How to access Javascript function using JSR223 Sampler in JMeter? - jmeter

Question

I have a Javascript function in JSR223 Sampler and I would like to call this function in my HTTP Request sampler. Any idea how to call the function?
Example:
I know I can do something like this and use the "total" variable from my HTTP Request Sampler.
var total;
function sum(a, b){
return a+b;
};
vars.put("total", sum(2,4));
But is there a way to call the function sum(a,b) directly from HTTP Request sampler? If not, is there any other way to do this? A sample example will really help me a lot.

Answer 1

First of all, are you aware of __intSum() function which does exactly what you're trying to achieve, the syntax would be:
${__intSum(2,4,total)}
If you still want to proceed with coding:
Don't use JavaScript as it might become a performance bottleneck. Since JMeter 3.1 it is strongly recommended to use Groovy for scripting.
Create a file, i.e. sum.groovy in "bin" folder of your JMeter installation and put the following code into "Script" area:
int sum (int a, int b) {
return a + b;
}
Run JMeter as follows:
jmeter -Jgroovy.utilities=sum.groovy
If you want to make the change permanent - add the relevant line to user.properties file
groovy.utilities=sum.groovy
See Apache JMeter Properties Customization Guide for more detailed information on setting and overriding JMeter properties
You will be able to sum numbers with __groovy function like:
${__groovy(sum(2\, 4),total)}