diff --git a/Makefile b/Makefile
index aeaffae76..518110427 100644
--- a/Makefile
+++ b/Makefile
@@ -51,11 +51,9 @@ check: ## Run tests using the current binary executable build (meson/ninja)
 	ninja -C meson test
 
 check-js: ## Run tests using a wasm build for nodejs
-	yarn --cwd bindings/javascript
-	yarn --cwd bindings/javascript build
 	yarn --cwd bindings/javascript test
-	@echo "#!/bin/sh\nnode test/zenroom_exec.js src/zenroom.js \$$@\n" \
-		> test/zenroom && chmod +x test/zenroom
+	@sed 's@=ROOT=@'"${pwd}"'@' test/zexe_js_wrapper.sh > zenroom
+	@chmod +x zenroom
 
 install: destbin=${DESTDIR}${PREFIX}/bin
 install: destdocs=${DESTDIR}${PREFIX}/share/zenroom
diff --git a/test/zencode_exec.js b/test/zencode_exec.js
new file mode 100644
index 000000000..eaf5243e4
--- /dev/null
+++ b/test/zencode_exec.js
@@ -0,0 +1,40 @@
+const fs = require('fs')
+const util = require('util')
+
+const C = require(process.argv[2])() // 1st arg is path to WASM zenroom.js
+
+
+const zencodeExec = function(script, conf = null, keys = null, data = null) {
+  C.then(function(Module){
+	Module.exec_ok = () => 0
+	Module.exec_error = () => 0
+	Module.print = text => console.log(text)
+	Module.printErr = text => console.error(text)
+    Module.ccall(
+      'zencode_exec',
+      'number',
+      ['string', 'string', 'string', 'string', 'number'],
+      [script, conf, keys, data]
+    )
+  })
+}
+const zencode = function(script_file, conf_string=null, keys_file=null, data_file=null) {
+  const enc = { encoding: 'utf8' }
+  const script = fs.readFileSync(script_file, enc)
+  const conf = conf_string
+  const keys = (keys_file) ? fs.readFileSync(keys_file, enc) : null
+  const data = (data_file) ? fs.readFileSync(data_file, enc) : null
+  return zencodeExec(script, conf, keys, data)
+}
+
+// console.log("[JS] zenroom %s %s %s %s",
+//             process.argv[3], // script file
+//             process.argv[4], // conf string
+//             process.argv[5], // keys file
+//             process.argv[6], // data file
+// 		   )
+
+// console.time(process.argv[3])
+zencode(process.argv[3],process.argv[4],process.argv[5],process.argv[6])
+// console.timeEnd(process.argv[3])
+// console.log("@", "=".repeat(40), "@\n")
diff --git a/test/zenroom_exec.js b/test/zenroom_exec.js
index f1b8c4368..94a0d6c91 100644
--- a/test/zenroom_exec.js
+++ b/test/zenroom_exec.js
@@ -4,7 +4,7 @@ const util = require('util')
 // but it is not recommended as stated in https://github.com/kripken/emscripten/issues/2537
 // fs.writeFileSync('zenroom.js.mem', fs.readFileSync('src/zenroom.js.mem'));
 
-const C = require(process.argv[2])()
+const C = require(process.argv[2])() // 1st arg is path to WASM zenroom.js
 
 
 const zenroomExec = function(script, conf = null, keys = null, data = null) {
@@ -12,7 +12,7 @@ const zenroomExec = function(script, conf = null, keys = null, data = null) {
 	Module.exec_ok = () => 0
 	Module.exec_error = () => 0
 	Module.print = text => console.log(text)
-	Module.printErr = text => console.log(text)
+	Module.printErr = text => console.error(text)
     Module.ccall(
       'zenroom_exec',
       'number',
@@ -21,22 +21,23 @@ const zenroomExec = function(script, conf = null, keys = null, data = null) {
     )
   })
 }
-
-const zenroom = function(script_file, conf_file=null, keys_file=null, data_file=process.argv[4]) {
+const zenroom = function(script_file, conf_string=null, keys_file=null, data_file=null) {
   const enc = { encoding: 'utf8' }
   const script = fs.readFileSync(script_file, enc)
-  const conf = (conf_file) ? fs.readFileSync(conf_file, enc) : null
+  const conf = conf_string
   const keys = (keys_file) ? fs.readFileSync(keys_file, enc) : null
   const data = (data_file) ? fs.readFileSync(data_file, enc) : null
-
   return zenroomExec(script, conf, keys, data)
 }
 
-console.log("[JS] zenroom_exec %s %s",
-            process.argv[2],
-            process.argv[3])
+console.log("[JS] zenroom %s %s %s %s",
+            process.argv[3], // script file
+            process.argv[4], // conf string
+            process.argv[5], // keys file
+            process.argv[6], // data file
+		   )
 
 console.time(process.argv[3])
-zenroom(process.argv[3])
+zenroom(process.argv[3],process.argv[4],process.argv[5],process.argv[6])
 console.timeEnd(process.argv[3])
 console.log("@", "=".repeat(40), "@\n")
diff --git a/test/zexe_js_wrapper.sh b/test/zexe_js_wrapper.sh
new file mode 100644
index 000000000..280779b12
--- /dev/null
+++ b/test/zexe_js_wrapper.sh
@@ -0,0 +1,26 @@
+#!/bin/bash
+
+# template: %PATH% has to be subsituted with absolute path
+# this is processed by check-js to create a zenroom wrapper
+
+conf=${conf:-"logfmt=text,debug=0"}
+
+while getopts "zc:k:a:" arg; do
+  case $arg in
+    z) ;; # autodetected from script name
+	k) keys="${OPTARG}" ;;
+	a) data="${OPTARG}" ;;
+	c) conf="${OPTARG},logfmt=text,debug=0" ;;
+  esac
+done
+shift $((OPTIND-1))
+
+if [[ $1 == *.lua ]]; then
+	node =ROOT=/test/zenroom_exec.js \
+		 =ROOT=/bindings/javascript/dist/main/zenroom.js $1 $conf $keys $data
+elif [[ $1 == *.zen ]]; then
+	node =ROOT=/test/zencode_exec.js \
+		 =ROOT=/bindings/javascript/dist/main/zenroom.js $1 $conf $keys $data
+else
+	echo "Unsupported script: $1"
+fi