Javascript code not working after upgrade to karate 0.9.3 - karate

Question

The below function in feature files was working for version 0.9.2. Upgraded to 0.9.3 and this gives error : javascript function call failed: Index: 0.0, Size: 0. Code below:
var cnd = ['test1','test2'];
function set_filter(arg)
{
var i;
var filter = {filterValues:[]};
for(i=0;i<arg.length;i++)
{
filter.filterValues[i] = arg[i];
}
return filter;
}
set_filter(cnd)
Also i was earlier able to push values in a javascript array using below, but this has also stopped working in 0.9.3. Get error:javascript function call failed: TypeError: arr.push is not a function
var arr = [];
arr.push('test1','test2');
Try the scenario below that works in 0.9.2 but reports error (mentioned above) in 0.9.3
Scenario: JS test
* def filter_template =
"""
function() {
var filter_params = {
filterValues:[]
};
return filter_params;
}
"""
* def template = call filter_template
* def filter_condition = ['test1','test2']
* def setFilter =
"""
function(arg) {
var i;
var filter = arg.filter_template;
for(i=0;i<arg.condition.length;i++)
{
filter.filterValues[i] = arg.condition[i];
}
return filter;
}
"""
* def getFilter = call setFilter { filter_template: '#(template)', condition: '#(filter_condition)' }
* print getFilter
Help is much appreciated.

Answer 1

We've made the JS conversions stricter, everything will be a Java collection behind the scenes. If you make this change, things will start working:
filter.filterValues.set(i, arg.condition.get(i));
The same goes for push() - use add() or karate.appendTo(varname, value) instead.
My strong recommendation is don't use too much of JS logic especially loops. Karate has functions such as map(), forEach() and repeat() to solve for these needs. Please refer the docs here: https://github.com/intuit/karate#loops
You will thank me later because it will make your scripts easier to understand and maintain. One reason why this is needed is to pave the way for us to change the JS engine in the future.