The document provides an overview of ObjectSpace and minitest features in Ruby including: - ObjectSpace allows querying and iterating over all living objects and provides methods to count object sizes and types. - Minitest is a simplified and streamlined version of Test::Unit with a similar interface to RSpec. It provides assertions like refute instead of assert_not and skips tests. - ObjectSpace and minitest/autorun are useful for testing, debugging, and understanding memory usage and object lifetimes in Ruby.

1. HELLO!!!

2. ZOMG HAPPY
SATURDAY!

3. PEW PEW PEW~!!!

4. Aaron Patterson

5. @tenderlove

6. google 'tenderlove'
Might be NSFW

7. AT&T, AT&T logo and all AT&T related marks are trademarks of AT&T Intellectual Property and/or AT&T affiliated companies.

8. Enterprise
Developer
http://github.com/tenderlove/enterprise

9. ruby core
committer

10. rails core
committer

11. rails
committer

12. My Failures

13. rails core
committer

14. rails
committer

15. Presenting Last

16. I like Ryan Davis

17. My Slides Suck
(Sorry Shane)

18. minitest

19. RFC 2119
common.rspec

20. No Parens on
Method Definitions

21. def foo bar, baz
...
end

22. Ruby + JavaScript

23. Ruby + C

24. My Failures
(as a presenter)

25. Fun

26. Practical

27. I am a nerd

28. I like boring things

29. 2 Presentations

30. Practical

31. Fun!

32. The Fun

33. Your Guide to
Presentation
Popularity!

34. Your Guide to
Presentation
Notoriety!

36. •Provocative Title
• Risqué Photos
•Ruby Code?

37. Provocative Title:

38. Use Ruby 1.9 like an
Engineer

39. Use Ruby 1.9 like a
SEXY Engineer

40. Risqué Photos

41. America's Next Top
Model

42. America's Next Top
Engineer

43. Confident

44. Elegant

45. Sultry

46. Sexy

47. Thoughtful

48. Fierce

49. Playful

50. Powerful

51. Provocative

52. Ruby Code?

53. protected
def method_missing(method, *args, &block)
if Array.method_defined?(method)
to_a.send(method, *args, &block)
elsif @klass.scopes[method]
merge(@klass.send(method, *args, &block))
elsif @klass.respond_to?(method)
scoping { @klass.send(method, *args, &block) }
elsif arel.respond_to?(method)
arel.send(method, *args, &block)
elsif match = DynamicFinderMatch.match(method)
attributes = match.attribute_names
super unless @klass.send(:all_attributes_exists?, attributes)
if match.finder?
find_by_attributes(match, attributes, *args)
elsif match.instantiator?
find_or_instantiator_by_attributes(match, attributes, *args, &block)
end
else
super
end
end
private
def references_eager_loaded_tables?
# always convert table names to downcase as in Oracle quoted table names are in uppercase
joined_tables = (tables_in_string(arel.joins(arel)) + [table.name, table.table_alias]).compact.map{ |t|
t.downcase }.uniq
(tables_in_string(to_sql) - joined_tables).any?
end

54. TL;DR

55. The Practical

56. Hidden Gems of
Ruby 1.9

57. Ruby 1.9 PSA

58. minitest

59. require 'minitest/autorun'
class FooTest < MiniTest::Unit::TestCase
WIN32 = true
def test_foo
assert_equal 'foo', 'foo'
end
def test_refutation
refute_equal 'foo', 'bar'
end
def test_skip
return skip if WIN32
assert_equal 'fun!', 'fun!'
end
end

60. require 'minitest/autorun'

61. Test::Unit::TestCase
=>
MiniTest::Unit::TestCase

62. class FooTest < MiniTest::Unit::TestCase
end

63. assert_not_*
=>
refute_*

64. def test_refutation
refute_equal 'foo', 'bar'
end

65. skip

66. class FooTest < MiniTest::Unit::TestCase
WIN32 = true
def test_skip
skip if WIN32
assert_equal 'fun!', 'fun!'
end
end

