erlang: code:purge/1 + code:soft_purge/1 (+10 eval tests)

lib/erlang/tests/eval.sx

@@ -1157,6 +1157,58 @@
   (nm (ev "element(2, code:load_binary(\"cl1\", \"x.erl\", \"-module(cl1). f() -> 0.\"))"))
   "badarg")
 
+
+;; ── Phase 7: code:purge/1 + code:soft_purge/1 ───────────────────
+(er-modules-reset!)
+
+;; purge unknown module → false
+(er-eval-test "code:purge unknown"
+  (nm (ev "code:purge(nope)")) "false")
+
+;; load, then purge without old version → false (nothing to purge)
+(er-eval-test "code:purge no old"
+  (nm (ev "code:load_binary(pg1, \"pg1\", \"-module(pg1). v() -> 1.\"), code:purge(pg1)"))
+  "false")
+
+;; load v1, load v2 (creates :old), purge with no live procs → true
+(er-eval-test "code:purge after reload"
+  (nm (ev "code:load_binary(pg2, \"pg2\", \"-module(pg2). v() -> 1.\"), code:load_binary(pg2, \"pg2\", \"-module(pg2). v() -> 2.\"), code:purge(pg2)"))
+  "true")
+
+;; idempotent: purging again returns false (already purged)
+(er-eval-test "code:purge twice"
+  (nm (ev "code:load_binary(pg3, \"pg3\", \"-module(pg3). v() -> 1.\"), code:load_binary(pg3, \"pg3\", \"-module(pg3). v() -> 2.\"), code:purge(pg3), code:purge(pg3)"))
+  "false")
+
+;; purge returns true whenever an :old slot exists, regardless of process tracking
+;; (proper "kill lingering" semantics requires spawn/3 which is still stubbed)
+(er-eval-test "code:purge with old slot present"
+  (nm (ev "code:load_binary(pg4, \"pg4\", \"-module(pg4). loop() -> receive stop -> ok end.\"),
+           Pid = spawn(fun () -> pg4:loop() end),
+           code:load_binary(pg4, \"pg4\", \"-module(pg4). loop() -> receive stop -> done end.\"),
+           code:purge(pg4)"))
+  "true")
+
+;; soft_purge unknown → true (nothing to purge)
+(er-eval-test "code:soft_purge unknown"
+  (nm (ev "code:soft_purge(nope)")) "true")
+
+;; soft_purge with no old version → true
+(er-eval-test "code:soft_purge no old"
+  (nm (ev "code:load_binary(sp1, \"sp1\", \"-module(sp1). v() -> 1.\"), code:soft_purge(sp1)"))
+  "true")
+
+;; soft_purge with old + no lingering procs → true (clears :old)
+(er-eval-test "code:soft_purge clean"
+  (nm (ev "code:load_binary(sp2, \"sp2\", \"-module(sp2). v() -> 1.\"), code:load_binary(sp2, \"sp2\", \"-module(sp2). v() -> 2.\"), code:soft_purge(sp2)"))
+  "true")
+
+;; non-atom Mod is badarg (raise)
+(er-eval-test "code:purge badarg"
+  (nm (ev "try code:purge(\"str\") catch error:badarg -> ok end")) "ok")
+(er-eval-test "code:soft_purge badarg"
+  (nm (ev "try code:soft_purge(123) catch error:badarg -> ok end")) "ok")
+
 (define
   er-eval-test-summary
   (str "eval " er-eval-test-pass "/" er-eval-test-count))