dbrady · May 26, 2011 06:05 · JEG2 · May 27, 2011 · dbrady · May 27, 2011
diff --git a/csv_tests.rb b/csv_tests.rb
 #!/usr/bin/env ruby

 unless RUBY_VERSION.start_with? "1.9"
  puts "This test file is for Ruby 1.9.x"
  exit -1
 end

 require 'csv'
 require 'test/unit'


 # Hi James!

 # This is written with love and respect. I'm a little cranky with this
 # code at the moment, but I think once you see what I'm seeing you'll
 # probably agree.

 # 0. This is maddening. I just went to pull up the docco that I was
 # working off of today, and I can't find it. I just found THIS page,
 # which DOES have the examples I was hoping to find:
 #
 # http://www.ruby-doc.org/ruby-1.9/index.html
 #
 # Hang on, lemme go crack open the work laptop. Oh, wild. I was
 # working entirely off of the CSV::Table documentation, because that's
 # where Google led me.


 # 1. I didn't get that CSV was a file I/O based metaphor from its
 # documentation at all. That's because it doesn't HAVE much
 # documentation. This thing NEEDS some examples desperately. Stack
 # Overflow has a few examples of people saying "is there a simple
 # example of how to use CSV?" It would be REALLY helpful if those
 # simple examples were in the rdoc.

 # 2. Note that my use case is probably simple and edge-casey. I'm not
 # streaming data. I'm grabbing a CSV file wholesale, reading it in one
 # go, and then pushing it out to an HTML table--that isn't allowed to
 # get friendly with the report's native data format, so NO, it can't
 # just use CSV's iteration helpers. :-)

 # 3. I TOTALLY expected that CSV would uphold the Enumerable contract,
 # because it says "Modules included: Enumerable" right on the tin.

 # dbrady's not so very humble opinion: this cost me an hour of
 # debugging time late in the afternoon of a deploy day. If you don't
 # want to change it because I'm just using it wrong, PLEASE document
 # this. I read your existing documentation in good faith and with a
 # careful eye and was led down the garden path. (See point 0 above,
 # though--I didn't know there was a CSV page apart from CSV::Table. I
 # blame the crappy 4-iframe bullshit indexing of RDoc, that forces me
 # to use Google to search the damn documentation.)

 # Then again, if you're not shocked and appalled by the tests that
 # follow, what I *really* want to know is who are you and what have
 # you done with James Edward Gray II?

 # The tests that follow are in two groups. test_workaround_* tests DO
 # pass, but demonstrate the need to completely reach up CSV's butt and
 # violate its encapsulation rather vigorously. All other tests fail,
 # demonstrating the problem that CSV presents an Enumerable and/or
 # random-access interface that is completely dependent on the StringIO
 # seek position.



 class TestCsvSeekDependencies < Test::Unit::TestCase
  def setup
  @csv = CSV.new(<<PETS, :headers => true)
 "name","type","age"
 Noni,"Border Collie/Golden Retriever Mix",8
 BamBam,Cat,2
 Pebbles,Cat,2
 PETS

  end

  def test_sanity
    assert true, "This really should have been true."
  end

  def test_headers_do_not_depend_on_first_fetch
    assert_equal ["name", "type", "age"], @csv.headers
  end

  def test_workaround_headers_do_not_depend_on_first_fetch
    @csv.count
    assert_equal ["name", "type", "age"], @csv.headers
  end

  def test_headers_does_not_get_erased_by_rewind
    @csv.count
    assert_equal ["name", "type", "age"], @csv.headers
    @csv.rewind
    assert_equal ["name", "type", "age"], @csv.headers
  end

  def test_count_does_not_depend_on_seek_position
    assert_equal 3, @csv.count
    assert_equal 3, @csv.count
  end

  def test_workaround_count_does_not_depend_on_seek_position
    assert_equal 3, @csv.count
    @csv.rewind
    assert_equal 3, @csv.count
    @csv.rewind
    assert_equal 3, @csv.count
  end

  def test_first_does_not_depend_on_seek_position
    assert_equal "Noni", @csv.first["name"]
    assert_equal "Noni", @csv.first["name"]
  end

  def test_workaround_first_does_not_depend_on_seek_position
    assert_equal "Noni", @csv.first["name"]
    @csv.rewind
    assert_equal "Noni", @csv.first["name"]
  end

  def test_first_does_not_depend_on_count_not_having_been_called_previously
    assert_equal "Noni", @csv.first["name"]
    assert_equal 3, @csv.count
  end

  def test_workaround_first_does_not_depend_on_count_not_having_been_called_previously
    assert_equal "Noni", @csv.first["name"]
    @csv.rewind
    assert_equal 3, @csv.count
  end

  def test_each_should_not_depend_on_each_not_having_been_called
    names = []
    @csv.each do |row|
      names << row["name"]
    end
    assert_equal ["Noni", "BamBam", "Pebbles"], names
    names = []
    @csv.each do |row|
      names << row["name"]
    end
    assert_equal ["Noni", "BamBam", "Pebbles"], names
  end

