In this section we’ll briefly examine some common configuration options related to ClojureScript. Configuration that is specific to a particular REPL (e.g. shadow-cljs) is covered separately in the individual REPL setup sections.

Modifying the ClojureScript jack-in dependencies

Out-of-the-box, CIDER injects a single dependency into ClojureScript REPLs - namely piggieback. If you’d like to inject more deps you’ll have to modify the cider-jack-in-cljs-dependencies variable. Here’s an example:

;; let's add Weasel on jack-in
(cider-add-to-alist 'cider-jack-in-cljs-dependencies "weasel/weasel" "0.7.1")
Always use the fully qualified group/artifact (e.g. re-frame/re-frame) in these dependencies, since only Leiningen supports the bare re-frame syntax.

Typically, modifying this variable is not needed, as ClojureScript dependencies are declared explicitly in your project configuration most of the time.

Modifying this variable will affect all ClojureScript REPL types.

Setting a Default ClojureScript REPL Type

If you frequently use the same ClojureScript REPL, you can set cider-default-cljs-repl and CIDER will skip the prompt and use this instead. For example, the following will make Node.js the default:

(setq cider-default-cljs-repl 'node)

Defining Custom ClojureScript REPL Types

All supported ClojureScript REPLs are stored in cider-cljs-repl-types. If you need to extend it, you should use cider-register-cljs-repl-type in your Emacs configuration.

(cider-register-cljs-repl-type 'super-cljs "(do (...))" optional-requirements-function)
If you’re registering a self-hosted (native) ClojureScript REPL (e.g. scittle), the "upgrade" form should be nil.

You can also modify the known ClojureScript REPLs on a per-project basis using .dir-locals.el:

;; replace the list of REPL types and set some default
  (cider-default-cljs-repl . super-cljs)
  (cider-cljs-repl-types . ((super-cljs "(do (foo) (bar))")))))
;; modify the list of known REPLs and set some default
  (eval . (cider-register-cljs-repl-type 'super-cljs "(do (foo) (bar))"))
  (cider-default-cljs-repl . super-cljs)))

For one-off REPLs you can also use the custom REPL init form like this:

;; modify the list of known REPLs and set some default
  (cider-custom-cljs-repl-init-form . "(do (foo) (bar))"
  (cider-default-cljs-repl . custom)))

If you already have a Clojure REPL running and want to add a ClojureScript REPL, you can invoke cider-jack-in-sibling-clojurescript to add it.

Enhanced Completion

By default CIDER will enrich the ClojureScript completion results using the suitable library. If case you run into any suitable-related issues you can disable the enhanced completion like this:

(setq cider-enhanced-cljs-completion-p nil)