spurious singleton warning when using register_constant

[srenatus]

With r.rb as

require 'oso'

$polar=<<POLAR
test(b) if
  b = input.foo;
POLAR

input = {"foo" => "baz"}

o = Oso.new
o.load_str($polar)
o.register_constant('input', value: input)

x = Oso::Polar::Variable.new('x')
puts o.query_rule('test', x).force

I get the following output when running the script:

$ bundle exec ruby ../osoq/r.rb
Singleton variable input is unused or undefined, see <https://docs.oso.dev/using/polar-syntax.html#variables>
002:   b = input.foo;
           ^
{"x"=>"baz"}

It seems to work alright, but the warning is wrong?

[samscott89]

Hey @srenatus! Thanks for the report.

You're getting this warning because you're loading the rule before the constant is registered. If you swap those two lines the warning should go away.

[srenatus]

🤦 Of course. Thanks!