java coercion

* output_refactoring:
  Updated for JRuby
  Switch blue color to cyan for better contrast on dark terminals.
  80 char limit to end screen
  Updated Koans directory
  Added else clause if progress file is not there.
  regen for updated koans/edgecase.rb
  end screen with koans logo ascii art

Rakefile

@@ -11,18 +11,24 @@ DIST_DIR     = 'dist'
 SRC_FILES = FileList["#{SRC_DIR}/*"]
 KOAN_FILES = SRC_FILES.pathmap("#{PROB_DIR}/%f")
 
-TAR_FILE = "#{DIST_DIR}/rubykoans.tgz"
-ZIP_FILE = "#{DIST_DIR}/rubykoans.zip"
+today    = Time.now.strftime("%Y-%m-%d")
+TAR_FILE = "#{DIST_DIR}/rubykoans-#{today}.tgz"
+ZIP_FILE = "#{DIST_DIR}/rubykoans-#{today}.zip"
 
 CLOBBER.include(DIST_DIR)
 
 module Koans
+  # Remove solution info from source
+  #   __(a,b)     => __
+  #   _n_(number) => __
+  #   # __        =>
   def Koans.remove_solution(line)
     line = line.gsub(/\b____\([^\)]+\)/, "____")
     line = line.gsub(/\b___\([^\)]+\)/, "___")
     line = line.gsub(/\b__\([^\)]+\)/, "__")
     line = line.gsub(/\b_n_\([^\)]+\)/, "_n_")
     line = line.gsub(%r(/\#\{__\}/), "/__/")
+    line = line.gsub(/\s*#\s*__\s*$/, '')
     line
   end
 
@@ -83,14 +89,6 @@ task :upload => [TAR_FILE, ZIP_FILE] do
   sh "scp #{ZIP_FILE} linode:sites/onestepback.org/download"
 end
 
-desc "Check that the require files match the about_* files"
-task :check do
-  about_files = Dir['src/about_*.rb'].size
-  about_requires = `grep require src/path_to_enlightenment.rb | wc -l`.to_i
-  puts "# of about files:    #{about_files}"
-  puts "# of about requires: #{about_requires}"
-end
-
 desc "Generate the Koans from the source files from scratch."
 task :regen => [:clobber_koans, :gen]
 

koans/about_array_assignment.rb

@@ -18,13 +18,19 @@ class AboutArrayAssignment < EdgeCase::Koan
     assert_equal __, last_name
   end
 
-  def test_parallel_assignments_with_extra_variables
+  def test_parallel_assignments_with_splat_operator
+    first_name, *last_name = ["John", "Smith", "III"]
+    assert_equal __, first_name
+    assert_equal __, last_name
+  end
+
+  def test_parallel_assignments_with_too_few_variables
     first_name, last_name = ["Cher"]
     assert_equal __, first_name
     assert_equal __, last_name
   end
 
-  def test_parallel_assignements_with_subarrays
+  def test_parallel_assignments_with_subarrays
     first_name, last_name = [["Willie", "Rae"], "Johnson"]
     assert_equal __, first_name
     assert_equal __, last_name

koans/about_arrays.rb

@@ -3,7 +3,7 @@ require File.expand_path(File.dirname(__FILE__) + '/edgecase')
 class AboutArrays < EdgeCase::Koan
   def test_creating_arrays
     empty_array = Array.new
-    assert_equal Array, empty_array.class
+    assert_equal __, empty_array.class
     assert_equal __, empty_array.size
   end
 
@@ -45,9 +45,9 @@ class AboutArrays < EdgeCase::Koan
   end
 
   def test_arrays_and_ranges
-    assert_equal Range, (1..5).class
+    assert_equal __, (1..5).class
     assert_not_equal [1,2,3,4,5], (1..5)
-    assert_equal [1,2,3,4,5], (1..5).to_a
+    assert_equal __, (1..5).to_a
     assert_equal __, (1...5).to_a
   end
 

koans/about_classes.rb

@@ -130,7 +130,7 @@ class AboutClasses < EdgeCase::Koan
     fido = Dog6.new("Fido")
     rover = Dog6.new("Rover")
 
-    assert_not_equal rover.name, fido.name
+    assert_equal __, rover.name != fido.name
   end
 
   # ------------------------------------------------------------------
@@ -164,12 +164,12 @@ class AboutClasses < EdgeCase::Koan
 
   def test_to_s_provides_a_string_version_of_the_object
     fido = Dog7.new("Fido")
-    assert_equal "Fido", fido.to_s
+    assert_equal __, fido.to_s
   end
 
   def test_to_s_is_used_in_string_interpolation
     fido = Dog7.new("Fido")
-    assert_equal "My dog is Fido", "My dog is #{fido}"
+    assert_equal __, "My dog is #{fido}"
   end
 
   def test_inspect_provides_a_more_complete_string_version

koans/about_exceptions.rb

@@ -22,8 +22,8 @@ class AboutExceptions < EdgeCase::Koan
 
     assert_equal __, result
 
-    assert ex.is_a?(StandardError), "Failure message."
-    assert ex.is_a?(RuntimeError), "Failure message."
+    assert ex.is_a?(___), "Failure message."
+    assert ex.is_a?(___), "Failure message."
 
     assert RuntimeError.ancestors.include?(StandardError),
       "RuntimeError is a subclass of StandardError"
@@ -57,4 +57,12 @@ class AboutExceptions < EdgeCase::Koan
     assert_equal __, result
   end
 
+  # Sometimes, we must know about the unknown
+  def test_asserting_an_error_is_raised
+    # A do-end is a block, a topic to explore more later
+    assert_raise(___) do
+      raise MySpecialError.new("New instances can be raised directly.")
+    end
+  end
+
 end

koans/about_hashes.rb

@@ -3,7 +3,7 @@ require File.expand_path(File.dirname(__FILE__) + '/edgecase')
 class AboutHashes < EdgeCase::Koan
   def test_creating_hashes
     empty_hash = Hash.new
-    assert_equal Hash, empty_hash.class
+    assert_equal __, empty_hash.class
     assert_equal({}, empty_hash)
     assert_equal __, empty_hash.size
   end
@@ -25,7 +25,7 @@ class AboutHashes < EdgeCase::Koan
     hash[:one] = "eins"
 
     expected = { :one => __, :two => "dos" }
-    assert_equal expected, hash
+    assert_equal __, expected == hash
 
