From 95b1fe0776dd10b4e9f684ca2605c1898c0ca343 Mon Sep 17 00:00:00 2001
From: Hamdi Sahloul <hamdisahloul@hotmail.com>
Date: Thu, 20 Sep 2018 20:56:21 +0900
Subject: [PATCH] JS: Provides meaningful message in case of compile issues

---
 modules/js/src/make_umd.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/modules/js/src/make_umd.py b/modules/js/src/make_umd.py
index 4bca6c152b..7f7dffc880 100644
--- a/modules/js/src/make_umd.py
+++ b/modules/js/src/make_umd.py
@@ -103,4 +103,7 @@ if __name__ == "__main__":
     if len(sys.argv) > 2:
         opencvjs = sys.argv[1]
         cvjs = sys.argv[2]
+        if not os.path.isfile(opencvjs):
+            print('opencv.js file not found! Have you compiled the opencv_js module?')
+            exit()
         make_umd(opencvjs, cvjs);