config: factor out 'system' to SystemCommandHandler

lib/pry.rb

@@ -22,6 +22,7 @@ require 'pry/editor'
 require 'pry/history'
 require 'pry/color_printer'
 require 'pry/exception_handler'
+require 'pry/system_command_handler'
 
 Pry::Commands = Pry::CommandSet.new unless defined?(Pry::Commands)
 

lib/pry/config.rb

@@ -34,14 +34,7 @@ class Pry
         # sessions.
         hooks: Pry::Hooks.default,
         pager: true,
-
-        system: proc do |output, cmd, _|
-          next if system(cmd)
-
-          output.puts 'Error: there was a problem executing system ' \
-                      "command: #{cmd}"
-        end,
-
+        system: Pry::SystemCommandHandler.method(:default),
         color: Pry::Helpers::BaseHelpers.use_ansi_codes?,
         default_window_size: 5,
         editor: Pry::Editor.default,

lib/pry/system_command_handler.rb

@@ -0,0 +1,15 @@
+class Pry
+  # @api private
+  # @since ?.?.?
+  module SystemCommandHandler
+    class << self
+      def default(output, command, _pry_instance)
+        return if Kernel.system(command)
+
+        output.puts(
+          "Error: there was a problem executing system command: #{command}"
+        )
+      end
+    end
+  end
+end

spec/system_command_handler_spec.rb

@@ -0,0 +1,34 @@
+require 'stringio'
+
+RSpec.describe Pry::SystemCommandHandler do
+  describe ".default" do
+    let(:output) { StringIO.new }
+    let(:pry_instance) { Pry.new }
+
+    before { allow(Kernel).to receive(:system) }
+
+    context "when command exists" do
+      before do
+        expect(Kernel).to receive(:system).with('test-command').and_return(true)
+      end
+
+      it "executes the command without printing the warning" do
+        described_class.default(output, 'test-command', pry_instance)
+        expect(output.string).to be_empty
+      end
+    end
+
+    context "when doesn't exist" do
+      before do
+        allow(Kernel).to receive(:system).with('test-command').and_return(nil)
+      end
+
+      it "executes the command without printing the warning" do
+        described_class.default(output, 'test-command', pry_instance)
+        expect(output.string).to eq(
+          "Error: there was a problem executing system command: test-command\n"
+        )
+      end
+    end
+  end
+end