erlang: receive...after Ms timeout clause (+9 tests)

lib/erlang/tests/eval.sx

@@ -369,6 +369,37 @@
 (er-eval-test "receive nested tuple"
   (ev "Me = self(), Me ! {result, {ok, 42}}, receive {result, {ok, V}} -> V end") 42)
 
+;; ── receive ... after ... ───────────────────────────────────────
+(er-eval-test "after 0 empty mailbox"
+  (nm (ev "receive _ -> got after 0 -> timeout end"))
+  "timeout")
+(er-eval-test "after 0 match wins"
+  (nm (ev "Me = self(), Me ! ok, receive ok -> got after 0 -> timeout end"))
+  "got")
+(er-eval-test "after 0 non-match fires timeout"
+  (nm (ev "Me = self(), Me ! wrong, receive right -> got after 0 -> timeout end"))
+  "timeout")
+(er-eval-test "after 0 leaves non-match"
+  (ev "Me = self(), Me ! wrong, receive right -> got after 0 -> to end, receive X -> X end")
+  (er-mk-atom "wrong"))
+(er-eval-test "after Ms no sender — timeout fires"
+  (nm (ev "receive _ -> got after 100 -> timed_out end"))
+  "timed_out")
+(er-eval-test "after Ms with sender — match wins"
+  (nm (ev "Me = self(), spawn(fun () -> Me ! hi end), receive hi -> got after 100 -> to end"))
+  "got")
+(er-eval-test "after Ms computed"
+  (nm (ev "Ms = 50, receive _ -> got after Ms -> done end"))
+  "done")
+(er-eval-test "after 0 body side effect"
+  (do (er-io-flush!)
+    (ev "receive _ -> ok after 0 -> io:format(\"to~n\") end")
+    (er-io-buffer-content))
+  "to\n")
+(er-eval-test "after zero poll selective"
+  (ev "Me = self(), Me ! first, Me ! second, X = receive second -> got_second after 0 -> to end, Y = receive first -> got_first after 0 -> to end, {X, Y}")
+  (er-mk-tuple (list (er-mk-atom "got_second") (er-mk-atom "got_first"))))
+
 (define
   er-eval-test-summary
   (str "eval " er-eval-test-pass "/" er-eval-test-count))