In a 'hexx-null' gem I have a file:
# lib/hexx/null.rb
module Hexx
class Null
# ...
end
end
The RSpec specification file is:
# spec/tests/null_spec.rb
describe Hexx::Null do
describe ".new" do
# ...
end
# ... etc.
end
Then I run the mutant from gem root:
$ mutant --include lib --require hexx-null --use rspec Hexx::Null
The result is:
Mutant configuration:
Matcher: #<Mutant::Matcher::Config match_expressions=[<Mutant::Expression: Hexx::Null>] subject_ignores=[] subject_selects=[]>
Integration: rspec
Expect Coverage: 100.00%
Jobs: 8
Includes: ["lib"]
Requires: ["hexx-null"]
Subjects: 0
Mutations: 0
Kills: 0
Alive: 0
Runtime: 0.05s
Killtime: 0.00s
Overhead: Inf%
Coverage: 0.00%
Expected: 100.00%
Active subjects: 0
It seems like mutant finds no examples, but why?