tweak: add an example showing the new conversion from/ToJS

Author: bobzhang

jscomp/test/build.ninja

@@ -494,6 +494,7 @@ build test/poly_variant_test.cmj : cc_cmi test/poly_variant_test.ml | test/mt.cm
 build test/poly_variant_test.cmi : cc test/poly_variant_test.mli | $stdlib
 build test/polymorphism_test.cmj : cc_cmi test/polymorphism_test.ml | test/polymorphism_test.cmi $stdlib
 build test/polymorphism_test.cmi : cc test/polymorphism_test.mli | $stdlib
+build test/polyvar_convert.cmi test/polyvar_convert.cmj : cc test/polyvar_convert.ml | $stdlib
 build test/polyvar_test.cmi test/polyvar_test.cmj : cc test/polyvar_test.ml | $stdlib
 build test/ppx_apply_test.cmi test/ppx_apply_test.cmj : cc test/ppx_apply_test.ml | test/mt.cmj $stdlib
 build test/ppx_this_obj_field.cmi test/ppx_this_obj_field.cmj : cc test/ppx_this_obj_field.ml | test/mt.cmj $stdlib

jscomp/test/debug_tmp.ml

@@ -5,7 +5,8 @@
   (* "-dlambda";  *)
   (* "-dtypedtree"; *)
   (* "-bs-diagnose" *)
-  
+  (* "-bs-diagnose"; *)
+  (* "-dsource"; *)
   |]
 }]
 

jscomp/test/polyvar_convert.js

@@ -0,0 +1,25 @@
+'use strict';
+
+
+var revData = {"x":"a","b":"b"};
+
+var data = {"a":"x","b":"b"};
+
+function tToJs(x) {
+  return data[x];
+}
+
+function vFromJsOpt(s) {
+  return revData[s];
+}
+
+function vFromJs(s) {
+  return revData[s];
+}
+
+exports.revData = revData;
+exports.data = data;
+exports.tToJs = tToJs;
+exports.vFromJsOpt = vFromJsOpt;
+exports.vFromJs = vFromJs;
+/* No side effect */

jscomp/test/polyvar_convert.ml

@@ -0,0 +1,17 @@
+type t = 
+  [ `a [@as "x"]
+  | `b ]
+
+
+let revData = [%raw {| {"x":"a","b":"b"} |}]  
+let data = [%raw {| {"a":"x","b":"b"} |}]  
+external get : 'a -> 'b -> 'c = "" [@@bs.get_index]
+
+let tToJs (x : t ) : string = 
+  get data x 
+
+let vFromJsOpt (s : string) : t option = 
+  get revData s 
+
+let vFromJs  (s : string) : t = 
+  get revData s