  def test_each_should_not_depend_on_first_not_having_been_called
    names = []
    @csv.first
    @csv.each do |row|
      names << row["name"]
    end
    assert_equal ["Noni", "BamBam", "Pebbles"], names
  end

  def test_map_should_not_depend_on_geez_we_get_it_already
    names = @csv.map {|row| row["name"] }
    assert_equal ["Noni", "BamBam", "Pebbles"], names
    names = @csv.map {|row| row["name"] }
    assert_equal ["Noni", "BamBam", "Pebbles"], names
  end

  def test_anyp_should_not_depend_on_well_you_see_the_problem_now
    assert_equal true, @csv.any? {|row| row["name"] == "BamBam"}
    # next line passes, because seek pos is left at line 2
    assert_equal true, @csv.any? {|row| row["name"] == "Pebbles"}
    # fails because seek pos is now at EOF
    assert_equal true, @csv.any? {|row| row["name"] == "Noni"}
  end

  def test_etc_and_so_forth_for_all_of_enumerable
    @csv.count
    assert_equal [["name", "BamBam"], ["type", "Cat"], ["age", "2"]], @csv.find {|row| row["name"] == "BamBam"}.to_a
    assert_equal 12, @csv.inject(0) {|a,b| a + b["age"].to_i}
    assert_equal [["name", "Pebbles"], ["type", "Cat"], ["age", "2"]], @csv.drop(2)[0].to_a
    # ...etc...
  end


  def test_if_youre_gonna_play_in_texas_you_gotta_have_grep_in_the_band
    # this would ALSO be dependent on seek position if it wasn't broken
    assert_not_equal [], @csv.grep(/BamBam/)
  end
 end

 # So... there you go. I hope you find this useful, and I *REALLY* hope
 # you'll continue to support Enumerable in CSV. By which I mean start
 # supporting. *cough* ;-)

 # It may not be possible to leave the seek position alone while
 # guaranteeing that Enumerable functions like map() and first() work
 # correctly. You may well need to split Enumerable out of CSV
 # altogether. If you do, like I said above, PLEASE provide a way to
 # permit it, even if it means casting the whole file to_a or similar.
 # Cf. ruby's IO#read_lines() method that just gives you back an array.

 # Thanks for all your hard work! I'm grumpy because of time lost and
 # the mega schedule stress it induced. I am NOT grumpy that you
 # created this library and put it out there. Which is why I'm giving
 # you unit tests rather than a complaint form. :-)
	#!/usr/bin/env ruby

	unless RUBY_VERSION.start_with? "1.9"
	puts "This test file is for Ruby 1.9.x"
	exit -1
	end

	require 'csv'
	require 'test/unit'


	# Hi James!

	# This is written with love and respect. I'm a little cranky with this
	# code at the moment, but I think once you see what I'm seeing you'll
	# probably agree.

	# 0. This is maddening. I just went to pull up the docco that I was
	# working off of today, and I can't find it. I just found THIS page,
	# which DOES have the examples I was hoping to find:
	#
	# http://www.ruby-doc.org/ruby-1.9/index.html
	#
	# Hang on, lemme go crack open the work laptop. Oh, wild. I was
	# working entirely off of the CSV::Table documentation, because that's
	# where Google led me.


	# 1. I didn't get that CSV was a file I/O based metaphor from its
	# documentation at all. That's because it doesn't HAVE much
	# documentation. This thing NEEDS some examples desperately. Stack
	# Overflow has a few examples of people saying "is there a simple
	# example of how to use CSV?" It would be REALLY helpful if those
	# simple examples were in the rdoc.

	# 2. Note that my use case is probably simple and edge-casey. I'm not
	# streaming data. I'm grabbing a CSV file wholesale, reading it in one
	# go, and then pushing it out to an HTML table--that isn't allowed to
	# get friendly with the report's native data format, so NO, it can't
	# just use CSV's iteration helpers. :-)

	# 3. I TOTALLY expected that CSV would uphold the Enumerable contract,
	# because it says "Modules included: Enumerable" right on the tin.

	# dbrady's not so very humble opinion: this cost me an hour of
	# debugging time late in the afternoon of a deploy day. If you don't
	# want to change it because I'm just using it wrong, PLEASE document
	# this. I read your existing documentation in good faith and with a
	# careful eye and was led down the garden path. (See point 0 above,
	# though--I didn't know there was a CSV page apart from CSV::Table. I
	# blame the crappy 4-iframe bullshit indexing of RDoc, that forces me
	# to use Google to search the damn documentation.)

	# Then again, if you're not shocked and appalled by the tests that
	# follow, what I really want to know is who are you and what have
	# you done with James Edward Gray II?

