cli_spec: improve test coverage and refactor

57.14% is covered. We don't cover `on` switches because it's hard to
test them.

We also replace `exit` with `Kernel.exit` because this way we can mock this
method. Not sure why plain `exit` cannot be mocked.

lib/pry/cli.rb

@@ -80,7 +80,7 @@ class Pry
         rescue Pry::Slop::InvalidOptionError
           # Display help message on unknown switches and exit.
           puts Pry::Slop.new(&options)
-          exit
+          Kernel.exit
         end
 
         Pry.initial_session_setup
@@ -93,7 +93,7 @@ class Pry
       end
 
       def start(opts)
-        exit if opts.help?
+        Kernel.exit if opts.help?
 
         # invoked via cli
         Pry.cli = true
@@ -110,7 +110,7 @@ class Pry
         if !@pass_argv && Pry::CLI.input_args.any? && Pry::CLI.input_args != ["pry"]
           full_name = File.expand_path(Pry::CLI.input_args.first)
           Pry.load_file_through_repl(full_name)
-          exit
+          Kernel.exit
         end
 
         # Start the session (running any code passed with -e, if there is any)
@@ -182,7 +182,7 @@ Pry::CLI.add_options do
     Pry.locate_plugins.each do |plugin|
       puts plugin.name.to_s.ljust(18) << plugin.spec.summary
     end
-    exit
+    Kernel.exit
   end
 
   on "simple-prompt", "Enable simple prompt mode" do
@@ -214,7 +214,7 @@ Pry::CLI.add_options do
 
   on :v, :version, "Display the Pry version" do
     puts "Pry version #{Pry::VERSION} on Ruby #{RUBY_VERSION}"
-    exit
+    Kernel.exit
   end
 
   on :c, :context=,

spec/cli_spec.rb

@@ -1,85 +1,236 @@
 RSpec.describe Pry::CLI do
-  before do
-    Pry::CLI.reset
-  end
+  before { described_class.reset }
 
-  describe "parsing options" do
-    it 'should raise if no options defined' do
-      expect { Pry::CLI.parse_options(["--nothing"]) }
-        .to raise_error Pry::CLI::NoOptionsError
+  describe ".add_options" do
+    it "returns self" do
+      expect(described_class.add_options).to eq(described_class)
     end
 
-    it "should remove args from ARGV by default" do
-      argv = ['filename', '-v']
-      Pry::CLI.add_options do
-        on :v, "Display the Pry version" do
-          # irrelevant
-        end
-      end.parse_options(argv)
-      expect(argv.include?('-v')).to eq false
+    context "when options is nil and a block is provided" do
+      before { described_class.options = nil }
+
+      it "sets the block as options" do
+        block = proc {}
+        described_class.add_options(&block)
+        expect(described_class.options).to eql(block)
+      end
+    end
+
+    context "when options were previously set" do
+      it "overwrites the options proc that executes the provided block" do
+        described_class.options = proc {}
+
+        executed = false
+        described_class.add_options { executed = true }
+
+        described_class.options.call
+        expect(executed).to be_truthy
+      end
+
+      it "overwrites the options proc that executes original options" do
+        original_executed = false
+        described_class.options = proc { original_executed = true }
+
+        described_class.add_options {}
+        described_class.options.call
+
+        expect(original_executed).to be_truthy
+      end
     end
   end
 
-  describe "adding options" do
-    it "should be able to add an option" do
-      run = false
-
-      Pry::CLI.add_options do
-        on :optiontest, "A test option" do
-          run = true
-        end
-      end.parse_options(["--optiontest"])
-
-      expect(run).to eq true
+  describe ".add_plugin_options" do
+    it "returns self" do
+      expect(described_class.add_plugin_options).to eq(described_class)
     end
 
-    it "should be able to add multiple options" do
-      run = false
-      run2 = false
+    it "loads cli options of plugins" do
+      plugin_mock = double
+      expect(plugin_mock).to receive(:load_cli_options)
+      plugins = { 'pry-testplugin' => plugin_mock }
+      expect(Pry).to receive(:plugins).and_return(plugins)
 
-      Pry::CLI.add_options do
-        on :optiontest, "A test option" do
-          run = true
-        end
-      end.add_options do
-        on :optiontest2, "Another test option" do
-          run2 = true
-        end
-      end.parse_options(["--optiontest", "--optiontest2"])
-
-      expect(run).to equal true
-      expect(run2).to equal true
+      described_class.add_plugin_options
     end
   end
 
-  describe "processing options" do
-    it "should be able to process an option" do
-      run = false
-
-      Pry::CLI.add_options do
-        on :optiontest, "A test option"
-      end.add_option_processor do |opts|
-        run = true if opts.present?(:optiontest)
-      end.parse_options(["--optiontest"])
-
-      expect(run).to eq true
+  describe ".add_option_processor" do
+    it "returns self" do
+      expect(described_class.add_option_processor {}).to eq(described_class)
     end
 
-    it "should be able to  process multiple options" do
-      run = false
-      run2 = false
+    it "adds an option processor" do
+      option_processor = proc {}
+      described_class.add_option_processor(&option_processor)
+      expect(described_class.option_processors).to eql([option_processor])
+    end
+  end
 