67. Loaded suite footest
Started
.S.
Finished in 0.000682 seconds.
1) Skipped:
test_skip(FooTest) [footest.rb:15]:
Skipped, no message given
3 tests, 2 assertions, 0 failures, 0 errors, 1 skips

68. randomization

69. class FailTest < MiniTest::Unit::TestCase
@@foos = %w{ hello }
def test_equality
assert_equal @@foos, %w{ hello }
end
def test_append
@@foos << "world"
assert_equal @@foos, %w{ hello world }
end
end

70. Test run options: --seed 31149
Loaded suite failtest
Started
..
Finished in 0.000604 seconds.
2 tests, 2 assertions, 0 failures, 0 errors, 0 skips
Test run options: --seed 31149

71. Test run options: --seed 29650
Loaded suite failtest
Started
.F
Finished in 0.000637 seconds.
1) Failure:
test_equality(FailTest) [failtest.rb:7]:
Expected ["hello", "world"], not ["hello"].
2 tests, 2 assertions, 1 failures, 0 errors, 0 skips
Test run options: --seed 29650

72. Test run options: --seed 29650
Loaded suite failtest
Started
.F
Finished in 0.000637 seconds.
1) Failure:
test_equality(FailTest) [failtest.rb:7]:
Expected ["hello", "world"], not ["hello"].
2 tests, 2 assertions, 1 failures, 0 errors, 0 skips
Test run options: --seed 29650

73. --seed 29650

74. -v

75. ruby failtest.rb --seed 29650 -v

76. Test run options: --seed 29650 --verbose
Loaded suite failtest
Started
FailTest#test_append: 0.00 s: .
FailTest#test_equality: 0.00 s: F
Finished in 0.000735 seconds.
1) Failure:
test_equality(FailTest) [failtest.rb:7]:
Expected ["hello", "world"], not ["hello"].
2 tests, 2 assertions, 1 failures, 0 errors, 0 skips
Test run options: --seed 29650 --verbose

77. Test run options: --seed 29650 --verbose
Loaded suite failtest
Started
FailTest#test_append: 0.00 s: .
FailTest#test_equality: 0.00 s: F
Finished in 0.000735 seconds.
1) Failure:
test_equality(FailTest) [failtest.rb:7]:
Expected ["hello", "world"], not ["hello"].
2 tests, 2 assertions, 1 failures, 0 errors, 0 skips
Test run options: --seed 29650 --verbose

78. Test Performance

79. class FooTest < MiniTest::Unit::TestCase
def test_foo
assert_equal 'foo', 'foo'
end
def test_refutation
refute_equal 'foo', 'bar'
end
def test_slow
sleep 10
end
end

80. class FooTest < MiniTest::Unit::TestCase
def test_foo
assert_equal 'foo', 'foo'
end
def test_refutation
refute_equal 'foo', 'bar'
end
def test_slow
sleep 10
end
end

81. Test run options: --seed 33095 --verbose
Loaded suite footest
Started
FooTest#test_slow: 10.00 s: .
FooTest#test_refutation: 0.00 s: .
FooTest#test_foo: 0.00 s: .
Finished in 10.001114 seconds.
3 tests, 2 assertions, 0 failures, 0 errors, 0 skips
Test run options: --seed 33095 --verbose

82. Test run options: --seed 33095 --verbose
Loaded suite footest
Started
FooTest#test_slow: 10.00 s: .
FooTest#test_refutation: 0.00 s: .
FooTest#test_foo: 0.00 s: .
Finished in 10.001114 seconds.
3 tests, 2 assertions, 0 failures, 0 errors, 0 skips
Test run options: --seed 33095 --verbose

83. With Rake:

84. rake test TESTSOPTS='-v'

85. rspec

86. describe 'Awesome' do
describe 'Class' do
it 'discovers something AMAZING' do
(10 + 10).must_equal 20
end
it 'matches something AMAZING' do
"vuvuzela".must_match /vuvu/
end
it 'raises something AMAZING' do
lambda { raise }.must_raise(RuntimeError)
end
end
end