	# The tests that follow are in two groups. test_workaround_* tests DO
	# pass, but demonstrate the need to completely reach up CSV's butt and
	# violate its encapsulation rather vigorously. All other tests fail,
	# demonstrating the problem that CSV presents an Enumerable and/or
	# random-access interface that is completely dependent on the StringIO
	# seek position.



	class TestCsvSeekDependencies < Test::Unit::TestCase
	def setup
	@csv = CSV.new(<<PETS, :headers => true)
	"name","type","age"
	Noni,"Border Collie/Golden Retriever Mix",8
	BamBam,Cat,2
	Pebbles,Cat,2
	PETS

	end

	def test_sanity
	assert true, "This really should have been true."
	end

	def test_headers_do_not_depend_on_first_fetch
	assert_equal ["name", "type", "age"], @csv.headers
	end

	def test_workaround_headers_do_not_depend_on_first_fetch
	@csv.count
	assert_equal ["name", "type", "age"], @csv.headers
	end

	def test_headers_does_not_get_erased_by_rewind
	@csv.count
	assert_equal ["name", "type", "age"], @csv.headers
	@csv.rewind
	assert_equal ["name", "type", "age"], @csv.headers
	end

	def test_count_does_not_depend_on_seek_position
	assert_equal 3, @csv.count
	assert_equal 3, @csv.count
	end

	def test_workaround_count_does_not_depend_on_seek_position
	assert_equal 3, @csv.count
	@csv.rewind
	assert_equal 3, @csv.count
	@csv.rewind
	assert_equal 3, @csv.count
	end

	def test_first_does_not_depend_on_seek_position
	assert_equal "Noni", @csv.first["name"]
	assert_equal "Noni", @csv.first["name"]
	end

	def test_workaround_first_does_not_depend_on_seek_position
	assert_equal "Noni", @csv.first["name"]
	@csv.rewind
	assert_equal "Noni", @csv.first["name"]
	end

	def test_first_does_not_depend_on_count_not_having_been_called_previously
	assert_equal "Noni", @csv.first["name"]
	assert_equal 3, @csv.count
	end

	def test_workaround_first_does_not_depend_on_count_not_having_been_called_previously
	assert_equal "Noni", @csv.first["name"]
	@csv.rewind
	assert_equal 3, @csv.count
	end

	def test_each_should_not_depend_on_each_not_having_been_called
	names = []
	@csv.each do \|row\|
	names << row["name"]
	end
	assert_equal ["Noni", "BamBam", "Pebbles"], names
	names = []
	@csv.each do \|row\|
	names << row["name"]
	end
	assert_equal ["Noni", "BamBam", "Pebbles"], names
	end

	def test_each_should_not_depend_on_first_not_having_been_called
	names = []
	@csv.first
	@csv.each do \|row\|
	names << row["name"]
	end
	assert_equal ["Noni", "BamBam", "Pebbles"], names
	end

	def test_map_should_not_depend_on_geez_we_get_it_already
	names = @csv.map {\|row\| row["name"] }
	assert_equal ["Noni", "BamBam", "Pebbles"], names
	names = @csv.map {\|row\| row["name"] }
	assert_equal ["Noni", "BamBam", "Pebbles"], names
	end

	def test_anyp_should_not_depend_on_well_you_see_the_problem_now
	assert_equal true, @csv.any? {\|row\| row["name"] == "BamBam"}
	# next line passes, because seek pos is left at line 2
	assert_equal true, @csv.any? {\|row\| row["name"] == "Pebbles"}
	# fails because seek pos is now at EOF
	assert_equal true, @csv.any? {\|row\| row["name"] == "Noni"}
	end

	def test_etc_and_so_forth_for_all_of_enumerable
	@csv.count
	assert_equal [["name", "BamBam"], ["type", "Cat"], ["age", "2"]], @csv.find {\|row\| row["name"] == "BamBam"}.to_a
	assert_equal 12, @csv.inject(0) {\|a,b\| a + b["age"].to_i}
	assert_equal [["name", "Pebbles"], ["type", "Cat"], ["age", "2"]], @csv.drop(2)[0].to_a
	# ...etc...
	end


	def test_if_youre_gonna_play_in_texas_you_gotta_have_grep_in_the_band
	# this would ALSO be dependent on seek position if it wasn't broken
	assert_not_equal [], @csv.grep(/BamBam/)
	end
	end

	# So... there you go. I hope you find this useful, and I REALLY hope
	# you'll continue to support Enumerable in CSV. By which I mean start
	# supporting. cough ;-)

	# It may not be possible to leave the seek position alone while
	# guaranteeing that Enumerable functions like map() and first() work
	# correctly. You may well need to split Enumerable out of CSV
	# altogether. If you do, like I said above, PLEASE provide a way to
	# permit it, even if it means casting the whole file to_a or similar.
	# Cf. ruby's IO#read_lines() method that just gives you back an array.

	# Thanks for all your hard work! I'm grumpy because of time lost and
	# the mega schedule stress it induced. I am NOT grumpy that you
	# created this library and put it out there. Which is why I'm giving
	# you unit tests rather than a complaint form. :-)