Remove unused 3rd arg from Cli::Main

features/lib/support/command_line.rb

@@ -85,7 +85,6 @@ def execute(args)
 
     Cucumber::Cli::Main.new(
       argument_list,
-      nil,
       @stdout,
       @stderr,
       @kernel
@@ -126,7 +125,6 @@ def execute(task)
       .and_wrap_original do |_, *args|
         Cucumber::Cli::Main.new(
           args[0],
-          nil,
           @stdout,
           @stderr,
           @kernel

lib/cucumber/cli/main.rb

@@ -14,12 +14,7 @@ def execute(args)
         end
       end
 
-      # The second argument is there for retrocompatibility
-      # Removing it will require a breaking change
-      # But it is actually responsible for a rubycop offense: too many optional parameters
-      # As we don't want to deactivate that cop globally, we disable it just for the
-      # following.
-      def initialize(args, _ = nil, out = $stdout, err = $stderr, kernel = Kernel) # rubocop:disable Metrics/ParameterLists
+      def initialize(args, out = $stdout, err = $stderr, kernel = Kernel)
         @args   = args
         @out    = out
         @err    = err

spec/cucumber/cli/main_spec.rb

@@ -12,11 +12,10 @@ module Cli
       end
 
       let(:args)   { [] }
-      let(:stdin)  { StringIO.new }
       let(:stdout) { StringIO.new }
       let(:stderr) { StringIO.new }
       let(:kernel) { double(:kernel) }
-      subject { Main.new(args, stdin, stdout, stderr, kernel) }
+      subject { Main.new(args, stdout, stderr, kernel) }
 
       describe '#execute!' do
         context 'passed an existing runtime' do