post("/cache");

This is not intended to replace Cloudflare's Vitest integration. Runtime-specific behavior, persistence, concurrency, and Durable Objects should still be tested with workerd. The package is for fast unit and route tests where deterministic bindings are more useful than runtime fidelity.

Version 0.1.0 is available now:

• npm: https://www.npmjs.com/package/hono-testkit
• GitHub: https://github.com/md-sagban/hono-testkit
• Documentation: https://github.com/md-sagban/hono-testkit/blob/main/docs/getting-started.md

I would appreciate feedback from people testing Hono applications on Cloudflare, especially about missing binding behavior or APIs that feel awkward in real test suites.