nbb nrepl-server: can't send expressions from .cljs file

[borkdude]

Expected behavior

I expect to be able to send expressions from a .cljs file in clojurescript-mode to an nbb nrepl server.

Actual behavior

Nothing happens until I activate clojure-mode in a .cljs file.

Steps to reproduce the problem

npm install -g nbb
nbb nrepl-server :port 1338

Then cider-connect from emacs to that server and try to evaluate some expressions from a .cljs file:

foo.cljs:

(defn version []
  js/process.version)

(version)

(require '["fs" :as fs])

(fs/existsSync "README.md")
(fs/existsSync "README2.md")

(require '[clojure.string :as str])

(first (str/split js/process.env.PATH ":"))

Environment & Version information

CIDER version information

Include here the version string displayed when
CIDER's REPL is launched. Here's an example:

;; Connected to nREPL server - nrepl://localhost:1337
;; CIDER 1.2.0snapshot (package: 20210914.1315)

Emacs version

27.2

Operating system

macOS

[bbatsov]

Do you have the same problem with cider-connect-cljs? I'm guess "yes" as this still assumes the Clojure nREPL server, but I'm asking just in case.

[borkdude]

With cider-connect-cljs it's the same + the clojure-mode workaround doesn't work there.

[bbatsov]

Got it.

[bbatsov]

I finally looked at this and the problem is that when you use cider-connect this is actually cider-connect-clj, which sets the connection type automatically to Clojure. Then if you try to evaluate something from a cljs file CIDER is looking for a cljs REPL, which it can't find. That's why switching to clojure-mode fixed this. I'll have to think a bit how to best approach this, but it shouldn't be hard to fix.

I guess we'll have to add some simple detection that we're connected to nbb and just skip the regular cljs init sequence (as for all other REPLs first we started a Clojure connection that gets upgraded to ClojureScript by evaluating a bit of "magic" code). Clearly, that's not need for a native ClojureScript REPL like nbb.

[borkdude]

Thanks for looking into this.

[benjamin-asdf]

with cider 318fe6878d8bedf5db9dfa649dedb45d72b2e7ee
I try

• run nbb nrepl-server :port 1338
• cider-connect-clj
• then cider tries to call some classpath functions or something that are not there
  falls back to reading from minibuffer

output from nbb server:

Connection accepted
request {:op "clone", :id "1"}
response {"new-session" "a70ec1ab-299e-494f-a6d9-c83c54e36511", "status" ["done"], 
"id" "1"}
request {:op "clone", :id "2"}
response {"new-session" "e4b9cc25-91a2-48b5-bd24-b13dbccc6035", "status" ["done"], 
"id" "2"}
request {:op "describe", :session "a70ec1ab-299e-494f-a6d9-c83c54e36511", :id "3"}
response {"versions" {"nbb-nrepl" {"major" "TODO", "version-string" "TODO"}, "node"
 {"major" "v17", "minor" "3", "incremental" "0", "version-string" "v17.3.0"}}, "aux
" {}, "ops" {"eval" {}, "describe" {}, "clone" {}, "close" {}, "load-file" {}}, "st
atus" ["done"], "id" "3", "session" "a70ec1ab-299e-494f-a6d9-c83c54e36511"}
request {:nrepl.middleware.print/buffer-size 4096, :file "*cider-repl clojure/nbb-d
ropdown:localhost:1338(clj)*", :nrepl.middleware.print/quota 1048576, :nrepl.middle
ware.print/print "cider.nrepl.pprint/pprint", :op "eval", :column 1, :line 3, :id "
4", :code "(clojure.core/apply clojure.core/require clojure.main/repl-requires)", :
inhibit-cider-middleware "true", :nrepl.middleware.print/stream? "1", :nrepl.middle
ware.print/options {:right-margin 70}, :session "a70ec1ab-299e-494f-a6d9-c83c54e365
11"}
response {"err" "Could not resolve symbol: clojure.main/repl-requires\n", "id" "4",
 "session" "a70ec1ab-299e-494f-a6d9-c83c54e36511"}
response {"ex" "#error {:message \"Could not resolve symbol: clojure.main/repl-requ
ires\", :data {:type :sci/error, :line 1, :column 42, :file nil, :phase \"analysis\
"}}", "ns" "user", "status" ["done"], "id" "4", "session" "a70ec1ab-299e-494f-a6d9-
c83c54e36511"}
request {:op "eval", :code "(seq (.split (System/getProperty \"java.class.path\") \
":\"))", :session "e4b9cc25-91a2-48b5-bd24-b13dbccc6035", :id "5"}
response {"err" "Could not resolve symbol: System/getProperty\n", "id" "5", "sessio
n" "e4b9cc25-91a2-48b5-bd24-b13dbccc6035"}
response {"ex" "#error {:message \"Could not resolve symbol: System/getProperty\", 
:data {:type :sci/error, :line 1, :column 15, :file nil, :phase \"analysis\"}}", "n
s" "user", "status" ["done"], "id" "5", "session" "e4b9cc25-91a2-48b5-bd24-b13dbccc
6035"}
request {:op "eval", :code "(seq (.split (System/getProperty \"java.class.path\") \
":\"))", :session "e4b9cc25-91a2-48b5-bd24-b13dbccc6035", :id "6"}
response {"err" "Could not resolve symbol: System/getProperty\n", "id" "6", "sessio
n" "e4b9cc25-91a2-48b5-bd24-b13dbccc6035"}
response {"ex" "#error {:message \"Could not resolve symbol: System/getProperty\", 
:data {:type :sci/error, :line 1, :column 15, :file nil, :phase \"analysis\"}}", "n
s" "user", "status" ["done"], "id" "6", "session" "e4b9cc25-91a2-48b5-bd24-b13dbccc
6035"}

