A minor issue with node-red 1.3.4, if the On Stop tab of a Function node consists of only comments (after the default header text there) then on passing the node a message the error
SyntaxError: Unexpected end of input (cleanup:line 17)
appears in the debug pane.
To replicate this add a new function node and add just a comment line to the On Stop tab, and feed it with an Inject node.
It may seem that this is a pointless thing to do, but it bit me when I was experimenting with On Stop code and commented it all out as a test. To get the node to run I had to completely delete the On Stop contents.