Tamperweasel

Load a ClojureScript REPL on any site by simply enabling a userscript, or using a <script src="..."/> block in your HTML.

The WebSocket connection is created by the Weasel library, and I personally use Tampermonkey to manage my userscripts, hence the name of this repo.

To use:

1. Install Weasel and ClojureScript to your Clojure environment. This might be the deps.edn in your project folder, or $HOME/.clojure/deps.edn for a “global” install.
2. You need a server that’s going to A. host your ClojureScript REPL, B. host the WebSocket connection with your browser. You can run both in the same Clojure process with the code below. I usually put the code below in a tamperweasel.clj, and run with clj -M tamperweasel.clj.

(require '[clojure.core.server])
(require '[weasel.repl.websocket])

(clojure.core.server/start-server
 {:accept        'cljs.core.server/io-prepl
  :address       "127.0.0.1"
  :port          6776
  :name          "build"
  :args          [:repl-env (weasel.repl.websocket/repl-env :ip "0.0.0.0" :port 9001)]
  :server-daemon false})

1. In your userscript manager, add https://raw.githubusercontent.com/neilyio/tamperweasel/master/dist/tamperweasel.js as a script. Enable it, and browse to a web page. If you’re loading your own HTML file, you can link this in a <script src="..."/> block.
2. Once both your Clojure server (clj -M tamperweasel.clj) and your userscript are running, connect to the Clojure server’s pREPL at port 6776 in Emacs or your favorite editor. Note that the WebSocket connection between Clojure and browser won’t be initiated until after you’ve connected successfully to the pREPL.

Now evaluate some ClojureScript, and take over the web! More info coming soon about how to set up other REPLs (nREPL, socket REPL), as well as how to add dependencies.

Compiling

The latest version of tamperweasel.js is committed to the repo in dist/tamperweasel.js. Unless you’re making changes to the source code, just load that one as your userscript.

To compile, make sure you have shadow-cljs installed globally.

The namespace with the WebSocket logic is tamperweasel.core.

The build scripts is in tamperweasel.build.

The final output is dist/tamperweasel.js.

To compile dist/tamperweasel.js:

shadow-cljs run scripts.build/build