Best way to test/debug javascript mappers/policies in Keycloak

Question

I am new to Keycloak and have been trying to setup javascript based authz policies and client mappers. I was wondering what is the best way to debug such mappers or policies.

Right now, if there are any errors within the script I can only find out it in the server logs, but is there a way where we can use something like alert or console.log; in both cases the server logs mentions:

Caused by: <eval>:18 ReferenceError: "alert" is not defined
Caused by: <eval>:18 ReferenceError: "console" is not defined 

It will be really helpful if when the script runs , if i can atleast log the values of properties or attributes to check whats going on

Answer 1

You can use

print("something");

you will see it in server logs

Answer 2

You can start KeyCloak with Debug-Option, e.g. with the following script

#!/bin/bash
echo "Starting KeyCloak"
sh ./keycloak-4.7.0.Final/bin/standalone.sh --debug 6666

I used this to debug my java-mappers and java-provider. Perhaps it can also help for javascript.