Calva: Clojure & ClojureScript support for VS Code

Integrated REPL, linting, inline eval, test runner, and more. Powered by Cider & nRepl.

Raison d´être

Try to bring some of the Emacs CIDER experience to VS Code. Supporting both Clojure and ClojureScript. Hopefully lowering the barriers to the Clojarian world. If we can bring some productive concepts from other Clojure dev environments, like Cursive, to VSCode as well, we will.

Demo: evaluate inline

Features

At a glance

• Evaluate code inline
• Run tests
• Integrated repls (using the VS Code Terminal)
• Intellisense
• Underlining compile-time errors
• Go to / Peek at definition
• View docstrings on hover
• View function signatures on hover
• Supports all clojure filetypes, clj, cljc and cljs.
• Easy toggle between clj and cljs repl for cljc files
• Autoindent according to: https://github.com/bbatsov/clojure-style-guide
• Enables clj evaluation of clojure code in all files (e.g. Markdown, etcetera).
• Support for shadow-cljs.

Demo: switch between clj and cljs repl sessions for cljc files:

More in depth (and some usage info)

• Running tests through the REPL connection, and mark them in the Problems tab
  • Run namespace tests: ctrl+alt+v t
  • Run all tests: ctrl+alt+v shift+t
  • Rerun previously failing tests: ctrl+alt+v ctrl+t
  • Marks test failures using the Problem tab
  • User setting for running namespace tests on save (defaults to on)
  • Caveat: Right now the tests are reported only when all are run, making it painful to run all tests in larger projects. I'll fix it. Promise!
• Code evaluation
  • Evaluate code and show the results as annotation in the editor: ctrl+alt+v e
  • Evaluate code and replace it in the editor, inline: ctrl+alt+v r
  • Pretty printing evaluation resuls: ctrl+alt+v p
  • Error information when evaluation fails (at least a hint)
  • Support for cljc files and you can choose if they should be evaluated by the clj or the cljc repl session.
  • Enables clj repl for all files/editors. You now can evaluate those clojure code snippets in Markdown files.
  • The evaluation commands will auto-”detect” vectors and maps as well as list.
  • User setting to evaluate namespace on save/open file (defaults to on)
• Integrated REPLs using the Terminal tab
  • Switch to current namespace in the terminal REPL: ctrl+alt+v n
  • Load current namespace in the terminal REPL: ctrl+alt+v alt+n
  • Evaluate code from the editor to the terminal REPL: ctrl+alt+v alt+e
• When editing cljc files, easily choose if repl commands should go to the clj or cljs repl by clicking the cljc/clj[s] indicator in the status bar.
• Selection of current form: ctrl+alt+v s. Auto-detected the same way as for evaluation. Will select the form preceding or following the cursor first, otherwise the form the cursor is inside. (Only when the cursor is directly adjacent to any bracket so far.)

Demo: Peek at defintions, etcetera:

Demo: lint errors are marked in the editor. (As are unit test failures)

Future Stuff

• Test reporting while tests are being run. HIGH PRIORITY.
• Open as many REPLs as you like.
• Custom user commands to execute over the REPL connection.
• Commands to start the REPLs from VS Code, injecting dependencies automatically.
• List symbols in the current file.
• Let us know what you want. PRs welcome, file an issue or tweet: @pappapez

How to use

Calva connects to a running nrepl session, so you need to start that outside Calva, then connect (ctrl+alt+v c).

It has dependencies on toots/nrepl and cider/nrepl.

Please make sure to read the Getting started page on the wiki. It has more instructions and information.

Other

Built on Visual Clojure

Calva started off as a clone of the promising (but abandoned) visual:clojure extension.

Team

We are now two, so that's a team. Calva is a dear project to us so we try to give it of our precious spare time.

• Peter Strömberg
• Pedro Girardi
• Your name here

How to contribute

Calva is being ported to ClojureScript and uses the shadow-cljs toolchain.

See the How to Contribute page on the wiki for instructions on how to hack on Calva.

Happy coding

We hope you will find tons of use for this extension! Please let us know what you think or want. PRs welcome, file an issue or chat us (@pez, @pedrorgirardi) up in the #editors channel of the Clojurians Slack. Tweeting @pappapez works too.

❤️