on haml 2.0.9

require 'haml/engine'

template_broken = '
:javascript
  - [1, 2, 3, 4].each do |item|
    = "Hey #{item}"
'

puts Haml::Engine.new(template_broken).to_html

causes

(haml):3:in `to_html': undefined local variable or method `item' for #<Object:0x2bedf64> (NameError)
        from c:/ruby/lib/ruby/gems/1.8/gems/haml-2.0.9/lib/haml/engine.rb:149:in `to_html'
        from c:/ruby/lib/ruby/gems/1.8/gems/haml-2.0.9/lib/haml/engine.rb:149:in `instance_eval'
        from c:/ruby/lib/ruby/gems/1.8/gems/haml-2.0.9/lib/haml/engine.rb:149:in `to_html'
        from haml.rb:9

Replacing :javascript filter with regular %script tag fixed the issue. It’s a workaround.

require 'haml/engine'

template_broken = '
%script
  - [1, 2, 3, 4].each do |item|
    = "Hey #{item}"
'

puts Haml::Engine.new(template_broken).to_html

I noticed that depending on the syntax used, rcov (0.8.1.2.0 win32) can give false positives. For example, when putting blocks on the same line as methods that execute them, if the method was called and block wasn’t, the line would still be colored as “covered”.

In the image above you can see that line #23 isn’t covered, where as #28 is. Problem is, I don’t have any tests yet hitting XML portion.

What’s even more interesting is that using { } syntax on multiple lines gives false positives just the same – you have to use do/end syntax specifically. Only, and only then rcov will process the block correctly.

Something to keep in mind.

Update: I have tested this on OSX and the issue is exactly the same.

Trying to get a windows rails environment going this morning I stumbled upon something interesting – all ‘a’ characters were missing from cucumber and rspec output.

This has something to do with UTF-8 encoding and there’s a ticket and wiki post on cucumber about it, but no solution that I found acceptable.

Everything comes down to having change encoding in the current cmd window. This is achieved via a simple call to chcp 1252, but nobody want’s to do this every time, right?

To get this executed automaticaly and without resorting to serious registry editing, simply add this line to your cucmber.bat and any other batch files that are exhibiting this problem. You can find cucumber.bat in your /ruby/bin folder.

Here’s what it looks like:

chcp 1252
@ECHO OFF
IF NOT "%~f0" == "~f0" GOTO :WinNT
@"ruby.exe" "c:/ruby/bin/cucumber" %1 %2 %3 %4 %5 %6 %7 %8 %9
GOTO :EOF
:WinNT
@"ruby.exe" "%~dpn0" %*

I have run into a weird exception when using my favorite IO gem RIO (btw, Noobkit page got beaten with the ugly stick and parser needs a spanking).

Exception occur when calling rio(...).rmtree or rio(...).mkpath or rio(...).mkdir. It reads as follows: “wrong number of arguments (0 for 1)”. I know for a fact that these methods don’t take any arguments, but just for kicks, passing a single random argument results in an ironic “wrong number of arguments (1 for 0)”.

Basically the problem came down to the fact that RIO doesn’t like Rake. I can live without Rake, but not without RIO.

GEMS=( `cat gems.txt` ) # gems.txt has one gem name per line

for gem in "${GEMS[@]}"; do
  found=`gem list $gem | grep -i $gem`
  if [ "$found" != "" ]; then
    parts=( $found )
    echo "Found ${parts[0]} ${parts[1]}"
    continue
  fi

  echo "---------------------------"
  echo "Installing $gem"
  sudo gem install $gem -y
  echo "---------------------------"
done

module Spec
  module DSL
    module BehaviourEval
      module ModuleMethods
        def it(description = :__generate_description, opts = {}, &block)
          return if @it_only_found
          examples << Example.new(description, opts, &block)
        end

        # Same as +it+ only blocks all other examples making this the
        # only example that would run.
        def it_only(description = :__generate_description, opts = {}, &block)
          @it_only_found = true
          @examples = [Example.new(description, opts, &block)]
        end
      end
    end
  end
end

Drop this into your spec_helper.rb and now if you want to focus on a single example, just make it “it_only” instead of “it“.

Here are a few steps that you need to get it to work.

1. Open up Synaptic Package Manager from System > Preferences
2. Search for “ruby1.8-dev”, right click and check “Mark for installation”
3. Search for “build-essential” and mark it for installation as well
4. Click “Apply” in the toolbar

After the update is finished, you should be able to install Gems which require native extensions compilation.

This was the assumption that I approached a simple task with – stripping slashes from beginning and end of a string. Here’s the code:

path = path[1..-1] if path[0, 1] == '/'
path = path[0..-2] if path[-1, 1] == '/'

I would naturally assume that the block above would be faster than path.gsub!(/^\/|\/$/, ''). But just in case, lets benchmark to be sure.

require 'benchmark'

original = '/hello/somewhat/long/path/here/'
max = 1_000_000

puts Benchmark.measure {
  1.upto(max) do
    path = original
    path = path[1..-1] if path[0, 1] == '/'
    path = path[0..-2] if path[-1, 1] == '/'
  end
}

puts Benchmark.measure {
  1.upto(max) do
    path = original
    path.gsub!(/^/|/$/, '')
  end
}

# prints out
  4.212000   0.000000   4.212000 (  4.270000)
  2.418000   0.000000   2.418000 (  2.435000)

I don’t understand why, but gsub is 57% faster. I find it hard to believe that a few extra Ruby statements introduce so much overhead that it becomes slower than entire regular expressions engine. Anyone has any explanation for this?

def hash_history(hash, desired_key, &block)
  return false unless Hash === hash

  hash.each_pair do |key, value|
    if key == desired_key or hash_history(value, desired_key, &block)
      yield(key, value)
      return true
    end
  end

  return false
end

hash = {
  :level_1 => {
    :level_2 => {
      :level_3 => {
        :search => 'test'
      }
    }
  }
}

hash_history(hash, :search) { |key, value| puts key }

# prints out...
# search
# level_3
# level_2
# level_1

Here’s the fix in parser_rb.rb:

...

def parse_attr(context, single, tk, comment)
  args = parse_symbol_arg(1)
  if args.size > 0
    name = args[0]
    rw = "R"
    skip_tkspace(false)
    tk = get_tk
    if tk.kind_of? TkCOMMA
      rw = "RW" if get_bool
    else
      unget_tk tk
    end
    att = Attr.new(get_tkread, name, rw, comment)
    att.top_level = @top_level
    att.visibility = context.visibility  ######### NEW LINE ##########
    read_documentation_modifiers(att, ATTR_MODIFIERS)
    if att.document_self
      context.add_attribute(att)
    end
  else
    warn("'attr' ignored - looks like a variable")
  end
end

...

def parse_attr_accessor(context, single, tk, comment)
  args = parse_symbol_arg
  read = get_tkread
  rw = "?"

  # If nodoc is given, don't document any of them

  tmp = CodeObject.new
  read_documentation_modifiers(tmp, ATTR_MODIFIERS)
  return unless tmp.document_self

  case tk.name
  when "attr_reader"   then rw = "R"
  when "attr_writer"   then rw = "W"
  when "attr_accessor" then rw = "RW"
  else
    rw = @options.extra_accessor_flags[tk.name]
  end

  for name in args
    att = Attr.new(get_tkread, name, rw, comment)
    att.top_level = @top_level
    att.visibility = context.visibility   ######### NEW LINE ##########
    context.add_attribute(att)
  end
end