add cookie support to response

This commit adds support for response cookies. Response now has a method
cookie to fetch the current cookie. One cookie has multiple crumbs which
represent a key value pair. For each crumb multiple options can be set
according to the specs.

6 files changed, 236 insertions, 6 deletions

diff --git a/lib/zero/response.rb b/lib/zero/response.rb
index ab4acde..cb58cfe 100644
--- a/lib/zero/response.rb
+++ b/lib/zero/response.rb
@@ -1,3 +1,5 @@
+require 'zero/response/cookie'
+
 module Zero
   # This is the representation of a response
   class Response
@@ -10,18 +12,17 @@ module Zero
 
     # Constructor
     # Sets default status code to 200.
-    #
     def initialize
       @status = 200
       @header = {}
       @body   = []
+      @cookies = {}
     end
 
     # Sets the status.
     # Also converts every input directly to an integer.
     #
     # @param [Integer] status The status code
-    #
     def status=(status)
       @status = status.to_i
     end
@@ -53,8 +54,8 @@ module Zero
     # Removes Content-Type, Content-Length and body on status code 204 and 304.
     #
     # @return [Array] Usable by webservers
-    #
     def to_a
+      add_cookie_headers
       # Remove content length and body, on status 204 and 304
       if status == 204 or status == 304
         header.delete('Content-Length')
@@ -72,7 +73,6 @@ module Zero
 