87. rspec

88. minitest/spec

89. require 'minitest/spec'
require 'minitest/autorun'

90. require 'minitest/spec'
require 'minitest/autorun'
describe 'Awesome' do
describe 'Class' do
it 'discovers something AMAZING' do
(10 + 10).must_equal 20
end
it 'matches something AMAZING' do
"vuvuzela".must_match /vuvu/
end
it 'must raise something' do
lambda { raise }.must_raise(RuntimeError)
end
end
end

91. ObjectSpace

92. ObjectSpace.each_object do |obj|
p obj
end

93. require 'objspace'
• count_objects_size
• memsize_of
• count_nodes
• count_tdata_objects

94. count_object_size
require 'objspace'
hash = {}
ObjectSpace.count_objects_size(hash)
p hash # =>
{:T_CLASS=>291520, :T_MODULE=>42512,
:T_STRING=>26133, :T_REGEXP=>11501,
:T_ARRAY=>5896, :T_HASH=>1088, :T_FILE=>9056,
:T_DATA=>1144348, :TOTAL=>1532054}

95. count_object_size
require 'objspace'
hash = {}
ObjectSpace.count_objects_size(hash)
p hash # =>
{:T_CLASS=>291520, :T_MODULE=>42512,
:T_STRING=>26133, :T_REGEXP=>11501,
:T_ARRAY=>5896, :T_HASH=>1088, :T_FILE=>9056,
:T_DATA=>1144348, :TOTAL=>1532054}

96. memsize_of
require 'objspace'
require 'fiddle'
cl = Fiddle::Closure.new(0, [1])
p ObjectSpace.memsize_of(cl) # => 232

97. memsize_of
require 'objspace'
require 'fiddle'
cl = Fiddle::Closure.new(0, [1])
p ObjectSpace.memsize_of(cl) # => 232

98. Implementation

99. struct rb_data_type_struct
struct rb_data_type_struct {
const char *wrap_struct_name;
struct {
void (*dmark)(void*);
void (*dfree)(void*);
size_t (*dsize)(const void *);
void *reserved[2]; /* For future extension.
This array *must* be filled with ZERO. */
} function;
const rb_data_type_t *parent;
void *data; /* This area can be used for any purpose
by a programmer who define the type. */
};

100. struct rb_data_type_struct
struct rb_data_type_struct {
const char *wrap_struct_name;
struct {
void (*dmark)(void*);
void (*dfree)(void*);
size_t (*dsize)(const void *);
void *reserved[2]; /* For future extension.
This array *must* be filled with ZERO. */
} function;
const rb_data_type_t *parent;
void *data; /* This area can be used for any purpose
by a programmer who define the type. */
};

101. static size_t my_memsize(const void *p) {
return 10;
}
const rb_data_type_t my_data_type = {
"my_extension",
{NULL, NULL, my_memsize,},
};
static VALUE allocate(VALUE klass) {
struct something * cif;
return TypedData_Make_Struct(
klass, something, &my_data_type, cif);
}

102. count_nodes
require 'objspace'
p ObjectSpace.count_nodes #=>
{:NODE_SCOPE=>50, :NODE_BLOCK=>168,
:NODE_IF=>27, :NODE_ITER=>7, ... }

103. count_nodes
require 'objspace'
p ObjectSpace.count_nodes #=>
{:NODE_SCOPE=>50, :NODE_BLOCK=>168,
:NODE_IF=>27, :NODE_ITER=>7, ... }

104. count_nodes
require 'objspace'
10.times do
p ObjectSpace.count_nodes[:NODE_IF]
eval 'if true; end'
end

105. $ ruby objectspace.rb
27
28
29
30
31
32
33
34
35
36
$

106. count_tdata_objects
require 'objspace'
p ObjectSpace.count_tdata_objects # =>
{RubyVM::InstructionSequence=>64,
false=>13, ... }

