Merge pull request rescript-lang#2128 from BuckleScript/gpr_2126

fix rescript-lang#2126

Author: bobzhang

jscomp/runtime/caml_sys.ml

@@ -91,7 +91,9 @@ let caml_sys_get_argv () : string * string array =
   match [%external process] with 
   | None -> ("",[|""|])
   | Some process 
-    -> Array.unsafe_get process##argv 0, process##argv
+    -> 
+    if Js.testAny process##argv then ("",[|""|])
+    else Array.unsafe_get process##argv 0, process##argv
 
 (** {!Pervasives.sys_exit} *)
 let caml_sys_exit exit_code = 

jscomp/runtime/js.ml

@@ -63,6 +63,7 @@ type + 'a null_undefined = 'a nullable
 
 external toOption : 'a nullable  -> 'a option = "#null_undefined_to_opt"
 external test : 'a nullable -> bool = "#is_nil_undef"
+external testAny : 'a -> bool = "#is_nil_undef"
 
 type boolean
 (** The JS boolean type, can be [Js.true_] or [Js.false_] *)

jscomp/runtime/js.mli

@@ -76,6 +76,9 @@ type + 'a null_undefined = 'a nullable
 external toOption : 'a nullable  -> 'a option = "#null_undefined_to_opt"
 external test : 'a nullable -> bool = "#is_nil_undef"
 
+(** The same as {!test} except that it is more permissive on the types of input *)
+external testAny : 'a -> bool = "#is_nil_undef"
+
 type boolean
 (** The value could be either  {!Js.true_} or {!Js.false_}.
      Note in BuckleScript, [boolean] has different representation from OCaml's [bool],

jscomp/test/Makefile

@@ -198,7 +198,8 @@ OTHERS := test_literals a test_ari test_export2 test_internalOO test_obj_simple_
 	escape_esmodule\
 	esmodule_ref\
 	miss_colon_test\
-	gpr_1245_test
+	gpr_1245_test\
+	gpr_2126_test
 # bs_uncurry_test
 # needs Lam to get rid of Uncurry arity first
 

lib/js/caml_sys.js

@@ -45,10 +45,17 @@ function caml_sys_getcwd() {
 function caml_sys_get_argv() {
   var match = typeof (process) === "undefined" ? undefined : (process);
   if (match !== undefined) {
-    return /* tuple */[
-            match.argv[0],
-            match.argv
-          ];
+    if (match.argv == null) {
+      return /* tuple */[
+              "",
+              /* array */[""]
+            ];
+    } else {
+      return /* tuple */[
+              match.argv[0],
+              match.argv
+            ];
+    }
   } else {
     return /* tuple */[
             "",