Add console command

Console loads a new IRB session after loading the :default group, and
can optionally load another group that you pass as an argument, i.e.
`bundle console development`.

lib/bundler/cli.rb

@@ -190,6 +190,16 @@ def open(name)
       end
     end
 
+    desc "console [GROUP]", "Opens an IRB session with the bundle pre-loaded"
+    def console(group = nil)
+      require 'bundler/setup'
+      group ? Bundler.require(:default, group) : Bundler.require
+      ARGV.clear
+
+      require 'irb'
+      IRB.start
+    end
+
     desc "version", "Prints the bundler's version information"
     def version
       Bundler.ui.info "Bundler version #{Bundler::VERSION}"

spec/other/console_spec.rb

@@ -0,0 +1,102 @@
+require File.expand_path('../../spec_helper', __FILE__)
+
+describe "bundle console" do
+  before :each do
+    install_gemfile <<-G
+      source "file://#{gem_repo1}"
+      gem "rack"
+      gem "activesupport", :group => :test
+      gem "rack_middleware", :group => :development
+    G
+  end
+
+  it "starts IRB with the default group loaded" do
+    bundle "console" do |input|
+      input.puts("puts RACK")
+      input.puts("exit")
+    end
+    out.should include("0.9.1")
+  end
+
+  it "doesn't load any other groups" do
+    bundle "console" do |input|
+      input.puts("puts ACTIVESUPPORT")
+      input.puts("exit")
+    end
+    out.should include("NameError")
+  end
+
+  describe "when given a group" do
+    it "loads the given group" do
+      bundle "console test" do |input|
+        input.puts("puts ACTIVESUPPORT")
+        input.puts("exit")
+      end
+      out.should include("2.3.5")
+    end
+
+    it "loads the default group" do
+      bundle "console test" do |input|
+        input.puts("puts RACK")
+        input.puts("exit")
+      end
+      out.should include("0.9.1")
+    end
+
+    it "doesn't load other groups" do
+      bundle "console test" do |input|
+        input.puts("puts RACK_MIDDLEWARE")
+        input.puts("exit")
+      end
+      out.should include("NameError")
+    end
+  end
+
+  describe "when locked" do
+    before :each do
+      bundle :lock
+    end
+
+    it "starts IRB with the default group loaded" do
+      bundle :console do |input|
+        input.puts("puts RACK")
+        input.puts("exit")
+      end
+      out.should include("0.9.1")
+    end
+
+    it "doesn't load any other groups" do
+      bundle :console do |input|
+        input.puts("puts ACTIVESUPPORT")
+        input.puts("exit")
+      end
+      out.should include("NameError")
+    end
+
+    describe "and given a group" do
+      it "loads the given group" do
+        bundle "console test" do |input|
+          input.puts("puts ACTIVESUPPORT")
+          input.puts("exit")
+        end
+        out.should include("2.3.5")
+      end
+
+      it "loads the default group" do
+        bundle "console test" do |input|
+          input.puts("puts RACK")
+          input.puts("exit")
+        end
+        out.should include("0.9.1")
+      end
+
+      it "doesn't load other groups" do
+        bundle "console test" do |input|
+          input.puts("puts RACK_MIDDLEWARE")
+          input.puts("exit")
+        end
+        out.should include("NameError")
+      end
+    end
+  end
+end

spec/support/helpers.rb

@@ -42,11 +42,17 @@ def lib
     def bundle(cmd, options = {})
       expect_err = options.delete(:expect_err)
       exit_status = options.delete(:exit_status)
+
       env = (options.delete(:env) || {}).map{|k,v| "#{k}='#{v}' "}.join
       args = options.map { |k,v| " --#{k} #{v}"}.join
       gemfile = File.expand_path('../../../bin/bundle', __FILE__)
       cmd = "#{env}#{Gem.ruby} -I#{lib} #{gemfile} #{cmd}#{args}"
-      exit_status ? sys_status(cmd) : sys_exec(cmd, expect_err)
+
+      if exit_status
+        sys_status(cmd)
+      else
+        sys_exec(cmd, expect_err){|i| yield i if block_given? }
+      end
     end
 
     def ruby(ruby, options = {})
@@ -58,10 +64,14 @@ def ruby(ruby, options = {})
 
     def sys_exec(cmd, expect_err = false)
       require "open3"
-      input, out, err = Open3.popen3(cmd)
-      @err = err.read.strip
-      puts @err if !expect_err && $show_err && !@err.empty?
-      @out = out.read.strip
+      @in, @out, @err = Open3.popen3(cmd)
+
+      yield @in if block_given?
+
+      @err = err.read_available_bytes.strip
+      @out = out.read_available_bytes.strip
+
+      puts @err unless expect_err || @err.empty? || !$show_err
       @out
     end
 

spec/support/ruby_ext.rb

@@ -0,0 +1,15 @@
+class IO
+  def read_available_bytes(chunk_size = 1024, select_timeout = 5)
+    buffer = []
+
+    while self.class.select([self], nil, nil, select_timeout)
+      begin
+        buffer << self.readpartial(chunk_size)
+      rescue(EOFError)
+        break
+      end
+    end
+
+    return buffer.join
+  end
+end