Fix #1592 (2): reduce image size (#1602)

src/babashka/impl/sci.clj

@@ -1,8 +1,52 @@
 (ns babashka.impl.sci
   {:no-doc true}
-  (:require [sci.core :as sci]))
+  (:require [sci.core :as sci]
+            [sci.ctx-store :as store]))
 
 (def sns (sci/create-ns 'sci.core nil))
 
+(defmacro copy-ns
+    "Returns map of names to SCI vars as a result of copying public
+  Clojure vars from ns-sym (a symbol). Attaches sci-ns (result of
+  sci/create-ns) to meta. Copies :name, :macro :doc, :no-doc
+  and :argslists metadata.
+
+  Options:
+
+  - :exclude: a seqable of names to exclude from the
+  namespace. Defaults to none.
+
+  - :copy-meta: a seqable of keywords to copy from the original var
+  meta.  Use :all instead of a seqable to copy all. Defaults
+  to [:doc :arglists :macro].
+
+  - :exclude-when-meta: seqable of keywords; vars with meta matching
+  these keys are excluded.  Defaults to [:no-doc :skip-wiki]
+
+  The selection of vars is done at compile time which is mostly
+  important for ClojureScript to not pull in vars into the compiled
+  JS. Any additional vars can be added after the fact with sci/copy-var
+  manually."
+    ([ns-sym sci-ns] `(sci.core/copy-ns ~ns-sym ~sci-ns nil))
+    ([ns-sym sci-ns opts]
+     ;; this branch is hit by macroexpanding in JVM Clojure, not in the CLJS compiler
+     (let [publics-map (sci/eval-form (store/get-ctx) (list 'ns-publics (list 'quote ns-sym)))
+           publics-map (#'sci/process-publics publics-map opts)
+           mf (#'sci/meta-fn (:copy-meta opts))
+           publics-map (#'sci/exclude-when-meta
+                        publics-map
+                        meta
+                        (fn [k]
+                          (list 'quote k))
+                        (fn [var m]
+                          {:name (list 'quote (:name m))
+                           :var var
+                           :meta (list 'quote (mf m))})
+                        (or (:exclude-when-meta opts)
+                            [:no-doc :skip-wiki]))]
+       `(sci.core/-copy-ns ~publics-map ~sci-ns))))
+
 (def sci-core-namespace
-  (sci/copy-ns sci.core sns))
+  (assoc (sci/copy-ns sci.core sns {:exclude [copy-ns]})
+         'copy-ns (sci/copy-var copy-ns sns)
+         '-copy-ns (sci/copy-var sci/-copy-ns sns)))

test/babashka/sci_test.clj

@@ -0,0 +1,14 @@
+(ns babashka.sci-test
+  (:require
+   [babashka.test-utils :as tu]
+   [clojure.edn :as edn]
+   [clojure.test :as t :refer [deftest is]]))
+
+(deftest sci-test
+  (is (= 1 (edn/read-string
+            (tu/bb nil "-e" "
+(ns foo)
+(require '[sci.core :as sci])
+(def x 1)
+(def ctx (sci/init {:namespaces {'foo (sci/copy-ns foo (sci/create-ns 'foo))}}))
+(sci/eval-string* ctx \"foo/x\")")))))