107. count_tdata_objects
require 'objspace'
p ObjectSpace.count_tdata_objects # =>
{RubyVM::InstructionSequence=>64,
false=>13, ... }

108. count_tdata_objects
require 'objspace'
require 'fiddle'
10.times do
Fiddle::Closure.new(0, [1])
p ObjectSpace.count_tdata_objects[Fiddle::Closure]
end

109. $ ruby objectspace.rb
1
2
3
4
5
6
7
8
9
10
$

110. Fiddle

111. libffi wrapper

112. fiddle + dl

113. Fiddle
• Function calls
• Closure allocation

114. DL
• dlopen() wrapper
• memory management

115. Calling Functions

116. • Open dynamic library
• Locate function pointer
• Wrap function pointer
• Call function

117. Wrapping "sin"
require 'fiddle'
libm = DL.dlopen('libm.dylib')
function = Fiddle::Function.new(
libm['sin'],
[Fiddle::TYPE_DOUBLE],
Fiddle::TYPE_DOUBLE
)
puts function.call(90 * Math::PI / 180)

118. Wrapping "sin"
require 'fiddle'
libm = DL.dlopen('libm.dylib')
function = Fiddle::Function.new(
libm['sin'],
[Fiddle::TYPE_DOUBLE],
Fiddle::TYPE_DOUBLE
)
puts function.call(90 * Math::PI / 180)

119. Wrapping "sin"
require 'fiddle'
libm = DL.dlopen('libm.dylib')
function = Fiddle::Function.new(
libm['sin'],
[Fiddle::TYPE_DOUBLE],
Fiddle::TYPE_DOUBLE
)
puts function.call(90 * Math::PI / 180)

120. Wrapping "sin"
require 'fiddle'
libm = DL.dlopen('libm.dylib')
function = Fiddle::Function.new(
libm['sin'],
[Fiddle::TYPE_DOUBLE],
Fiddle::TYPE_DOUBLE
)
puts function.call(90 * Math::PI / 180)

121. Wrapping "sin"
require 'fiddle'
libm = DL.dlopen('libm.dylib')
function = Fiddle::Function.new(
libm['sin'],
[Fiddle::TYPE_DOUBLE],
Fiddle::TYPE_DOUBLE
)
puts function.call(90 * Math::PI / 180)

122. Creating Closures

123. double (func *)(double)

124. require 'fiddle'
class MySin < Fiddle::Closure
def call number
Math.sin(number)
end
end
function = MySin.new(
Fiddle::TYPE_DOUBLE,
[Fiddle::TYPE_DOUBLE]
)
puts function.call(90 * Math::PI / 180)

125. require 'fiddle'
class MySin < Fiddle::Closure
def call(number)
Math.sin(number)
end
end
function = MySin.new(
Fiddle::TYPE_DOUBLE,
[Fiddle::TYPE_DOUBLE]
)
puts function.call(90 * Math::PI / 180)

126. require 'fiddle'
class MySin < Fiddle::Closure
def call(number)
Math.sin(number)
end
end
function = MySin.new(
Fiddle::TYPE_DOUBLE,
[Fiddle::TYPE_DOUBLE]
)
puts function.call(90 * Math::PI / 180)

127. require 'fiddle'
class MySin < Fiddle::Closure
def call(number)
Math.sin(number)
end
end
function = MySin.new(
Fiddle::TYPE_DOUBLE,
[Fiddle::TYPE_DOUBLE]
)
puts function.call(90 * Math::PI / 180)

128. Using our Closure

129. class MySin < Fiddle::Closure
def call number
Math.sin(number)
end
end
function = MySin.new(
Fiddle::TYPE_DOUBLE,
[Fiddle::TYPE_DOUBLE]
)
cfunc = Fiddle::Function.new(
function,
[Fiddle::TYPE_DOUBLE],
Fiddle::TYPE_DOUBLE
)
puts cfunc.call(90 * Math::PI / 180)

