They are different code bases supported by different organizations. I would not expect them to stay in sync.
If you want to test grok filters then I would recommend that you do it using grok. Use two windows. In one run logstash with -r on the command line, so that it restarts the pipeline every time the configuration is modified. In the other edit the configuration. I would start with something like either
input { generator { count => 1 lines => [ '/list/Lighter-test-group/xyz/123', "/list" ] } }
filter {
grok { match => { "message" => "..." } }
}
output { stdout { codec => rubydebug { metadata => false } } }
or
input { file { path => "/home/foo.txt" sincedb_path => "/dev/null" start_position => beginning }
filter {
grok { match => { "message" => "..." } }
}
output { stdout { codec => rubydebug { metadata => false } } }