erlang: echo.erl minimal server (+7 tests)

2026-04-25 00:00:47 +00:00
parent 8a8d0e14bd
commit 51ba2da119
2 changed files with 142 additions and 1 deletions
--- a/lib/erlang/tests/programs/echo.sx
+++ b/lib/erlang/tests/programs/echo.sx
@@ -0,0 +1,140 @@
+;; Echo server — minimal classic Erlang server. Receives {From, Msg}
+;; and sends Msg back to From, then loops. `stop` ends the server.
+
+(define er-echo-test-count 0)
+(define er-echo-test-pass 0)
+(define er-echo-test-fails (list))
+
+(define
+  er-echo-test
+  (fn
+    (name actual expected)
+    (set! er-echo-test-count (+ er-echo-test-count 1))
+    (if
+      (= actual expected)
+      (set! er-echo-test-pass (+ er-echo-test-pass 1))
+      (append! er-echo-test-fails {:actual actual :expected expected :name name}))))
+
+(define echo-ev erlang-eval-ast)
+
+(define
+  er-echo-server-src
+  "EchoSrv = fun () ->
+     Loop = fun () ->
+       receive
+         {From, Msg} -> From ! Msg, Loop();
+         stop -> ok
+       end
+     end,
+     Loop()
+   end")
+
+;; Single round-trip with an atom.
+(er-echo-test
+  "atom round-trip"
+  (get
+    (echo-ev
+      (str
+        er-echo-server-src
+        ", Me = self(),
+         Echo = spawn(EchoSrv),
+         Echo ! {Me, hello},
+         receive R -> Echo ! stop, R end"))
+    :name)
+  "hello")
+
+;; Number round-trip.
+(er-echo-test
+  "number round-trip"
+  (echo-ev
+    (str
+      er-echo-server-src
+      ", Me = self(),
+       Echo = spawn(EchoSrv),
+       Echo ! {Me, 42},
+       receive R -> Echo ! stop, R end"))
+  42)
+
+;; Tuple round-trip — pattern-match the reply to extract V.
+(er-echo-test
+  "tuple round-trip"
+  (echo-ev
+    (str
+      er-echo-server-src
+      ", Me = self(),
+       Echo = spawn(EchoSrv),
+       Echo ! {Me, {ok, 7}},
+       receive {ok, V} -> Echo ! stop, V end"))
+  7)
+
+;; List round-trip.
+(er-echo-test
+  "list round-trip"
+  (echo-ev
+    (str
+      er-echo-server-src
+      ", Me = self(),
+       Echo = spawn(EchoSrv),
+       Echo ! {Me, [1, 2, 3]},
+       receive [H | _] -> Echo ! stop, H end"))
+  1)
+
+;; Multiple sequential round-trips.
+(er-echo-test
+  "three round-trips"
+  (echo-ev
+    (str
+      er-echo-server-src
+      ", Me = self(),
+       Echo = spawn(EchoSrv),
+       Echo ! {Me, 10}, A = receive Ra -> Ra end,
+       Echo ! {Me, 20}, B = receive Rb -> Rb end,
+       Echo ! {Me, 30}, C = receive Rc -> Rc end,
+       Echo ! stop,
+       A + B + C"))
+  60)
+
+;; Two clients sharing one echo server. Each gets its own reply.
+(er-echo-test
+  "two clients"
+  (get
+    (echo-ev
+      (str
+        er-echo-server-src
+        ", Me = self(),
+         Echo = spawn(EchoSrv),
+         Client = fun (Tag) ->
+           spawn(fun () ->
+             Echo ! {self(), Tag},
+             receive R -> Me ! {got, R} end
+           end)
+         end,
+         Client(a),
+         Client(b),
+         receive {got, _} -> ok end,
+         receive {got, _} -> ok end,
+         Echo ! stop,
+         finished"))
+    :name)
+  "finished")
+
+;; Echo via io trace — verify each message round-trips through.
+(er-echo-test
+  "trace 4 messages"
+  (do
+    (er-io-flush!)
+    (echo-ev
+      (str
+        er-echo-server-src
+        ", Me = self(),
+         Echo = spawn(EchoSrv),
+         Send = fun (V) -> Echo ! {Me, V}, receive R -> io:format(\"~p \", [R]) end end,
+         Send(1), Send(2), Send(3), Send(4),
+         Echo ! stop,
+         done"))
+    (er-io-buffer-content))
+  "1 2 3 4 ")
+
+(define
+  er-echo-test-summary
+  (str "echo " er-echo-test-pass "/" er-echo-test-count))