cider-repl contents:

;; Connected to nREPL server - nrepl://localhost:1338
;; CIDER 1.3.0-snapshot (package: 1.3.0-snapshot)
Could not resolve symbol: clojure.main/repl-requires
user> 

And here is the stacktrace for the "List expression" read from minibuffer call (which feels like a bug in that situation)

Debugger entered--Lisp error: (minibuffer-quit)
  #<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_57>()
  read-minibuffer("Lisp expression: ")
  cider-fallback-eval:classpath()
  cider-classpath-entries()
  #f(compiled-function (system session) "Check if SESSION is a friendly session." #<bytecode -0x649c99c46adde4>)(CIDER ("clojure/nbb-dropdown:localhost:1338" #<buffer *cider-repl clojure/nbb-dropdown:localhost:1338(clj)*>))
  apply(#f(compiled-function (system session) "Check if SESSION is a friendly session." #<bytecode -0x649c99c46adde4>) CIDER ("clojure/nbb-dropdown:localhost:1338" #<buffer *cider-repl clojure/nbb-dropdown:localhost:1338(clj)*>))
  sesman-friendly-session-p(CIDER ("clojure/nbb-dropdown:localhost:1338" #<buffer *cider-repl clojure/nbb-dropdown:localhost:1338(clj)*>))
  #f(compiled-function (ses) #<bytecode 0xa02ea2209b5b91>)(("clojure/nbb-dropdown:localhost:1338" #<buffer *cider-repl clojure/nbb-dropdown:localhost:1338(clj)*>))
  #f(compiled-function (elt) #<bytecode -0x14816b7dbc015a5f>)(("clojure/nbb-dropdown:localhost:1338" #<buffer *cider-repl clojure/nbb-dropdown:localhost:1338(clj)*>))
  mapcar(#f(compiled-function (elt) #<bytecode -0x14816b7dbc015a5f>) (("clojure/support-bot:localhost:38341" #<buffer *cider-repl clojure/support-bot:localhost:38341(clj)*>) ("clojure/support-bot:localhost:7000" #<buffer *cider-repl clojure/support-bot:localhost:7000(clj)*>) ("clojure/aws-play:localhost:46141" #<buffer *cider-repl clojure/aws-play:localhost:46141(clj)*>) ("clojure/support-bot:localhost:44177" #<buffer *cider-repl clojure/support-bot:localhost:44177(clj)*>) ("clojure/support-bot:localhost:45165" #<buffer *cider-repl clojure/support-bot:localhost:45165(clj)*>) ("clojure/reply-bot:localhost:42139" #<buffer *cider-repl clojure/reply-bot:localhost:42139(clj)*>) ("clojure/nbb-dropdown:localhost:1338" #<buffer *cider-repl clojure/nbb-dropdown:localhost:1338(clj)*>)))
  #f(compiled-function #'sequence #<bytecode 0x1842db430419e5f4>)(#f(compiled-function (elt) #<bytecode -0x14816b7dbc015a5f>) (("clojure/support-bot:localhost:38341" #<buffer *cider-repl clojure/support-bot:localhost:38341(clj)*>) ("clojure/support-bot:localhost:7000" #<buffer *cider-repl clojure/support-bot:localhost:7000(clj)*>) ("clojure/aws-play:localhost:46141" #<buffer *cider-repl clojure/aws-play:localhost:46141(clj)*>) ("clojure/support-bot:localhost:44177" #<buffer *cider-repl clojure/support-bot:localhost:44177(clj)*>) ("clojure/support-bot:localhost:45165" #<buffer *cider-repl clojure/support-bot:localhost:45165(clj)*>) ("clojure/reply-bot:localhost:42139" #<buffer *cider-repl clojure/reply-bot:localhost:42139(clj)*>) ("clojure/nbb-dropdown:localhost:1338" #<buffer *cider-repl clojure/nbb-dropdown:localhost:1338(clj)*>)))
  apply(#f(compiled-function #'sequence #<bytecode 0x1842db430419e5f4>) #f(compiled-function (elt) #<bytecode -0x14816b7dbc015a5f>) (("clojure/support-bot:localhost:38341" #<buffer *cider-repl clojure/support-bot:localhost:38341(clj)*>) ("clojure/support-bot:localhost:7000" #<buffer *cider-repl clojure/support-bot:localhost:7000(clj)*>) ("clojure/aws-play:localhost:46141" #<buffer *cider-repl clojure/aws-play:localhost:46141(clj)*>) ("clojure/support-bot:localhost:44177" #<buffer *cider-repl clojure/support-bot:localhost:44177(clj)*>) ("clojure/support-bot:localhost:45165" #<buffer *cider-repl clojure/support-bot:localhost:45165(clj)*>) ("clojure/reply-bot:localhost:42139" #<buffer *cider-repl clojure/reply-bot:localhost:42139(clj)*>) ("clojure/nbb-dropdown:localhost:1338" #<buffer *cider-repl clojure/nbb-dropdown:localhost:1338(clj)*>)) nil)
  seq-map(#f(compiled-function (elt) #<bytecode -0x14816b7dbc015a5f>) (("clojure/support-bot:localhost:38341" #<buffer *cider-repl clojure/support-bot:localhost:38341(clj)*>) ("clojure/support-bot:localhost:7000" #<buffer *cider-repl clojure/support-bot:localhost:7000(clj)*>) ("clojure/aws-play:localhost:46141" #<buffer *cider-repl clojure/aws-play:localhost:46141(clj)*>) ("clojure/support-bot:localhost:44177" #<buffer *cider-repl clojure/support-bot:localhost:44177(clj)*>) ("clojure/support-bot:localhost:45165" #<buffer *cider-repl clojure/support-bot:localhost:45165(clj)*>) ("clojure/reply-bot:localhost:42139" #<buffer *cider-repl clojure/reply-bot:localhost:42139(clj)*>) ("clojure/nbb-dropdown:localhost:1338" #<buffer *cider-repl clojure/nbb-dropdown:localhost:1338(clj)*>)))
  seq-filter(#f(compiled-function (ses) #<bytecode 0xa02ea2209b5b91>) (("clojure/support-bot:localhost:38341" #<buffer *cider-repl clojure/support-bot:localhost:38341(clj)*>) ("clojure/support-bot:localhost:7000" #<buffer *cider-repl clojure/support-bot:localhost:7000(clj)*>) ("clojure/aws-play:localhost:46141" #<buffer *cider-repl clojure/aws-play:localhost:46141(clj)*>) ("clojure/support-bot:localhost:44177" #<buffer *cider-repl clojure/support-bot:localhost:44177(clj)*>) ("clojure/support-bot:localhost:45165" #<buffer *cider-repl clojure/support-bot:localhost:45165(clj)*>) ("clojure/reply-bot:localhost:42139" #<buffer *cider-repl clojure/reply-bot:localhost:42139(clj)*>) ("clojure/nbb-dropdown:localhost:1338" #<buffer *cider-repl clojure/nbb-dropdown:localhost:1338(clj)*>)))
  sesman--friendly-sessions(CIDER sort)
  sesman-current-sessions(CIDER (project))
  cider--check-existing-session((:project-dir "~/repos/clojure/nbb-dropdown/" :host "localhost" :port 1338))
  cider-connect-clj(nil)
  funcall-interactively(cider-connect-clj nil)
  command-execute(cider-connect-clj)