-      Pry::CLI.add_options do
-        on :optiontest, "A test option"
-        on :optiontest2, "Another test option"
-      end.add_option_processor do |opts|
-        run = true if opts.present?(:optiontest)
-      end.add_option_processor do |opts|
-        run2 = true if opts.present?(:optiontest2)
-      end.parse_options(["--optiontest", "--optiontest2"])
+  describe ".parse_options" do
+    context "when option exists" do
+      before { described_class.options = proc { on(:v, 'test') } }
 
-      expect(run).to eq true
-      expect(run2).to eq true
+      it "removes the existing option from ARGV" do
+        argv = %w[filename -v]
+        described_class.parse_options(argv)
+        expect(argv).not_to include('-v')
+      end
+
+      it "initializes session setup" do
+        expect(Pry).to receive(:initial_session_setup)
+        described_class.parse_options(%w[-v])
+      end
+
+      it "finalizes session setup" do
+        expect(Pry).to receive(:final_session_setup)
+        described_class.parse_options(%w[-v])
+      end
+    end
+
+    context "when multiple options exist" do
+      it "processes only called options" do
+        processor_a_called = false
+        processor_b_called = false
+        processor_c_called = false
+        described_class.options = proc do
+          on('option-a', 'test a') { processor_a_called = true }
+          on('option-b', 'test b') { processor_b_called = true }
+          on('option-c', 'test c') { processor_c_called = true }
+        end
+
+        described_class.parse_options(%w[--option-a --option-b])
+
+        expect(processor_a_called).to be_truthy
+        expect(processor_b_called).to be_truthy
+        expect(processor_c_called).to be_falsey
+      end
+    end
+
+    context "when option doesn't exist" do
+      it "raises error" do
+        expect { described_class.parse_options(['--nothing']) }
+          .to raise_error(Pry::CLI::NoOptionsError)
+      end
+    end
+
+    context "when argv is passed with a dash (-)" do
+      before { described_class.options = proc {} }
+
+      it "sets everything after the dash as input args" do
+        argv = %w[filename - foo bar]
+        described_class.parse_options(argv)
+        expect(described_class.input_args).to eq(%w[foo bar])
+      end
+    end
+
+    context "when argv is passed with a double dash (--)" do
+      before { described_class.options = proc {} }
+
+      it "sets everything after the double dash as input args" do
+        argv = %w[filename -- foo bar]
+        described_class.parse_options(argv)
+        expect(described_class.input_args).to eq(%w[foo bar])
+      end
+    end
+
+    context "when invalid option is provided" do
+      before { described_class.options = proc { on(:valid, 'valid') } }
+
+      it "exits program" do
+        expect(Kernel).to receive(:exit)
+        expect(STDOUT).to receive(:puts)
+
+        described_class.parse_options(%w[--invalid])
+      end
+    end
+  end
+
+  describe ".start" do
+    before do
+      # Don't start Pry session in the middle of tests.
+      allow(Pry).to receive(:start)
+
+      described_class.options = proc {}
+    end
+
+    it "sets Pry.cli to true" do
+      opts = described_class.parse_options(%w[])
+      described_class.start(opts)
+      expect(Pry.cli).to be_truthy
+    end
+
+    context "when the help option is provided" do
+      before { described_class.options = proc { on(:help, 'help') } }
+
+      it "exits" do
+        expect(Kernel).to receive(:exit)
+
+        opts = described_class.parse_options(%w[--help])
+        described_class.start(opts)
+      end
+    end
+
+    context "when the context option is provided" do
+      before { described_class.options = proc { on(:context=, 'context') } }
+
+      it "initializes session setup" do
+        expect(Pry).to receive(:initial_session_setup).twice
+        opts = described_class.parse_options(%w[--context=Object])
+        described_class.start(opts)
+      end
+
+      it "finalizes session setup" do
+        expect(Pry).to receive(:final_session_setup).twice
+        opts = described_class.parse_options(%w[--context=Object])
+        described_class.start(opts)
+      end
+
+      it "starts Pry in the provided context" do
+        expect(Pry).to receive(:start).with(
+          instance_of(Binding), input: instance_of(StringIO)
+        ) do |binding, _opts|
+          expect(binding.eval('self')).to be_an(Object)
+        end
+        opts = described_class.parse_options(%w[--context=Object])
+        described_class.start(opts)
+      end
+    end
+
+    context "when the context option is not provided" do
+      before { described_class.options = proc {} }
+
+      it "starts Pry in the top level" do
+        expect(Pry).to receive(:start).with(
+          instance_of(Binding), input: instance_of(StringIO)
+        ) do |binding, _opts|
+          expect(binding.eval('self')).to eq(Pry.main)
+        end
+        opts = described_class.parse_options(%w[])
+        described_class.start(opts)
+      end
+    end
+
+    context "when there are some input args" do
+      before { described_class.options = proc {} }
+
+      it "loads files through repl and exits" do
+        expect(Pry).to receive(:load_file_through_repl).with(match(%r{pry/foo}))
+        expect(Kernel).to receive(:exit)
+
+        opts = described_class.parse_options(%w[foo])
+        described_class.start(opts)
+      end
+    end
+
+    context "when 'pry' is passed as an input arg" do
+      before { described_class.options = proc {} }
+
+      it "does not load files through repl" do
+        expect(Pry).not_to receive(:load_file_through_repl)
+
+        opts = described_class.parse_options(%w[pry])
+        described_class.start(opts)
+      end
     end
   end
 end