demonstrate unsoundness with getSet

Author: anmonteiro

test/blackbox-tests/mel-unwrap-in-jsproperties.t

@@ -15,9 +15,18 @@ Tests for deriving `jsProperties, getSet`
   >   let t = t ~action:(\`String "hello") () in
   >   (* Set action and expect the value to be unwrapped in the object too *)
   >   actionSet t (\`String "hello2");
-  >   Js.log2 "Action after setting: " t
+  >   Js.log2 "Action after setting: " t;
+  >   (* Expect the value to be what we declared in the type, but it isn't *)
+  >   let action: [ \`String of string | \`Int of int ] option = actionGet t in
+  >   (* This is, therefore, unsound *)
+  >   match action with
+  >   | None -> ()
+  >   | Some (\`String s) ->
+  >     Js.log2 "action in t is string:" s;
+  >   | Some (\`Int i) ->
+  >     Js.log2 "action in t is int:" i;
   > EOF
-  $ melc -ppx melppx -dsource x.ml
+  $ melc -ppx melppx -dsource x.ml | tee x.js
   type t =
     {
     mutable action: [ `String of string  | `Int of int ] option
@@ -54,7 +63,15 @@ Tests for deriving `jsProperties, getSet`
     ((actionSet t (`String "hello2"))
     [@ocaml.warning "-ignored-extra-argument"]);
     ((Js.log2 "Action after setting: " t)
-    [@ocaml.warning "-ignored-extra-argument"])
+    [@ocaml.warning "-ignored-extra-argument"]);
+    (let action : [ `String of string  | `Int of int ] option = ((actionGet t)
+       [@ocaml.warning "-ignored-extra-argument"]) in
+     match action with
+     | None -> ()
+     | Some (`String s) -> ((Js.log2 "action in t is string:" s)
+         [@ocaml.warning "-ignored-extra-argument"])
+     | Some (`Int i) -> ((Js.log2 "action in t is int:" i)
+         [@ocaml.warning "-ignored-extra-argument"]))
   // Generated by Melange
   'use strict';
   
@@ -67,7 +84,18 @@ Tests for deriving `jsProperties, getSet`
   
   console.log("Action after setting: ", t);
   
+  const action = t.action;
+  
+  if (action !== undefined) {
+    if (action.NAME === "Int") {
+      console.log("action in t is int:", action.VAL);
+    } else {
+      console.log("action in t is string:", action.VAL);
+    }
+  }
+  
   /*  Not a pure module */
 
-
-
+  $ node x.js
+  Action after setting:  { action: 'hello2' }
+  action in t is string: undefined