Add the CoffeeScript compiler and clean up some specs

lib/rake-pipeline-web-filters.rb

@@ -17,5 +17,6 @@ module Filters
 require "rake-pipeline-web-filters/ordering_concat_filter"
 require "rake-pipeline-web-filters/sass_compiler"
 require "rake-pipeline-web-filters/tilt_filter"
+require "rake-pipeline-web-filters/coffee_script_compiler"
 require "rake-pipeline-web-filters/helpers"
 

lib/rake-pipeline-web-filters/coffee_script_compiler.rb

@@ -0,0 +1,26 @@
+module Rake::Pipeline::Web::Filters
+  # A filter that compiles CoffeeScript to JavaScript.
+  class CoffeeScriptCompiler < Rake::Pipeline::Filter
+    # By default, the CoffeeScriptCompiler converts inputs
+    # with the extension +.coffee+ to +.js+.
+    #
+    # @param [Proc] block the output name generator block
+    def initialize(&block)
+      block ||= proc { |input| input.sub(/\.coffee$/, '.js') }
+      super(&block)
+    end
+
+    # The body of the filter. Compile each input file into
+    # a CoffeeScript compiled output file.
+    #
+    # @param [Array] inputs an Array of FileWrapper objects.
+    # @param [FileWrapper] output a FileWrapper object
+    def generate_output(inputs, output)
+      require "coffee-script"
+
+      inputs.each do |input|
+        output.write CoffeeScript.compile(input)
+      end
+    end
+  end
+end

rake-pipeline-web-filters.gemspec

@@ -21,5 +21,6 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency "tilt"
   gem.add_development_dependency "sass"
   gem.add_development_dependency "compass"
+  gem.add_development_dependency "coffee-script"
   gem.add_development_dependency "redcarpet", '~> 2.0'
 end

spec/coffee_filter_spec.rb

@@ -0,0 +1,62 @@
+describe "CoffeeScriptCompiler" do
+  CoffeeScriptCompiler = Rake::Pipeline::Web::Filters::CoffeeScriptCompiler
+
+  COFFEE_INPUT = <<-COFFEE
+x = 1;
+
+y = ->
+  x += 1
+  COFFEE
+
+  EXPECTED_COFFEE_OUTPUT = <<-HTML
+(function() {
+  var x, y;
+  x = 1;
+  y = function() {
+    return x += 1;
+  };
+}).call(this);
+  HTML
+
+  def input_file(name, content)
+    MemoryFileWrapper.new("/path/to/input", name, "UTF-8", content)
+  end
+
+  def output_file(name)
+    MemoryFileWrapper.new("/path/to/output", name, "UTF-8")
+  end
+
+  def setup_filter(filter)
+    filter.file_wrapper_class = MemoryFileWrapper
+    filter.input_files = [input_file("input.coffee", COFFEE_INPUT)]
+    filter.output_root = "/path/to/output"
+    filter.rake_application = Rake::Application.new
+    filter
+  end
+
+  it "generates output" do
+    filter = setup_filter CoffeeScriptCompiler.new
+
+    filter.output_files.should == [output_file("input.js")]
+
+    tasks = filter.generate_rake_tasks
+    tasks.each(&:invoke)
+
+    file = MemoryFileWrapper.files["/path/to/output/input.js"]
+    file.body.should == EXPECTED_COFFEE_OUTPUT
+    file.encoding.should == "UTF-8"
+  end
+
+  describe "naming output files" do
+    it "translates .coffee extensions to .js by default" do
+      filter = setup_filter CoffeeScriptCompiler.new
+      filter.output_files.first.path.should == "input.js"
+    end
+
+    it "accepts a block to customize output file names" do
+      filter = setup_filter(CoffeeScriptCompiler.new { |input| "octopus" })
+      filter.output_files.first.path.should == "octopus"
+    end
+  end
+end
+

spec/markdown_compiler_spec.rb

@@ -1,5 +1,4 @@
 describe "MarkdownCompiler" do
-  MemoryFileWrapper = Rake::Pipeline::SpecHelpers::MemoryFileWrapper
   MarkdownCompiler = Rake::Pipeline::Web::Filters::MarkdownCompiler
 
   MARKDOWN_INPUT = <<-MARKDOWN

spec/minispade_filter_spec.rb

@@ -1,6 +1,4 @@
 describe "MinispadeFilter" do
-  MemoryFileWrapper = Rake::Pipeline::SpecHelpers::MemoryFileWrapper
-
   let(:input_files) {
     [
       MemoryFileWrapper.new("/path/to/input", "foo.js", "UTF-8", "var foo = 'bar';")

spec/ordering_concat_filter_spec.rb

@@ -1,6 +1,4 @@
 describe "OrderingConcatFilter" do
-  MemoryFileWrapper = Rake::Pipeline::SpecHelpers::MemoryFileWrapper
-
   let(:input_files) {
     [
       MemoryFileWrapper.new("/path/to/input", "first.txt", "UTF-8", "FIRST"),

spec/sass_compiler_spec.rb

@@ -1,5 +1,4 @@
 describe "SassCompiler" do
-  MemoryFileWrapper = Rake::Pipeline::SpecHelpers::MemoryFileWrapper
   SassCompiler = Rake::Pipeline::Web::Filters::SassCompiler
 
   SCSS_INPUT = <<-SCSS

spec/spec_helper.rb

@@ -62,6 +62,7 @@ def age_existing_files
 
     module Filters
       ConcatFilter = Rake::Pipeline::ConcatFilter
+      MemoryFileWrapper = Rake::Pipeline::SpecHelpers::MemoryFileWrapper
 
       class StripAssertsFilter < Rake::Pipeline::Filter
         def generate_output(inputs, output)

spec/tilt_filter_spec.rb

@@ -1,6 +1,4 @@
 describe "TiltFilter" do
-  MemoryFileWrapper = Rake::Pipeline::SpecHelpers::MemoryFileWrapper
-
   let(:input_files) {
     [
       MemoryFileWrapper.new("/path/to/input", "foo.erb", "UTF-8", "<%= 'foo' %>\n"),