config: factor out control_d_handler to ControlDHandler

lib/pry.rb

@@ -23,6 +23,7 @@ require 'pry/history'
 require 'pry/color_printer'
 require 'pry/exception_handler'
 require 'pry/system_command_handler'
+require 'pry/control_d_handler'
 
 Pry::Commands = Pry::CommandSet.new unless defined?(Pry::Commands)
 

lib/pry/config.rb

@@ -51,27 +51,7 @@ class Pry
         should_load_requires: true,
         should_load_plugins: true,
         windows_console_warning: true,
-
-        # Deal with the ^D key being pressed. Different behaviour in different
-        # cases:
-        #   1. In an expression behave like `!` command.
-        #   2. At top-level session behave like `exit` command.
-        #   3. In a nested session behave like `cd ..`.
-        control_d_handler: proc do |eval_string, pry_instance|
-          if !eval_string.empty?
-            eval_string.replace('') # Clear input buffer.
-          elsif pry_instance.binding_stack.one?
-            pry_instance.binding_stack.clear
-            throw(:breakout)
-          else
-            # Otherwise, saves current binding stack as old stack and pops last
-            # binding out of binding stack (the old stack still has that binding).
-            pry_instance.command_state["cd"] ||= Pry::Config.from_hash({})
-            pry_instance.command_state['cd'].old_stack = pry_instance.binding_stack.dup
-            pry_instance.binding_stack.pop
-          end
-        end,
-
+        control_d_handler: Pry::ControlDHandler.method(:default),
         memory_size: 100,
         extra_sticky_locals: {},
         command_completions: proc { defaults.commands.keys },

lib/pry/control_d_handler.rb

@@ -0,0 +1,25 @@
+class Pry
+  # @api private
+  # @since ?.?.?
+  module ControlDHandler
+    # Deal with the ^D key being pressed. Different behaviour in different
+    # cases:
+    #   1. In an expression behave like `!` command.
+    #   2. At top-level session behave like `exit` command.
+    #   3. In a nested session behave like `cd ..`.
+    def self.default(eval_string, pry_instance)
+      if !eval_string.empty?
+        eval_string.replace('') # Clear input buffer.
+      elsif pry_instance.binding_stack.one?
+        pry_instance.binding_stack.clear
+        throw(:breakout)
+      else
+        # Otherwise, saves current binding stack as old stack and pops last
+        # binding out of binding stack (the old stack still has that binding).
+        pry_instance.command_state['cd'] ||= Pry::Config.from_hash({})
+        pry_instance.command_state['cd'].old_stack = pry_instance.binding_stack.dup
+        pry_instance.binding_stack.pop
+      end
+    end
+  end
+end

spec/control_d_handler_spec.rb

@@ -1,56 +1,49 @@
-describe 'Pry::Config.defaults.control_d_handler' do
-  describe "control-d press" do
-    before do
-      # Simulates a ^D press.
-      @control_d = "Pry::Config.defaults.control_d_handler.call('', pry_instance)"
+RSpec.describe Pry::ControlDHandler do
+  context "when given eval string is non-empty" do
+    let(:eval_string) { 'hello' }
+    let(:pry_instance) { Pry.new }
+
+    it "clears input buffer" do
+      described_class.default(eval_string, pry_instance)
+      expect(eval_string).to be_empty
+    end
+  end
+
+  context "when given eval string is empty & pry instance has one binding" do
+    let(:eval_string) { '' }
+    let(:pry_instance) { Pry.new.tap { |p| p.binding_stack = [binding] } }
+
+    it "throws :breakout" do
+      expect { described_class.default(eval_string, pry_instance) }
+        .to throw_symbol(:breakout)
     end
 
-    describe "in an expression" do
-      it "should clear out passed string" do
-        str = 'hello world'
-        Pry::Config.defaults.control_d_handler.call(str, nil)
-        expect(str).to eq ''
-      end
+    it "clears binding stack" do
+      expect { described_class.default(eval_string, pry_instance) }
+        .to throw_symbol
+      expect(pry_instance.binding_stack).to be_empty
+    end
+  end
+
+  context "when given eval string is empty & pry instance has 2+ bindings" do
+    let(:eval_string) { '' }
+    let(:binding1) { binding }
+    let(:binding2) { binding }
+    let(:binding_stack) { [binding1, binding2] }
+
+    let(:pry_instance) do
+      Pry.new.tap { |p| p.binding_stack = binding_stack }
     end
 
-    describe 'at top-level session' do
-      it 'should break out of a REPL loop' do
-        instance = Pry.new
-        expect(instance.binding_stack).not_to be_empty
-        expect(instance.eval(nil)).to equal false
-        expect(instance.binding_stack).to be_empty
-      end
+    it "saves a dup of the current binding stack in the 'cd' command" do
+      described_class.default(eval_string, pry_instance)
+      cd_state = pry_instance.command_state['cd']
+      expect(cd_state.old_stack).to eq([binding1, binding2])
     end
 
-    describe 'in a nested session' do
-      it 'should pop last binding from the binding stack' do
-        t = pry_tester
-        t.eval "cd Object.new"
-        expect(t.eval("pry_instance.binding_stack.size")).to eq 2
-        expect(t.eval("pry_instance.eval(nil)")).to equal true
-        expect(t.eval("pry_instance.binding_stack.size")).to eq 1
-      end
-
-      it "breaks out of the parent session" do
-        ReplTester.start do
-          input  'Pry::REPL.new(pry_instance, :target => 10).start'
-          output ''
-          prompt(/10.*> $/)
-
-          input  'self'
-          output '=> 10'
-
-          input  nil # Ctrl-D
-          output ''
-
-          input  'self'
-          output '=> main'
-
-          input  nil # Ctrl-D
-          output '=> nil' # Exit value of nested REPL.
-          assert_exited
-        end
-      end
+    it "pops the binding off the stack" do
+      described_class.default(eval_string, pry_instance)
+      expect(pry_instance.binding_stack).to eq([binding1])
     end
   end
 end