Rakefile

require 'rake/packagetask'

MECHANIC_VERSION  = "0.1.0"

MECHANIC_ROOT     = File.expand_path(File.dirname(__FILE__))
MECHANIC_SRC_DIR  = File.join(MECHANIC_ROOT, 'src')
MECHANIC_DIST_DIR = File.join(MECHANIC_ROOT, 'dist')
MECHANIC_PKG_DIR  = File.join(MECHANIC_ROOT, 'pkg')

MECHANIC_COMPONENTS = [
  'mechanic-core',
  'logging',
  'data',
  'events'
]

task :default => [:clean, :concat, :dist]

# MECHANIC_TESTS = %w[
#   test/mechanic.html
#   test/ajax.html
#   test/data.html
#   test/detect.html
#   test/form.html
#   test/fx.html
#   test/polyfill.html
# ]

desc "Clean the distribution directory."
task :clean do
  rm_rf MECHANIC_DIST_DIR
  mkdir MECHANIC_DIST_DIR
end

def normalize_whitespace(filename)
  contents = File.readlines(filename)
  contents.each { |line| line.sub!(/\s+$/, "") }
  File.open(filename, "w") do |file|
    file.write contents.join("\n").sub(/(\n+)?\Z/m, "\n")
  end
end

desc "Strip trailing whitespace and ensure each file ends with a newline"
task :whitespace do
  Dir["*", "src/**/*", "test/**/*", "examples/**/*"].each do |filename|
    normalize_whitespace(filename) if File.file?(filename)
  end
end

desc "Concatenate source files to build for release"
task :concat, [:addons] => :whitespace do |task, args|
  # colon-separated arguments such as `concat[foo:bar:-baz]` specify
  # which components to add or exclude, depending on if it starts with "-"
  add, exclude = args[:addons].to_s.split(':').partition {|c| c !~ /^-/ }
  exclude.each {|c| c.sub!('-', '') }
  components = (MECHANIC_COMPONENTS | add) - exclude

  unless components == MECHANIC_COMPONENTS
    puts "Building release by including: #{components.join(', ')}"
  end

  File.open(File.join(MECHANIC_DIST_DIR, 'mechanic.js'), 'w') do |f|
    f.puts components.map { |component|
      File.read File.join(MECHANIC_SRC_DIR, "#{component}.js")
    }
  end
end

def google_compiler(src, target)
  puts "Minifying #{src} with Google Closure Compiler..."
  `java -jar vendor/google-compiler/compiler.jar --js #{src} --summary_detail_level 3 --js_output_file #{target}`
end

def process_minified(src, target)
  cp target, File.join(MECHANIC_DIST_DIR,'temp.js')
  msize = File.size(File.join(MECHANIC_DIST_DIR,'temp.js'))
  `gzip -9 #{File.join(MECHANIC_DIST_DIR,'temp.js')}`

  osize = File.size(src)
  dsize = File.size(File.join(MECHANIC_DIST_DIR,'temp.js.gz'))
  rm_rf File.join(MECHANIC_DIST_DIR,'temp.js.gz')

  puts "Original version: %.3fk" % (osize/1024.0)
  puts "Minified: %.3fk" % (msize/1024.0)
  puts "Minified and gzipped: %.3fk, compression factor %.3f" % [dsize/1024.0, osize/dsize.to_f]
end

desc "Generates a minified version for distribution using the Google Closure compiler."
task :dist do
  src, target = File.join(MECHANIC_DIST_DIR,'mechanic.js'), File.join(MECHANIC_DIST_DIR,'mechanic.min.js')
  google_compiler src, target
  process_minified src, target
end

Rake::PackageTask.new('mechanic', MECHANIC_VERSION) do |package|
  package.need_tar_gz = true
  package.need_zip = true
  package.package_dir = MECHANIC_PKG_DIR
  package.package_files.include(
    'README.md',
    'LICENSE',
    'dist/**/*',
    'src/**/*',
    'test/**/*',
    'vendor/evidence.js',
    'examples/**/*'
  ).exclude(*`git ls-files -o test src examples -z`.split("\0"))
end

def silence_warnings
  require 'stringio'
  begin
    old_stderr = $stderr
    $stderr = StringIO.new
    yield
  ensure
    $stderr = old_stderr
  end
end