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clojure-lsp Development#

There are several ways of finding and fixing a bug or implementing a new feature:

  • The Clojure Way
  • Create a test for your bug/feature, then implement the code following the test (TDD).
  • Build clojure-lsp using make each time you have made changes, and test it manually in your client. This is the slowest option.

Whichever development path you choose: For final testing, it is good to rebuild the binary with make.

There are two custom LSP methods clojure/serverInfo/log and clojure/cursorInfo/log. They can assist in debugging.

The Clojure Way#

With a clojure-lsp + nREPL powered Clojure editor you can modify your editor session's clojure-lsp server using the Clojure REPL.

Here's demo video: https://www.youtube.com/watch?v=4UvT0yqBDw8

These are the steps:

  1. Configure your editor to use the clojure-lsp executable from this project
  2. make - to build the clojure-lsp executable
  3. Have your editor restart its clojure-lsp server
  4. Issue the clojure-lsp serverInfo command
  5. Find the port entry in the output
  6. Connect your editors nREPL client to this port
  7. Hack away!

Seeing is believing. An easy way to convince yourself that you can actually change clojure-lsp mid-flight is to:

  1. Modify the server-info function in src/clojure_lsp/handlers.clj
    • Say, you add a :foo :bar entry to the map returned
  2. Evaluate the new server-info function definition
  3. Issue the clojure-lsp serverInfo command
  4. Find :foo :bar in the output

You have just modified the LSP server powering your editor while it was running! This is the Clojure way. No recompiling and restarting and reloading. That is some other, non-Clojure, way.

The details in how to perform these steps can vary a bit between the various Clojure editors/plugins.

Visual Studio Code with Calva#

  • This project comes with Calva configuration to use the clojure-lsp executable built in step 2 above. You can skip step 1.
  • To restart the clojure-lsp server, use the VS Code command Developer: Reload Window
  • The Hack away! step needs to start with you issuing the command Calva: Load Current File and Dependencies.

Emacs with CIDER#

TBD. PR welcome.

Your Favorite Editor#

TBD. PR welcome.


Last update: December 7, 2021