     # Bonus Question: Why was "expected" broken out into a variable
     # rather than used as a literal?
@@ -35,7 +35,7 @@ class AboutHashes < EdgeCase::Koan
     hash1 = { :one => "uno", :two => "dos" }
     hash2 = { :two => "dos", :one => "uno" }
 
-    assert_equal hash1, hash2
+    assert_equal __, hash1 == hash2
   end
 
   def test_hash_keys
@@ -43,7 +43,7 @@ class AboutHashes < EdgeCase::Koan
     assert_equal __, hash.keys.size
     assert_equal __, hash.keys.include?(:one)
     assert_equal __, hash.keys.include?(:two)
-    assert_equal Array, hash.keys.class
+    assert_equal __, hash.keys.class
   end
 
   def test_hash_values
@@ -51,16 +51,16 @@ class AboutHashes < EdgeCase::Koan
     assert_equal __, hash.values.size
     assert_equal __, hash.values.include?("uno")
     assert_equal __, hash.values.include?("dos")
-    assert_equal Array, hash.values.class
+    assert_equal __, hash.values.class
   end
 
   def test_combining_hashes
     hash = { "jim" => 53, "amy" => 20, "dan" => 23 }
     new_hash = hash.merge({ "jim" => 54, "jenny" => 26 })
 
-    assert_not_equal hash, new_hash
+    assert_equal __, hash != new_hash
 
     expected = { "jim" => __, "amy" => 20, "dan" => 23, "jenny" => __ }
-    assert_equal expected, new_hash
+    assert_equal __, expected == new_hash
   end
 end

koans/about_iteration.rb

@@ -12,7 +12,7 @@ class AboutIteration < EdgeCase::Koan
     array.each do |item|
       sum += item
     end
-    assert_equal 6, sum
+    assert_equal __, sum
   end
 
   def test_each_can_use_curly_brace_blocks_too

koans/about_java_interop.rb

@@ -0,0 +1,139 @@
+require File.expand_path(File.dirname(__FILE__) + '/edgecase')
+
+include Java
+
+# Concepts
+# * Pull in a java class
+# * calling a method, Camel vs snake
+# * Resovling module/class name conflicts
+# * Showing what gets returned
+# * Ruby Strings  VS Java Strings
+# * Calling custom java class
+# * Calling Ruby from java???
+
+class AboutJavaInterop < EdgeCase::Koan
+  def test_using_a_java_library_class
+    java_array = java.util.ArrayList.new
+    assert_equal __, java_array.class
+  end
+
+  def test_java_class_can_be_referenced_using_both_ruby_and_java_like_syntax
+    assert_equal __, Java::JavaUtil::ArrayList == java.util.ArrayList
+  end
+
+  def test_include_class_includes_class_in_module_scope
+    assert_nil defined?(TreeSet)
+    include_class "java.util.TreeSet"
+    assert_equal __, defined?(TreeSet)
+  end
+
+  # THINK ABOUT IT:
+  #
+  # What if we use:
+  #
+  #   include_class "java.lang.String"
+  #
+  # What would be the value of the String constant after this
+  # include_class is run?  Would it be useful to provide a way of
+  # aliasing java classes to different names?
+
+  JString = java.lang.String
+  def test_also_java_class_can_be_given_ruby_aliases
+    java_string = JString.new("A Java String")
+    assert_equal __, java_string.class
+    assert_equal __, JString
+  end
+
+  def test_can_directly_call_java_methods_on_java_objects
+    java_string = JString.new("A Java String")
+    assert_equal __, java_string.toLowerCase
+  end
+
+  def test_jruby_provides_snake_case_versions_of_java_methods
+    java_string = JString.new("A Java String")
+    assert_equal __, java_string.to_lower_case
+  end
+
+  def test_jruby_provides_question_mark_versions_of_boolean_methods
+    java_string = JString.new("A Java String")
+    assert_equal __, java_string.endsWith("String")
+    assert_equal __, java_string.ends_with("String")
+    assert_equal __, java_string.ends_with?("String")
+  end
+
+  def test_java_string_are_not_ruby_strings
+    ruby_string = "A Java String"
+    java_string = java.lang.String.new(ruby_string)
+    assert_equal __, java_string.is_a?(java.lang.String)
+    assert_equal __, java_string.is_a?(String)
+  end
+
+  def test_java_strings_can_be_compared_to_ruby_strings_maybe
+    ruby_string = "A Java String"
+    java_string = java.lang.String.new(ruby_string)
+    assert_equal __, ruby_string == java_string
+    assert_equal __, java_string == ruby_string
+
+    # THINK ABOUT IT:
+    #
+    # Is there any possible way for this to be more wrong?
+    #
+    # SERIOUSLY, THINK ABOUT IT:
+    #
+    # Why do you suppose that Ruby and Java strings compare like that?
+    #
+    # ADVANCED THINK ABOUT IT:
+    #
+    # Is there a way to make Ruby/Java string comparisons commutative?
+    # How would you do it?
+  end
+
+  def test_however_most_methods_returning_strings_return_ruby_strings
+    java_array = java.util.ArrayList.new
+    assert_equal __, java_array.toString
+    assert_equal __, java_array.toString.is_a?(String)
+    assert_equal __, java_array.toString.is_a?(java.lang.String)
+  end
+
+  def test_some_ruby_objects_can_be_coerced_to_java
+    assert_equal __, "ruby string".to_java.class
+    assert_equal __, 1.to_java.class
+    assert_equal __, 9.32.to_java.class
+    assert_equal __, false.to_java.class
+  end
+
+  def test_some_ruby_objects_can_NOT_be_coerced_to_java
+    [[], {}, Object.new].each do |ruby_object|
+      assert_raise(___) do
+        ruby_object.to_java_class
+      end
+    end
+  end
+
+  def test_java_collections_are_enumerable
+    java_array = java.util.ArrayList.new
+    java_array << "one" << "two" << "three"
+    assert_equal __, java_array.map { |item| item.upcase }
+  end
+
+  # ------------------------------------------------------------------
+
+  # Open the Java ArrayList class and add a new method.
+  class Java::JavaUtil::ArrayList
+    def multiply_all
+      result = 1
+      each do |item|
+        result *= item
+      end
+      result
+    end
+  end
+
+  def test_java_class_are_open_from_ruby
+    java_array = java.util.ArrayList.new
+    java_array.add_all([1,2,3,4,5])
+
+    assert_equal __, java_array.multiply_all
+  end
+
+end