[vxe]

any updates?

[bbatsov]

Had no time for this so far. The way things are going it's unlikely that I'll be able to tackle it before April/May. If someone wants to beat me to it - be my guest.

[jackrusher]

(It's not just nbb, btw. I also have some "connect directly to a clojurescript REPL" stuff happening that would benefit greatly from being able to evaluate forms while in CLJS mode.)

[borkdude]

@bbatsov I'm probably going to look into this next Monday/Tuesday. Any pointers that will set me on the right track will be appreciated. As cider-connect is an alias for cider-connect-clj, where should we start? I assume we should support cider-connect-cljs instead? Or should we have a cider-connect-generic alternative that doesn't assume anything but just plays by the rules of the nREPL "spec"?

[jackrusher]

Looking at the spec and a trace of an nREPL session between cider and a jack'd in JVM, it appears that cider wants a few non-standard ops and falls back to trying to execute JVM-specific code when they're absent. (For example, cider seems to want a stacktrace op, and falls back to calling (clojure.stacktrace/print-cause-trace *e) directly if it isn't available.

Should we discuss improving the protocol a bit?

[borkdude]

I think this isn't a protocol problem, it's a problem of a client that expects the nREPL server to be of a certain implementation (JVM Clojure) rather than expecting it to just talk nREPL and implement the specification. Or maybe it is this way because the protocol isn't rich or specified/documented enough?