130. class MySin < Fiddle::Closure
def call number
Math.sin(number)
end
end
function = MySin.new(
Fiddle::TYPE_DOUBLE,
[Fiddle::TYPE_DOUBLE]
)
cfunc = Fiddle::Function.new(
function,
[Fiddle::TYPE_DOUBLE],
Fiddle::TYPE_DOUBLE
)
puts cfunc.call(90 * Math::PI / 180)

131. Fiddle Masquerade

132. ruby-ffi code
module Tidy
extend FFI::Library
ffi_lib "libtidy.dylib"
attach_function :tidyFileExists, [:string], :int
attach_function :tidyCreate, [], :pointer
attach_function :tidyParseString, [:pointer, :string], :int
attach_function :tidySaveStdout, [:pointer], :int
end
tdoc = Tidy.tidyCreate
Tidy.tidyParseString tdoc, "<title>Foo</title"
Tidy.tidySaveStdout tdoc

133. In terms of Fiddle

134. module FFI
module Library
TYPE_MAP = {
:string => DL::TYPE_VOIDP,
:pointer => DL::TYPE_VOIDP,
}
DL.constants.each do |const|
next unless const.to_s =~ /^TYPE_/
name = const.to_s.split('_', 2).last.downcase.to_sym
TYPE_MAP[name] = DL.const_get(const)
end
def ffi_lib(lib)
@lib = DL::Handle.new lib
end
def attach_function(name, args, ret)
func = Fiddle::Function.new(
@lib[name.to_s], args.map { |x| TYPE_MAP[x] }, TYPE_MAP[ret]
)
define_singleton_method(name) { |*args| func.call(*args) }
end
end
end

135. ruby-ffi code
module Tidy
extend FFI::Library
ffi_lib "libtidy.dylib"
attach_function :tidyFileExists, [:string], :int
attach_function :tidyCreate, [], :pointer
attach_function :tidyParseString, [:pointer, :string], :int
attach_function :tidySaveStdout, [:pointer], :int
end
tdoc = Tidy.tidyCreate
Tidy.tidyParseString tdoc, "<title>Foo</title"
Tidy.tidySaveStdout tdoc

136. Fiddle code
module Tidy
extend FFI::Library
ffi_lib "libtidy.dylib"
attach_function :tidyFileExists, [:string], :int
attach_function :tidyCreate, [], :pointer
attach_function :tidyParseString, [:pointer, :string], :int
attach_function :tidySaveStdout, [:pointer], :int
end
tdoc = Tidy.tidyCreate
Tidy.tidyParseString tdoc, "<title>Foo</title"
Tidy.tidySaveStdout tdoc

137. Psych

138. YAML Parser
• 1.9.2 and up
• Wraps libyaml
• Replaces Syck
• Opt-in

139. Opt-in Process
$ irb
irb(main):001:0> require 'yaml'
=> true
irb(main):002:0> YAML::ENGINE.syck?
=> true
irb(main):003:0> YAML::ENGINE.yamler = 'psych'
=> "psych"
irb(main):004:0> YAML::ENGINE.syck?
=> false
irb(main):005:0>

140. require 'psych'

141. Parsing & Dumping
require 'psych'
Psych.load('--- hello world!') # => 'hello world!'
Psych.dump('hello world!') # => '--- hello world!'
'hello world!'.to_yaml # => '--- hello world!'