koans/about_objects.rb

@@ -0,0 +1,56 @@
+require File.expand_path(File.dirname(__FILE__) + '/edgecase')
+
+class AboutObjects < EdgeCase::Koan
+  def test_everything_is_an_object
+    assert_equal __, 1.is_a?(Object)
+    assert_equal __, 1.5.is_a?(Object)
+    assert_equal __, "string".is_a?(Object)
+    assert_equal __, nil.is_a?(Object)
+    assert_equal __, Object.is_a?(Object)
+  end
+
+  def test_objects_can_be_converted_to_strings
+    assert_equal __, 123.to_s
+    assert_equal __, nil.to_s
+  end
+
+  def test_objects_can_be_inspected
+    assert_equal __, 123.inspect
+    assert_equal __, nil.inspect
+  end
+
+  def test_every_object_has_an_id
+    obj = Object.new
+    assert_equal __, obj.object_id.class
+  end
+
+  def test_every_object_has_different_id
+    obj = Object.new
+    another_obj = Object.new
+    assert_equal __, obj.object_id != another_obj.object_id
+  end
+
+  def test_some_system_objects_always_have_the_same_id
+    assert_equal __, false.object_id
+    assert_equal __, true.object_id
+    assert_equal __, nil.object_id
+  end
+
+  def test_small_integers_have_fixed_ids
+    assert_equal __, 0.object_id
+    assert_equal __, 1.object_id
+    assert_equal __, 2.object_id
+    assert_equal __, 100.object_id
+
+    # THINK ABOUT IT:
+    # What pattern do the object IDs for small integers follow?
+  end
+
+  def test_clone_creates_a_different_object
+    obj = Object.new
+    copy = obj.clone
+
+    assert_equal __, obj           != copy
+    assert_equal __, obj.object_id != copy.object_id
+  end
+end

koans/about_regular_expressions.rb

@@ -3,11 +3,11 @@ require File.expand_path(File.dirname(__FILE__) + '/edgecase')
 
 class AboutRegularExpressions < EdgeCase::Koan
   def test_a_pattern_is_a_regular_expression
-    assert_equal Regexp, /pattern/.class
+    assert_equal __, /pattern/.class
   end
 
   def test_a_regexp_can_search_a_string_for_matching_content
-    assert_equal "match", "some matching content"[/match/]
+    assert_equal __, "some matching content"[/match/]
   end
 
   def test_a_failed_match_returns_nil

koans/about_scope.rb

@@ -29,8 +29,8 @@ class AboutScope < EdgeCase::Koan
     assert_equal __, fido.identify
     assert_equal __, rover.identify
 
-    assert_not_equal fido.class, rover.class
-    assert_not_equal Jims::Dog, Joes::Dog
+    assert_equal __, fido.class != rover.class
+    assert_equal __, Jims::Dog != Joes::Dog
   end
 
   # ------------------------------------------------------------------

koans/about_strings.rb

@@ -182,4 +182,12 @@ EOS
     words = ["Now", "is", "the", "time"]
     assert_equal __, words.join(" ")
   end
+
+  def test_strings_are_not_unique_objects
+    a = "a string"
+    b = "a string"
+
+    assert_equal __, a           == b
+    assert_equal __, a.object_id == b.object_id
+  end
 end

koans/about_symbols.rb

@@ -19,21 +19,27 @@ class AboutSymbols < EdgeCase::Koan
     symbol1 = :a_symbol
     symbol2 = :a_symbol
 
-    assert symbol1.equal?(__)
-    assert_equal __, symbol2.object_id
+    assert_equal __, symbol1           == symbol2
+    assert_equal __, symbol1.object_id == symbol2.object_id
   end
 
   def test_method_names_become_symbols
     all_symbols = Symbol.all_symbols
-
-    assert_equal __, all_symbols.include?(:test_method_names_are_symbols)
+    assert_equal __, all_symbols.include?(:test_method_names_become_symbols)
   end
 
-  RubyConstant = "What is the sound of one hand clapping?"
-  def test_constants_become_symbols
-    all_symbols = Symbol.all_symbols
+  # THINK ABOUT IT:
+  #
+  # Why do we capture the list of symbols before we check for the
+  # method name?
 
-    assert_equal true, all_symbols.include?(__)
+  in_ruby_version("mri") do
+    RubyConstant = "What is the sound of one hand clapping?"
+    def test_constants_become_symbols
+      all_symbols = Symbol.all_symbols
+
+      assert_equal __, all_symbols.include?(__)
+    end
   end
 
   def test_symbols_can_be_made_from_strings
@@ -47,6 +53,13 @@ class AboutSymbols < EdgeCase::Koan
     assert_equal symbol, __.to_sym
   end
 
