Get Ultra to pretty-print values by default when initializing a REPL using `lein repl :connect`

[venantius]

Get Ultra to pretty-print values by default when initializing a REPL using `lein repl :connect`

[danielytics]

I guess this is because the middleware must be supplied on the nrepl server and lein repl :connect does not start a server. I tested connecting to a server started with lein repl with ultra added and the client I connected seems to pretty print just fine.

I looked at this because I'm manually embedding an nREPL server using clojure.tools.nrepl.server/start-server. You can set a custom handler using the :handler parameter and that the default handler can optionally apply middleware. So I could start my server like this:

(clojure.tools.nrepl.server/start-server
  :port 6789
  :handler (clojure.tools.nrepl.server/default-handler custom-middleware-fn))

So, my question is: is there a way for me to grammatically access ultra's nREPL middleware so that I can add it to my embedded server?

I'm not familiar with leiningen plugins, so don't know if I can just include it as a dependency and pull it out of some var or call some function to generate it.

[venantius]

You're right - I knew this at one point in time and then forgot it and subsequently created this issue 😛

Re: middleware: you can, and you actually don't need to use Ultra to do it (though you can if you like). The middleware that needs to be included server-side is the Whidbey middleware, which is what Ultra uses for pretty-printing values. The relevant blocks of code in Ultra can be found here (https://github.com/venantius/ultra/blob/master/src/ultra/repl/whidbey.clj#L7) and here (https://github.com/venantius/ultra/blob/master/src/ultra/repl.clj#L23) (side note, I hadn't looked at those namespaces in a while but there's a rather ugly circular dependency I'm working around that could easily be circumvented and which I should probably create an issue for).

Anyways, the middleware you want is is in clojure.tools.nrepl.middleware.render-values/render-values, which is a Whidbey ns (it looks like it's from clojure.tools.nrepl, but it's not). Ultra modifies the start-server function to just do a partial in case the user wants to layer additional middleware on top of that.

[danielytics]

Thanks!

On Sun, 17 May 2015 02:03 Ursa americanus kermodei [email protected]
wrote:

Closed #29 #29.

—
Reply to this email directly or view it on GitHub
#29 (comment).