REPL driven development bug repro

This is a minimal test case of a bug where changing and re-evaluating a function in another namespace does not update if that function has an identical name to a function in the core namespace, and the calling function's definition hasn't been separately evaluated (i.e. only the whole buffer has been evaluated, once or more).

Reproduce with REPL connected editor

Launch a REPL with what you need to eval things in your editor, for example

$ clj -Sdeps '{:deps {nrepl/nrepl {:mvn/version "0.9.0"} cider/cider-nrepl {:mvn/version "0.28.3"}}}'  -m nrepl.cmdline  --middleware '["cider.nrepl/cider-middleware"]' --interactive

Evaluate src/repro.clj in your REPL, and follow the commented instructions in that file.

Reproduce with non REPL editor

Paste to clj prompt

(require 'repro)
(repro/func-b)

edit prints in repro2.clj and paste again:

(require 'repro2 :reload)
(repro/func-b)
(repro2/read)
(require 'repro :reload)
(repro/func-b)

Does not reproduce with just clj

(ns repro2)

(defn read []
   (prn "Called repro2/read 1"))

(defn read2 []
   (prn "Called repro2/read2 1"))

(ns repro
  (:require [repro2]))

(defn func-b []
  (prn "Called func-b: 1")
  (repro2/read)
  (repro2/read2))

(func-b)

(in-ns 'repro2)

(defn read []
   (prn "Called repro2/read 2"))

(defn read2 []
   (prn "Called repro2/read2 2"))

(in-ns 'repro)

(func-b)

(defn func-b []
  (prn "Called func-b: 2")
  (repro2/read)
  (repro2/read2))

(func-b)

Notes

(require '[clojure.tools.namespace.repl :refer [refresh]])
(refresh)

does work, but has to be used after every change (i.e. it does not have a similar effect to just re-evaling the func-b definition).