+  def test_symbols_with_spaces_can_be_built
+    value = "and"
+    symbol = :"cats #{value} dogs"
+
+    assert_equal symbol, __.to_sym
+  end
+
   def test_to_s_is_called_on_interpolated_symbols
     symbol = :cats
     string = "It is raining #{symbol} and dogs."
@@ -65,13 +78,23 @@ class AboutSymbols < EdgeCase::Koan
     assert_equal __, symbol.respond_to?(:each_char)
     assert_equal __, symbol.respond_to?(:reverse)
   end
+
   # It's important to realize that symbols are not "immutable
   # strings", though they are immutable. None of the
   # interesting string operations are available on symbols.
+
   def test_symbols_cannot_be_concatenated
     # Exceptions will be pondered further father down the path
     assert_raise(___) do
       :cats + :dogs
     end
   end
+
+  def test_symbols_can_be_dynamically_created
+    assert_equal __, ("cats" + "dogs").to_sym
+  end
+
+  # THINK ABOUT IT:
+  #
+  # Why is it not a good idea to dynamically create a lot of symbols?
 end

koans/edgecase.rb

@@ -3,13 +3,25 @@
 
 require 'test/unit/assertions'
 
+# --------------------------------------------------------------------
+# Support code for the Ruby Koans.
+# --------------------------------------------------------------------
+
 class FillMeInError < StandardError
 end
 
-def in_ruby_version(version)
-  yield if RUBY_VERSION =~ /^#{version}/
+def ruby_version?(version)
+  RUBY_VERSION =~ /^#{version}/ ||
+    (version == 'jruby' && defined?(JRUBY_VERSION)) ||
+    (version == 'mri' && ! defined?(JRUBY_VERSION))
 end
 
+def in_ruby_version(*versions)
+  yield if versions.any? { |v| ruby_version?(v) }
+end
+
+# Standard, generic replacement value.
+# If value19 is given, it is used inplace of value for Ruby 1.9.
 def __(value="FILL ME IN", value19=:mu)
   if RUBY_VERSION < "1.9"
     value
@@ -18,6 +30,7 @@ def __(value="FILL ME IN", value19=:mu)
   end
 end
 
+# Numeric replacement value.
 def _n_(value=999999, value19=:mu)
   if RUBY_VERSION < "1.9"
     value
@@ -26,10 +39,12 @@ def _n_(value=999999, value19=:mu)
   end
 end
 
+# Error object replacement value.
 def ___(value=FillMeInError)
   value
 end
 
+# Method name replacement.
 class Object
   def ____(method=nil)
     if method
@@ -42,7 +57,25 @@ class Object
   end
 end
 
+class String
+  def side_padding(width)
+    extra = width - self.size
+    if width < 0
+      self
+    else
+      left_padding = extra / 2
+      right_padding = (extra+1)/2
+      (" " * left_padding) + self + (" " *right_padding)
+    end
+  end
+end
+
 module EdgeCase
+  class << self
+    def simple_output
+      ENV['SIMPLE_KOAN_OUTPUT'] == 'true'
+    end
+  end
 
   module Color
     #shamelessly stolen (and modified) from redgreen
@@ -170,6 +203,21 @@ module EdgeCase
     end
 
     def end_screen
+      if EdgeCase.simple_output
+        boring_end_screen
+      else
+        artistic_end_screen
+      end
+    end
+
+    def boring_end_screen
+      puts "Mountains are again merely mountains"
+    end
+
+    def artistic_end_screen
+      "JRuby 1.9.x Koans"
+      ruby_version = "(in #{'J' if defined?(JRUBY_VERSION)}Ruby #{defined?(JRUBY_VERSION) ? JRUBY_VERSION : RUBY_VERSION})"
+      ruby_version = ruby_version.side_padding(54)
         completed = <<-ENDTEXT
                                   ,,   ,  ,,
                                 :      ::::,    :::,
@@ -186,8 +234,8 @@ module EdgeCase
  ,:::::::::::,                                                    ::::::::::::,
  :::::::::::,                                                     ,::::::::::::
 :::::::::::::                                                     ,::::::::::::
-::::::::::::                       Ruby Koans                      ::::::::::::,
-::::::::::::                                                      ,::::::::::::,
+::::::::::::                      Ruby Koans                       ::::::::::::,
+::::::::::::#{                  ruby_version                     },::::::::::::,
 :::::::::::,                                                      , ::::::::::::
 ,:::::::::::::,                brought to you by                 ,,::::::::::::,
 ::::::::::::::                                                    ,::::::::::::
@@ -248,12 +296,13 @@ ENDTEXT
     end
 
     def indent(text)
+      text = text.split(/\n/) if text.is_a?(String)
       text.collect{|t| "  #{t}"}
     end
 
     def find_interesting_lines(backtrace)
       backtrace.reject { |line|
-        line =~ /test\/unit\/|edgecase\.rb/
+        line =~ /test\/unit\/|edgecase\.rb|minitest/
       }
     end
 

koans/path_to_enlightenment.rb

@@ -4,6 +4,7 @@ $LOAD_PATH << File.dirname(__FILE__)
 
 require 'about_asserts'
 require 'about_nil'
+require 'about_objects'
 require 'about_arrays'
 require 'about_array_assignment'
 require 'about_hashes'
@@ -30,4 +31,7 @@ require 'about_scope'
 require 'about_class_methods'
 require 'about_message_passing'
 require 'about_proxy_object_project'
+in_ruby_version("jruby") do
+  require 'about_java_interop'
+end
 require 'about_extra_credit'

rakelib/checks.rake

@@ -0,0 +1,33 @@
+namespace "check" do
+
+  desc "Check that the require files match the about_* files"
+  task :abouts do
+    about_files = Dir['src/about_*.rb'].size
+    about_requires = `grep require src/path_to_enlightenment.rb | wc -l`.to_i
+    puts "Checking path_to_enlightenment completeness"
+    puts "# of about files:    #{about_files}"
+    puts "# of about requires: #{about_requires}"
+    if about_files > about_requires
+      puts "*** There seems to be requires missing in the path to enlightenment"
+    else
+      puts "OK"
+    end
+    puts
+  end
+
+  desc "Check that asserts have __ replacements"
+  task :asserts do
+    puts "Checking for asserts missing the replacement text:"
+    begin
+      sh "egrep -n 'assert( |_)' src/about_* | egrep -v '__|_n_|project|about_assert' | egrep -v ' *#'"
+      puts
+      puts "Examine the above lines for missing __ replacements"
+    rescue RuntimeError => ex
+      puts "OK"
+    end
+    puts
+  end
+end
+
+desc "Run some simple consistancy checks"
+task :check => ["check:abouts", "check:asserts"]

rakelib/run.rake

@@ -0,0 +1,8 @@
+RUBIES = ENV['KOAN_RUBIES'] || %w(ruby-1.8.7-p299,ruby-1.9.2-p0,jruby-1.5.2,jruby-head)
+
+task :runall do
+  chdir('src') do
+    ENV['SIMPLE_KOAN_OUTPUT'] = 'true'
+    sh "rvm #{RUBIES} path_to_enlightenment.rb"
+  end
+end

src/about_array_assignment.rb

@@ -18,13 +18,19 @@ class AboutArrayAssignment < EdgeCase::Koan
     assert_equal __("Smith"), last_name
   end
 
