cljs cloudflare worker

Example for using CLJS to create a Cloudflare worker.

The cljs-worker dir was created via npx wrangler generate my-project worker and the wranger.toml updated to use the out/main.js file instead of index.js. out/main.js is the file created by shadow-cljs as per the shadow-cljs.edn :worker build config.

Development

npx shadow-cljs watch worker
npx wranger -c cljs-worker/wranger.toml dev

The runtime doesn't seem to allow IO outside of request handlers, thus a websocket connection for the REPL is not supported. If you still want a REPL while development you can run npx shadow-cljs node-repl to get one. It won't be in the wrangler runtime though. I have never used this in anger, so I'm not sure how useful a REPL into the process would be. It seems to be reset for every request anyway.

Deploy

rm -rf cljs-worker/out
npx shadow-cljs release worker
npx wranger ...

I did not test the deploy part, since I do not have a cloudflare account. I'm confident it'll just work though.