FEAT: Check if activate is called as script. (#384)

Co-authored-by: Daniel <d.hornung@indiscale.com>

Author: quazgar

CHANGES

@@ -1,6 +1,11 @@
 Nodeenv changelog
 =================
 
+Version [unreleased]
+--------------------
+
+- Added check for how `activate` is called.
+
 Version 1.3.1
 -------------
 - Windows related fix `#207 <https://github.com/ekalinin/nodeenv/pull/207>`_

nodeenv.py

@@ -1342,6 +1342,16 @@ def main():
     fi
 }
 
+
+# Detect calling this file as a script
+case $0 in
+    */bin/activate )
+        echo "Do not call $0 directly.  Instead source it with \`source $0\`."
+        exit 1
+        ;;
+esac
+
+
 # unset irrelevant variables
 deactivate_node nondestructive