-  def test_parallel_assignments_with_extra_variables
+  def test_parallel_assignments_with_splat_operator
+    first_name, *last_name = ["John", "Smith", "III"]
+    assert_equal __("John"), first_name
+    assert_equal __(["Smith","III"]), last_name
+  end
+
+  def test_parallel_assignments_with_too_few_variables
     first_name, last_name = ["Cher"]
     assert_equal __("Cher"), first_name
     assert_equal __(nil), last_name
   end
 
-  def test_parallel_assignements_with_subarrays
+  def test_parallel_assignments_with_subarrays
     first_name, last_name = [["Willie", "Rae"], "Johnson"]
     assert_equal __(["Willie", "Rae"]), first_name
     assert_equal __("Johnson"), last_name

src/about_arrays.rb

@@ -3,16 +3,16 @@ require File.expand_path(File.dirname(__FILE__) + '/edgecase')
 class AboutArrays < EdgeCase::Koan
   def test_creating_arrays
     empty_array = Array.new
-    assert_equal Array, empty_array.class
+    assert_equal __(Array), empty_array.class
     assert_equal __(0), empty_array.size
   end
 
   def test_array_literals
     array = Array.new
-    assert_equal [], array
+    assert_equal [], array # __
 
     array[0] = 1
-    assert_equal [1], array
+    assert_equal [1], array     # __
 
     array[1] = 2
     assert_equal [1, __(2)], array
@@ -45,9 +45,9 @@ class AboutArrays < EdgeCase::Koan
   end
 
   def test_arrays_and_ranges
-    assert_equal Range, (1..5).class
-    assert_not_equal [1,2,3,4,5], (1..5)
-    assert_equal [1,2,3,4,5], (1..5).to_a
+    assert_equal __(Range), (1..5).class
+    assert_not_equal [1,2,3,4,5], (1..5) # __
+    assert_equal __([1,2,3,4,5]), (1..5).to_a
     assert_equal __([1,2,3,4]), (1...5).to_a
   end
 

src/about_classes.rb

@@ -130,7 +130,7 @@ class AboutClasses < EdgeCase::Koan
     fido = Dog6.new("Fido")
     rover = Dog6.new("Rover")
 
-    assert_not_equal rover.name, fido.name
+    assert_equal __(true), rover.name != fido.name
   end
 
   # ------------------------------------------------------------------
@@ -164,12 +164,12 @@ class AboutClasses < EdgeCase::Koan
 
   def test_to_s_provides_a_string_version_of_the_object
     fido = Dog7.new("Fido")
-    assert_equal "Fido", fido.to_s
+    assert_equal __("Fido"), fido.to_s
   end
 
   def test_to_s_is_used_in_string_interpolation
     fido = Dog7.new("Fido")
-    assert_equal "My dog is Fido", "My dog is #{fido}"
+    assert_equal __("My dog is Fido"), "My dog is #{fido}"
   end
 
   def test_inspect_provides_a_more_complete_string_version

src/about_exceptions.rb

@@ -22,10 +22,10 @@ class AboutExceptions < EdgeCase::Koan
 
     assert_equal __(:exception_handled), result
 
-    assert ex.is_a?(StandardError), "Failure message."
-    assert ex.is_a?(RuntimeError), "Failure message."
+    assert ex.is_a?(___(StandardError)), "Failure message."
+    assert ex.is_a?(___(RuntimeError)), "Failure message."
 
-    assert RuntimeError.ancestors.include?(StandardError),
+    assert RuntimeError.ancestors.include?(StandardError), # __
       "RuntimeError is a subclass of StandardError"
 
     assert_equal __("Oops"), ex.message
@@ -57,4 +57,12 @@ class AboutExceptions < EdgeCase::Koan
     assert_equal __(:always_run), result
   end
 
+  # Sometimes, we must know about the unknown
+  def test_asserting_an_error_is_raised # __
+    # A do-end is a block, a topic to explore more later
+    assert_raise(___(MySpecialError)) do
+      raise MySpecialError.new("New instances can be raised directly.")
+    end
+  end
+
 end

src/about_hashes.rb

@@ -3,8 +3,8 @@ require File.expand_path(File.dirname(__FILE__) + '/edgecase')
 class AboutHashes < EdgeCase::Koan
   def test_creating_hashes
     empty_hash = Hash.new
-    assert_equal Hash, empty_hash.class
-    assert_equal({}, empty_hash)
+    assert_equal __(Hash), empty_hash.class
+    assert_equal({}, empty_hash) # __
     assert_equal __(0), empty_hash.size
   end
 
@@ -25,7 +25,7 @@ class AboutHashes < EdgeCase::Koan
     hash[:one] = "eins"
 
     expected = { :one => __("eins"), :two => "dos" }
-    assert_equal expected, hash
+    assert_equal __(true), expected == hash
 
     # Bonus Question: Why was "expected" broken out into a variable
     # rather than used as a literal?
@@ -35,7 +35,7 @@ class AboutHashes < EdgeCase::Koan
     hash1 = { :one => "uno", :two => "dos" }
     hash2 = { :two => "dos", :one => "uno" }
 
