intern fails to rebind a referred var if that var is present in the "user" namespace

[sritchie]

version

0.2.7

platform

JVM:

openjdk version "17.0.1" 2021-10-19 LTS
OpenJDK Runtime Environment Zulu17.30+15-CA (build 17.0.1+12-LTS)
OpenJDK 64-Bit Server VM Zulu17.30+15-CA (build 17.0.1+12-LTS, mixed mode, sharing)

problem

ns-unmap and intern are not successful at rebinding a referred var if that var shares a name with an existing var supplied via the 'user namespace or the :bindings context options key.

repro

(require '[sci.core :as sci])
(require '[clojure.test :refer [is]])

(let [remote {'cake "cake"}
        opts {:namespaces {'remote remote}
              :bindings {'cake "new-cake"}}]
    ;; First confirm that `cake` evaluates to "new-cake":
    (is (= "new-cake"
           (sci/eval-form (sci/init opts) 'cake)))

    ;; I can overwrite bindings with `ns-unmap` and `intern`:
    (is (= "bar"
           (sci/eval-form
            (sci/init opts)
            '(do (ns-unmap *ns* 'cake)
                 (intern *ns* 'cake "bar")
                 cake))))

    ;; BUG: Rebinding a referred var using `ns-unmap` and `intern` fails when
    ;; some var of the same name was set using the `:bindings` key.
    (is (= "cake"
           (sci/eval-form
            (sci/init opts)
            '(do (require '[remote :refer [cake]])
                 (ns-unmap *ns* 'cake)
                 (intern *ns* 'cake "bar")
                 cake))))

    ;; This is also a problem if the initial bindings are supplied to the
    ;; `'user` namespace (I am pretty sure these are equivalent)
    (is (= "cake"
           (sci/eval-form
            (sci/init (-> opts
                          (dissoc :bindings)
                          (assoc-in [:namespaces 'user] (:bindings opts))))
            '(do (require '[remote :refer [cake]])
                 (ns-unmap *ns* 'cake)
                 (intern *ns* 'cake "bar")
                 cake))))

    ;; If `'cake` is not present in bindings, or if `:bindings` is gone, the bug
    ;; goes away and we can rebind the referred var:
    (is (= "bar"
           (sci/eval-form
            (sci/init (update opts :bindings  dissoc 'cake))
            '(do (require '[remote :refer [cake]])
                 (ns-unmap *ns* 'cake)
                 (intern *ns* 'cake "bar")
                 cake)))))

[borkdude]

Should be fixed on master.

[sritchie]

Thank you!