Add integration tester, failing spec

spec/helper.rb

@@ -8,6 +8,7 @@ require 'mocha/api'
 require 'pry/test/helper'
 require 'helpers/bacon'
 require 'helpers/mock_pry'
+require 'helpers/repl_tester'
 
 class Module
   public :remove_const

spec/helpers/repl_tester.rb

@@ -0,0 +1,47 @@
+# This is for super-high-level integration testing.
+
+require 'fiber'
+
+class ReplTester
+  class Input
+    def readline(prompt)
+      Fiber.yield(prompt)
+    end
+  end
+
+  def self.start
+    redirect_pry_io Input.new, StringIO.new do
+      instance = new
+
+      yield instance
+      instance.in "exit-all"
+      raise "REPL didn't die" if instance.fiber.alive?
+    end
+  end
+
+  attr_accessor :pry, :repl, :fiber
+
+  def initialize
+    @pry   = Pry.new
+    @repl  = Pry::REPL.new(:pry => @pry)
+
+    @fiber = Fiber.new do
+      @repl.start
+    end
+
+    @fiber.resume
+  end
+
+  def in(input)
+    Pry.output.send(:initialize) # reset StringIO
+    @fiber.resume(input)
+  end
+
+  def prompt(match)
+    match.should === @pry.select_prompt
+  end
+
+  def out(match)
+    match.should === Pry.output.string.chomp
+  end
+end

spec/pry_repl_spec.rb

@@ -12,4 +12,21 @@ describe "The REPL" do
   it "should let you run commands in the middle of multiline expressions" do
     mock_pry("def a", "!", "5").should =~ /Input buffer cleared/
   end
+
+  it "shouldn't break if we start a nested session" do
+    ReplTester.start do |t|
+      t.in  'Pry::REPL.start(:pry => _pry_, :target => 10)'
+      t.out ''
+      t.prompt /10.*> $/
+
+      t.in  'self'
+      t.out '=> 10'
+
+      t.in  nil
+      t.out ''
+
+      t.in  'self'
+      t.out '=> main'
+    end
+  end
 end