-    assert_equal hash1, hash2
+    assert_equal __(true), hash1 == hash2
   end
 
   def test_hash_keys
@@ -43,7 +43,7 @@ class AboutHashes < EdgeCase::Koan
     assert_equal __(2), hash.keys.size
     assert_equal __(true), hash.keys.include?(:one)
     assert_equal __(true), hash.keys.include?(:two)
-    assert_equal Array, hash.keys.class
+    assert_equal __(Array), hash.keys.class
   end
 
   def test_hash_values
@@ -51,16 +51,16 @@ class AboutHashes < EdgeCase::Koan
     assert_equal __(2), hash.values.size
     assert_equal __(true), hash.values.include?("uno")
     assert_equal __(true), hash.values.include?("dos")
-    assert_equal Array, hash.values.class
+    assert_equal __(Array), hash.values.class
   end
 
   def test_combining_hashes
     hash = { "jim" => 53, "amy" => 20, "dan" => 23 }
     new_hash = hash.merge({ "jim" => 54, "jenny" => 26 })
 
-    assert_not_equal hash, new_hash
+    assert_equal __(true), hash != new_hash
 
     expected = { "jim" => __(54), "amy" => 20, "dan" => 23, "jenny" => __(26) }
-    assert_equal expected, new_hash
+    assert_equal __(true), expected == new_hash
   end
 end

src/about_iteration.rb

@@ -12,7 +12,7 @@ class AboutIteration < EdgeCase::Koan
     array.each do |item|
       sum += item
     end
-    assert_equal 6, sum
+    assert_equal __(6), sum
   end
 
   def test_each_can_use_curly_brace_blocks_too

src/about_java_interop.rb

@@ -0,0 +1,139 @@
+require File.expand_path(File.dirname(__FILE__) + '/edgecase')
+
+include Java
+
+# Concepts
+# * Pull in a java class
+# * calling a method, Camel vs snake
+# * Resovling module/class name conflicts
+# * Showing what gets returned
+# * Ruby Strings  VS Java Strings
+# * Calling custom java class
+# * Calling Ruby from java???
+
+class AboutJavaInterop < EdgeCase::Koan
+  def test_using_a_java_library_class
+    java_array = java.util.ArrayList.new
+    assert_equal __(Java::JavaUtil::ArrayList), java_array.class
+  end
+
+  def test_java_class_can_be_referenced_using_both_ruby_and_java_like_syntax
+    assert_equal __(true), Java::JavaUtil::ArrayList == java.util.ArrayList
+  end
+
+  def test_include_class_includes_class_in_module_scope
+    assert_nil defined?(TreeSet) # __
+    include_class "java.util.TreeSet"
+    assert_equal __("constant"), defined?(TreeSet)
+  end
+
+  # THINK ABOUT IT:
+  #
+  # What if we use:
+  #
+  #   include_class "java.lang.String"
+  #
+  # What would be the value of the String constant after this
+  # include_class is run?  Would it be useful to provide a way of
+  # aliasing java classes to different names?
+
+  JString = java.lang.String
+  def test_also_java_class_can_be_given_ruby_aliases
+    java_string = JString.new("A Java String")
+    assert_equal __(java.lang.String), java_string.class
+    assert_equal __(java.lang.String), JString
+  end
+
+  def test_can_directly_call_java_methods_on_java_objects
+    java_string = JString.new("A Java String")
+    assert_equal __("a java string"), java_string.toLowerCase
+  end
+
+  def test_jruby_provides_snake_case_versions_of_java_methods
+    java_string = JString.new("A Java String")
+    assert_equal __("a java string"), java_string.to_lower_case
+  end
+
+  def test_jruby_provides_question_mark_versions_of_boolean_methods
+    java_string = JString.new("A Java String")
+    assert_equal __(true), java_string.endsWith("String")
+    assert_equal __(true), java_string.ends_with("String")
+    assert_equal __(true), java_string.ends_with?("String")
+  end
+
+  def test_java_string_are_not_ruby_strings
+    ruby_string = "A Java String"
+    java_string = java.lang.String.new(ruby_string)
+    assert_equal __(true), java_string.is_a?(java.lang.String)
+    assert_equal __(false), java_string.is_a?(String)
+  end
+
+  def test_java_strings_can_be_compared_to_ruby_strings_maybe
+    ruby_string = "A Java String"
+    java_string = java.lang.String.new(ruby_string)
+    assert_equal __(false), ruby_string == java_string
+    assert_equal __(true), java_string == ruby_string
+
+    # THINK ABOUT IT:
+    #
+    # Is there any possible way for this to be more wrong?
+    #
+    # SERIOUSLY, THINK ABOUT IT:
+    #
+    # Why do you suppose that Ruby and Java strings compare like that?
+    #
+    # ADVANCED THINK ABOUT IT:
+    #
+    # Is there a way to make Ruby/Java string comparisons commutative?
+    # How would you do it?
+  end
+
+  def test_however_most_methods_returning_strings_return_ruby_strings
+    java_array = java.util.ArrayList.new
+    assert_equal __("[]"), java_array.toString
+    assert_equal __(true), java_array.toString.is_a?(String)
+    assert_equal __(false), java_array.toString.is_a?(java.lang.String)
+  end
+
+  def test_some_ruby_objects_can_be_coerced_to_java
+    assert_equal __(Java::JavaLang::String), "ruby string".to_java.class
+    assert_equal __(Java::JavaLang::Long), 1.to_java.class
+    assert_equal __(Java::JavaLang::Double), 9.32.to_java.class
+    assert_equal __(Java::JavaLang::Boolean), false.to_java.class
+  end
+
+  def test_some_ruby_objects_can_NOT_be_coerced_to_java
+    [[], {}, Object.new].each do |ruby_object|
+      assert_raise(___(NoMethodError)) do
+        ruby_object.to_java_class
+      end
+    end
+  end
+
+  def test_java_collections_are_enumerable
+    java_array = java.util.ArrayList.new
+    java_array << "one" << "two" << "three"
+    assert_equal __(["ONE", "TWO", "THREE"]), java_array.map { |item| item.upcase }
+  end
+
+  # ------------------------------------------------------------------
+
+  # Open the Java ArrayList class and add a new method.
+  class Java::JavaUtil::ArrayList
+    def multiply_all
+      result = 1
+      each do |item|
+        result *= item
+      end
+      result
+    end
+  end
+
+  def test_java_class_are_open_from_ruby
+    java_array = java.util.ArrayList.new
+    java_array.add_all([1,2,3,4,5])
+
+    assert_equal __(120), java_array.multiply_all
+  end
+
+end

src/about_message_passing.rb

@@ -11,19 +11,19 @@ class AboutMessagePassing < EdgeCase::Koan
   def test_methods_can_be_called_directly
     mc = MessageCatcher.new
 
