Issue:
Using the JavaScript 'delete' function in the JavaScript processor does not work.
Cause:
This is due to the operation not being supported by the underlying Java script engine that is used to interpret and execute the JavaScript code.
Workaround:
If possible, try to use the Java interop that is available.
For example, if one were using the JavaScript 'delete' function to remove a field in a record map, you could use the fact that the Java map API is accessible as part of the interop.
E.g.
delete records[i].value['/a'];
can be done as follows:
records[i].value.remove('delete_this_field');