142. JSON
Psych.load("['hello', 'world!']n")
# => ["hello", "world!"]
Psych.to_json(%w{ hello world! })
# => "['hello', 'world!']n"

143. JSON Disclaimer

144. Evented Parsing

145. Evented Parsing
class MyHandler < Psych::Handler
def start_sequence(*args)
puts "open ["
end
def end_sequence(*args)
puts "close ]"
end
def scalar(value, anchor, tag, plain, quoted, style)
puts value
end
end

146. Evented Parsing
parser = Psych::Parser.new(MyHandler.new)
parser.parse(StringIO.new("['foo', 'bar']"))

147. Evented Parsing
$ ruby yml.rb
open [
foo
bar
close ]
$

148. Psych::Parser#parse(io_or_string)

149. Evented Emitting

150. (the hard way)

151. Psych::Emitter
emitter = Psych::Emitter.new($stdout)
emitter.start_stream(Psych::Parser::UTF8)
emitter.start_document([], [], false)
emitter.start_sequence(nil, nil, false, 1)
10.times {
emitter.scalar('hello world', nil, nil, false, true, 1)
}
emitter.end_sequence
emitter.end_document true
emitter.end_stream

152. ---
- 'hello world'
- 'hello world'
- 'hello world'
- 'hello world'
- 'hello world'
- 'hello world'
- 'hello world'
- 'hello world'
- 'hello world'
- 'hello world'

153. Read
Psych::Handler

154. Streamed Emitting

155. (the easy way)

156. Psych::Stream
emitter = Psych::Stream.new($stdout)
emitter.start
emitter.push %w{ one two }
emitter.push %w{ three four }
emitter.finish

157. Psych::Stream
emitter = Psych::Stream.new($stdout)
emitter.start
emitter.push %w{ one two }
emitter.push %w{ three four }
emitter.finish

158. Psych::Stream
$ ruby yml.rb
---
- one
- two
...
---
- three
- four
...

159. Problem?

160. Streaming JSON

161. Psych::Stream
emitter = Psych::Stream.new($stdout)
emitter.start
emitter.push %w{ one two }
emitter.push %w{ three four }
emitter.finish

162. Psych::JSON::Stream
emitter = Psych::JSON::Stream.new($stdout)
emitter.start
emitter.push %w{ one two }
emitter.push %w{ three four }
emitter.finish

163. Psych::JSON::Stream
emitter = Psych::JSON::Stream.new($stdout)
emitter.start
emitter.push %w{ one two }
emitter.push %w{ three four }
emitter.finish

164. Psych::JSON::Stream
--- ['one', 'two']
...
--- ['three', 'four']
...

165. Uses?

166. More Info

167. THE END

169. Questions?

170. Coverage

171. Methods
• Coverage.start
• Coverage.result

172. a.rb
###
# It's my class!
class Foo
def initialize
@thought = 0
10.times {
@thought += 1 # thinking
}
end
def rested?
if @thought > 8
false
else
true
end
end
end
Foo.new.rested?

173. a.rb
###
# It's my class!
class Foo
def initialize
@thought = 0
10.times {
@thought += 1 # thinking
}
end
def rested?
if @thought > 8
false
else
true
end
end
end
Foo.new.rested?

174. a.rb
###
# It's my class!
class Foo
def initialize
@thought = 0
10.times {
@thought += 1 # thinking
}
end
def rested?
if @thought > 8
false
else
true
end
end
end
Foo.new.rested?

175. a.rb
###
# It's my class!
class Foo
def initialize
@thought = 0
10.times {
@thought += 1 # thinking
}
end
def rested?
if @thought > 8
false
else
true
end
end
end
Foo.new.rested?

176. require 'coverage'
Coverage.start
require 'a'
p Coverage.result

177. require 'coverage'
Coverage.start
require 'a'
p Coverage.result

178. Coverage.result
{"/Users/apatterson/git/code/a.rb"=>[nil,
nil, 1, 1, 1, 1, 10, nil, nil, nil, 1, 1, 1,
nil, 0, nil, nil, nil, nil, 1]}

179. We've Learned

180. We've Learned
• Lines executed

181. We've Learned
• Lines executed
• # times a line was executed

182. We've Learned
• Lines executed
• # times a line was executed
• Lines that can't be executed

183. We can deduce

184. We can deduce
• Coverage

185. We can deduce
• Coverage
• Hotspots (code heatmap)

186. SimpleCov
http://github.com/colszowka/simplecov

187. Read More Here!
http://bit.ly/19coverage