cloudflare2express
an adapter for running a worker or cloudflare pages function in express
The original reason for this was to help @namdevel debug my @rhildred/cors-proxy2. By the time I was done I had a test that worked like this with isomorphic-git, the original target for my cors proxy.
import { describe, it, expect } from 'vitest';
import createApp from '../src/ExpressApp.js';
import git from 'isomorphic-git';
import fs from 'fs';
import http from 'isomorphic-git/http/web';
describe("cloudflare cors-proxy for isomorphic git", ()=>{
it("handles an isomorphic git clone", async ()=>{
const app = createApp();
const server = await app.listen(8080);
await git.clone({
corsProxy: 'http://127.0.0.1:8080/corsproxy',
url: 'https://github.com/diy-pwa/cloudflare2express',
ref: 'main',
singleBranch: true,
depth: 10,
dir: 'test2',
fs: fs,
http
});
await server.close();
expect(true).toBe(true);
});
});I was so excited that I decided to share this so that you can run a cloudflare pages function or worker in the vscode debugger or with supertest tests yourself. There seem to be a lot more workers than pages functions so I also included an example of running a worker as a pages function.
To reproduce this test in your own environment:
nvm use 18
npm install --save-dev vitest express isomorphic-git cloudflare2express @rhildred/cors-proxy2Edit the package.json file to include:
{
"type":"module",
"scripts": {
"test": "rm -rf test2 && vitest run __tests__"
}
}You will need to make a test fixture like below (src/ExpressApp.js)
import express from 'express';
import { onRequest as corsproxy } from '../functions/corsproxy/[[corsproxy]].js';
import {functionsAdapter} from 'cloudflare2express';
export default () => {
const app = express();
app.all(/\/corsproxy.*/, express.raw({
inflate: true,
limit: '50mb',
type: () => true, // this matches all content types for this route
}), async (req, res) => {
functionsAdapter(corsproxy, req, res, {url: req.url.replace(/^.*corsproxy/, "https:/")});
});
return app;
}to adapt the cors-proxy2 worker to a function functions/corsproxy/[[corsproxy]].js:
import {CorsProxyResponse} from "@rhildred/cors-proxy2";
export async function onRequest(context) {
return await CorsProxyResponse.fetch(context.request, context.env);
}For completeness, I made an index.js and start script:
import createApp from './src/ExpressApp.js';
const app = createApp();
const server = await app.listen(8080, ()=>console.log(`listening on port ${server.address().port}`));When we were testing we came across a problem with the inbuilt fetch of node 18. Even though just proxying, node would try to uncompress the response and fail. There is a solution to that problem, using node-fetch, in https://github.com/rhildred/cors-proxy2.
Unfortunately I didn't get multipart form data working with the express adapter. The anticipated use for the express adapter is for running the debugger and supertest so I satisfied myself with this.
I hope that you also discover the joy of being able to write tests with your cloudflare workers and pages functions and debug them in vscode on your local machine.