-    assert mc.caught?
+    assert mc.caught?           # __
   end
 
   def test_methods_can_be_invoked_by_sending_the_message
     mc = MessageCatcher.new
 
-    assert mc.send(:caught?)
+    assert mc.send(:caught?)    # __
   end
 
   def test_methods_can_be_invoked_more_dynamically
     mc = MessageCatcher.new
 
-    assert mc.send("caught?")
+    assert mc.send("caught?")   # __
     assert mc.send("caught" + __("?") )    # What do you need to add to the first string?
     assert mc.send("CAUGHT?".____(:downcase) )      # What would you need to do to the string?
   end
@@ -74,7 +74,7 @@ class AboutMessagePassing < EdgeCase::Koan
     exception = assert_raise(___(NoMethodError)) do
       typical.foobar
     end
-    assert_match(/foobar/, exception.message)
+    assert_match(/foobar/, exception.message) # __
   end
 
   def test_calling_method_missing_causes_the_no_method_error
@@ -83,7 +83,7 @@ class AboutMessagePassing < EdgeCase::Koan
     exception = assert_raise(___(NoMethodError)) do
       typical.method_missing(:foobar)
     end
-    assert_match(/foobar/, exception.message)
+    assert_match(/foobar/, exception.message) # __
 
     # THINK ABOUT IT:
     #
@@ -122,7 +122,7 @@ class AboutMessagePassing < EdgeCase::Koan
   def test_catching_messages_makes_respond_to_lie
     catcher = AllMessageCatcher.new
 
-    assert_nothing_raised(NoMethodError) do
+    assert_nothing_raised(NoMethodError) do # __
       catcher.any_method
     end
     assert_equal __(false), catcher.respond_to?(:any_method)

src/about_methods.rb

@@ -19,10 +19,10 @@ class AboutMethods < EdgeCase::Koan
   # considered to be syntactically invalid).
   def test_sometimes_missing_parentheses_are_ambiguous
     #--
-    eval "assert_equal 5, my_global_method(2, 3)" # REMOVE CHECK
+    eval "assert_equal 5, my_global_method(2, 3)" # REMOVE CHECK # __
     if false
       #++
-    eval "assert_equal 5, my_global_method 2, 3" # ENABLE CHECK
+    eval "assert_equal 5, my_global_method 2, 3" # ENABLE CHECK # __
       #--
     end
     #++
@@ -43,12 +43,15 @@ class AboutMethods < EdgeCase::Koan
     exception = assert_raise(___(ArgumentError)) do
       my_global_method
     end
-    assert_match(/#{__("wrong (number|#) of arguments")}/, exception.message)
+    #--
+    pattern = "wrong (number|#) of arguments"
+    #++
+    assert_match(/#{__(pattern)}/, exception.message)
 
     exception = assert_raise(___(ArgumentError)) do
       my_global_method(1,2,3)
     end
-    assert_match(/#{__("wrong (number|#) of arguments")}/, exception.message)
+    assert_match(/#{__(pattern)}/, exception.message)
   end
 
   # ------------------------------------------------------------------

src/about_modules.rb

@@ -44,7 +44,7 @@ class AboutModules < EdgeCase::Koan
 
   def test_module_methods_are_also_availble_in_the_object
     fido = Dog.new
-    assert_nothing_raised(Exception) do
+    assert_nothing_raised(Exception) do # __
       fido.set_name("Rover")
     end
   end

src/about_objects.rb

@@ -0,0 +1,56 @@
+require File.expand_path(File.dirname(__FILE__) + '/edgecase')
+
+class AboutObjects < EdgeCase::Koan
+  def test_everything_is_an_object
+    assert_equal __(true), 1.is_a?(Object)
+    assert_equal __(true), 1.5.is_a?(Object)
+    assert_equal __(true), "string".is_a?(Object)
+    assert_equal __(true), nil.is_a?(Object)
+    assert_equal __(true), Object.is_a?(Object)
+  end
+
+  def test_objects_can_be_converted_to_strings
+    assert_equal __("123"), 123.to_s
+    assert_equal __(""), nil.to_s
+  end
+
+  def test_objects_can_be_inspected
+    assert_equal __("123"), 123.inspect
+    assert_equal __("nil"), nil.inspect
+  end
+
+  def test_every_object_has_an_id
+    obj = Object.new
+    assert_equal __(Fixnum), obj.object_id.class
+  end
+
+  def test_every_object_has_different_id
+    obj = Object.new
+    another_obj = Object.new
+    assert_equal __(true), obj.object_id != another_obj.object_id
+  end
+
+  def test_some_system_objects_always_have_the_same_id
+    assert_equal __(0), false.object_id
+    assert_equal __(2), true.object_id
+    assert_equal __(4), nil.object_id
+  end
+
+  def test_small_integers_have_fixed_ids
+    assert_equal __(1), 0.object_id
+    assert_equal __(3), 1.object_id
+    assert_equal __(5), 2.object_id
+    assert_equal __(201), 100.object_id
+
+    # THINK ABOUT IT:
+    # What pattern do the object IDs for small integers follow?
+  end
+
+  def test_clone_creates_a_different_object
+    obj = Object.new
+    copy = obj.clone
+
+    assert_equal __(true), obj           != copy
+    assert_equal __(true), obj.object_id != copy.object_id
+  end
+end

src/about_regular_expressions.rb

@@ -3,11 +3,11 @@ require File.expand_path(File.dirname(__FILE__) + '/edgecase')
 
 class AboutRegularExpressions < EdgeCase::Koan
   def test_a_pattern_is_a_regular_expression
-    assert_equal Regexp, /pattern/.class
+    assert_equal __(Regexp), /pattern/.class
   end
 
   def test_a_regexp_can_search_a_string_for_matching_content
-    assert_equal "match", "some matching content"[/match/]
+    assert_equal __("match"), "some matching content"[/match/]
   end
 
   def test_a_failed_match_returns_nil

src/about_scope.rb

@@ -29,8 +29,8 @@ class AboutScope < EdgeCase::Koan
     assert_equal __(:jims_dog), fido.identify
     assert_equal __(:joes_dog), rover.identify
 
