find-pattern.rb

#!/usr/bin/env ruby


installed = {
   mod_a: [ "1.0", "1.1", "1.2" ],
   mod_b: [ "1.2" ],
}


wanted_to_use = {
  mod_a: "1.1",
  mod_b: "1.1",
  mod_c: "1.2",
}


wanted_to_use.each do |mod, ver|
  case installed.to_a
  in [*, [^mod, [*, ^ver, *]], *]
    puts "#{mod} is installed and version matches"
  in [*, [^mod, _], *]
    puts "#{mod} is installed and version does not match"
  else
    puts "#{mod} is not installed"
  end
end

output

mod_a is installed and version matches
mod_b is installed and version does not match
mod_c is not installed