-    assert_not_equal fido.class, rover.class
-    assert_not_equal Jims::Dog, Joes::Dog
+    assert_equal __(true), fido.class != rover.class
+    assert_equal __(true), Jims::Dog != Joes::Dog
   end
 
   # ------------------------------------------------------------------

src/about_strings.rb

@@ -182,4 +182,12 @@ EOS
     words = ["Now", "is", "the", "time"]
     assert_equal __("Now is the time"), words.join(" ")
   end
+
+  def test_strings_are_not_unique_objects
+    a = "a string"
+    b = "a string"
+
+    assert_equal __(true), a           == b
+    assert_equal __(false), a.object_id == b.object_id
+  end
 end

src/about_symbols.rb

@@ -19,8 +19,8 @@ class AboutSymbols < EdgeCase::Koan
     symbol1 = :a_symbol
     symbol2 = :a_symbol
 
-    assert symbol1.equal?(__(symbol2))
-    assert_equal __(symbol1.object_id), symbol2.object_id
+    assert_equal __(true), symbol1           == symbol2
+    assert_equal __(true), symbol1.object_id == symbol2.object_id
   end
 
   def test_method_names_become_symbols

src/edgecase.rb

@@ -3,6 +3,10 @@
 
 require 'test/unit/assertions'
 
+# --------------------------------------------------------------------
+# Support code for the Ruby Koans.
+# --------------------------------------------------------------------
+
 class FillMeInError < StandardError
 end
 
@@ -16,6 +20,8 @@ def in_ruby_version(*versions)
   yield if versions.any? { |v| ruby_version?(v) }
 end
 
+# Standard, generic replacement value.
+# If value19 is given, it is used inplace of value for Ruby 1.9.
 def __(value="FILL ME IN", value19=:mu)
   if RUBY_VERSION < "1.9"
     value
@@ -24,6 +30,7 @@ def __(value="FILL ME IN", value19=:mu)
   end
 end
 
+# Numeric replacement value.
 def _n_(value=999999, value19=:mu)
   if RUBY_VERSION < "1.9"
     value
@@ -32,10 +39,12 @@ def _n_(value=999999, value19=:mu)
   end
 end
 
+# Error object replacement value.
 def ___(value=FillMeInError)
   value
 end
 
+# Method name replacement.
 class Object
   def ____(method=nil)
     if method
@@ -48,7 +57,25 @@ class Object
   end
 end
 
+class String
+  def side_padding(width)
+    extra = width - self.size
+    if width < 0
+      self
+    else
+      left_padding = extra / 2
+      right_padding = (extra+1)/2
+      (" " * left_padding) + self + (" " *right_padding)
+    end
+  end
+end
+
 module EdgeCase
+  class << self
+    def simple_output
+      ENV['SIMPLE_KOAN_OUTPUT'] == 'true'
+    end
+  end
 
   module Color
     #shamelessly stolen (and modified) from redgreen
@@ -176,6 +203,21 @@ module EdgeCase
     end
 
     def end_screen
+      if EdgeCase.simple_output
+        boring_end_screen
+      else
+        artistic_end_screen
+      end
+    end
+
+    def boring_end_screen
+      puts "Mountains are again merely mountains"
+    end
+
+    def artistic_end_screen
+      "JRuby 1.9.x Koans"
+      ruby_version = "(in #{'J' if defined?(JRUBY_VERSION)}Ruby #{defined?(JRUBY_VERSION) ? JRUBY_VERSION : RUBY_VERSION})"
+      ruby_version = ruby_version.side_padding(54)
         completed = <<-ENDTEXT
                                   ,,   ,  ,,
                                 :      ::::,    :::,
@@ -192,8 +234,8 @@ module EdgeCase
  ,:::::::::::,                                                    ::::::::::::,
  :::::::::::,                                                     ,::::::::::::
 :::::::::::::                                                     ,::::::::::::
-::::::::::::                       Ruby Koans                      ::::::::::::,
-::::::::::::                                                      ,::::::::::::,
+::::::::::::                      Ruby Koans                       ::::::::::::,
+::::::::::::#{                  ruby_version                     },::::::::::::,
 :::::::::::,                                                      , ::::::::::::
 ,:::::::::::::,                brought to you by                 ,,::::::::::::,
 ::::::::::::::                                                    ,::::::::::::
@@ -260,7 +302,7 @@ ENDTEXT
 
     def find_interesting_lines(backtrace)
       backtrace.reject { |line|
-        line =~ /test\/unit\/|edgecase\.rb/
+        line =~ /test\/unit\/|edgecase\.rb|minitest/
       }
     end
 

src/path_to_enlightenment.rb

@@ -4,6 +4,7 @@ $LOAD_PATH << File.dirname(__FILE__)
 
 require 'about_asserts'
 require 'about_nil'
+require 'about_objects'
 require 'about_arrays'
 require 'about_array_assignment'
 require 'about_hashes'
@@ -30,4 +31,7 @@ require 'about_scope'
 require 'about_class_methods'
 require 'about_message_passing'
 require 'about_proxy_object_project'
+in_ruby_version("jruby") do
+  require 'about_java_interop'
+end
 require 'about_extra_credit'