     # Sets the content length header to the current length of the body
     # Also creates one, if it does not exists
-    #
     def content_length
       self.header['Content-Length'] = body.join.bytesize.to_s
     end
@@ -81,7 +81,6 @@ module Zero
     # Also creates it, if it does not exists
     #
     # @param [String] value Content-Type tp set
-    #
     def content_type=(value)
       self.header['Content-Type'] = value
     end
@@ -89,10 +88,25 @@ module Zero
     # Sets the Location header to the given URL and the status code to 302.
     # 
     # @param [String] location Redirect URL
-    #
     def redirect(location, status = 302)
       self.status = status
       self.header['Location'] = location
     end
+
+    # get the cookie for the response
+    #
+    # This returns the cookie holding all crumbs for the response.
+    # @response [Cookie] the cookie with crumbs holding the information
+    def cookie
+      @cookie ||= Cookie.new
+    end
+
+    private
+
+    # merge the cookie header into the other headers
+    def add_cookie_headers
+      return unless @cookie
+      header.merge!(cookie.to_header)
+    end
   end
 end
diff --git a/lib/zero/response/cookie.rb b/lib/zero/response/cookie.rb
new file mode 100644
index 0000000..45ef65f
--- /dev/null
+++ b/lib/zero/response/cookie.rb
@@ -0,0 +1,105 @@
+module Zero
+  class Response
+    class Cookie
+      # initialize an empty cookie
+      def initialize
+        @crumbs = {}
+      end
+
+      # add a new crumb
+      #
+      # This adds a new crumb to the cookie specified through the key.
+      # @param key [String] the identifier for the crumb
+      # @param value [String] the value for the crumb
+      # @param options [Hash] hash with further options for the crumb
+      # @option options [Time]   :expire the time when the crumb should expire
+      # @option options [String] :domain the domain the crumb should be sent to
+      # @option options [String] :path   path when the crumb should be sent
+      # @option options [Array]  :flags set flags for :secure or :http_only
+      def add_crumb(key, value, options = {:flags => []})
+        @crumbs[key] = Crumb.new(key, value, options)
+      end
+
+      # get the crumb for the key
+      #
+      # This method returns the crumb for the specified key. The crumb holds all
+      # information, like the expire time and domain and so on.
+      # @param key [String] the key to return
+      # @returns [Cookie::Crumb] a cookie crumb or nil when the key
+      #                             does not exist
+      def get_crumb(key)
+        @crumbs[key]
+      end
+
+      # merge all crumbs to one header line
+      #
+      # This merges all crumbs together to a header line, where each cookie is
+      # separated by the `Set-Cookie` header.
+      # @returns [Hash] a key value pair to merge with the headers
+      def to_header
+        {'Set-Cookie' => @crumbs.map{|key, crumb| crumb}.join("\nSet-Cookie: ")}
+      end
+      
+      private
+
+      class Crumb
+        attr_reader :key, :secure, :http_only
+        attr_accessor :domain, :path, :expire, :value
+
+        def initialize(key, value, options = {})
+          options[:flags] ||= []
+          @key       = key
+          @value     = value
+          @domain    = options[:domain]
+          @expire    = options[:expire]
+          @path      = options[:path]
+          @secure    = options[:flags].include?(:secure)
+          @http_only = options[:flags].include?(:http_only)
+        end
+
+        # set the `http_only` flag
+        #
+        # This method sets the flag to only allow modifications from the
+        # server and makes the browser not allow modifications through
+        # javascript.
+        def deny_client_side_modification!
+          @http_only = true
+        end
+
+        # remove the `http_only` flag
+        #
+        # This removes the `http_only` flag to allow modifications of the
+        # crumb through javascript.
+        def allow_client_side_modification!
+          @http_only = false
+        end
+
+        # set the `secure` flag
+        #
+        # This sets the `secure` flag on the crumb which tells the browser to
+        # only send it through secure channels, like https.
+        # Keep in mind, that this does not encrypt the content of the Crumb!
+        def secure!
+          @secure = true
+        end
+
+        # unset the `secure` flag
+        #
+        # This unsets the `secure` flag which tells the browser, that it can
+        # send the crumb over unsecure channel too, like plain http.
+        def unsecure!
+          @secure = false
+        end
+
+        def to_s
+          "#{@key}=#{@value}" +
+            (@expire ? "; Expires=#{@expire.rfc2822}" : '') +
+            (@path   ? "; Path=#{@path}" : '') +
+            (@domain ? "; Domain=#{domain}" : '') +
+            (@http_only ? '; HttpOnly' : '') +
+            (@secure    ? '; Secure' : '')
+        end
+      end
+    end
+  end
+end
diff --git a/spec/unit/zero/response/cookie/add_crumb_spec.rb b/spec/unit/zero/response/cookie/add_crumb_spec.rb
new file mode 100644
index 0000000..3c8dbee
--- /dev/null
+++ b/spec/unit/zero/response/cookie/add_crumb_spec.rb
@@ -0,0 +1,54 @@
+require 'spec_helper'
+
+describe Zero::Response::Cookie, '#add_crumb' do
+  let(:cookie) { Zero::Response::Cookie.new }
+  subject { cookie.add_crumb(key, value, options) }
+  let(:options) { {} }
+  let(:key)     { 'key' }
+  let(:value)   { 'value' }
+
+  before :each do
+    subject
+  end
+
+  context 'with no argument' do
+    it 'adds a new crumb' do
+      expect(cookie.get_crumb(key).key).to be(key)
+    end
+  end
+
+  context 'with flags' do
+    let(:options) { {:flags => [:secure, :http_only]} }
+
+    it 'adds a crumb with secure header' do
+      expect(cookie.get_crumb(key).secure).to be(true)
+    end
+
+    it 'adds a crumb with http_only header' do
+      expect(cookie.get_crumb(key).http_only).to be(true)
+    end
+  end
+
+  context 'with expire' do
+    let(:time) { Time.now }
+    let(:options) { {:expire => time} }
+
+    it 'adds a crumb with expire header' do
+      expect(cookie.get_crumb(key).expire).to be(time)
+    end
+  end
+
+  context 'with domain and path' do
+    let(:domain) { 'libzero.org' }
+    let(:path)   { '/admin' }
+    let(:options) { {:domain => domain, :path => path} }
+
+    it 'adds a crumb with domain header' do
+      expect(cookie.get_crumb(key).domain).to be(domain)
+    end
+
+    it 'adds a crumb with path header' do
+      expect(cookie.get_crumb(key).path).to be(path)
+    end
+  end
+end
diff --git a/spec/unit/zero/response/cookie/get_crumb_spec.rb b/spec/unit/zero/response/cookie/get_crumb_spec.rb
new file mode 100644
index 0000000..3c315db
--- /dev/null
+++ b/spec/unit/zero/response/cookie/get_crumb_spec.rb
@@ -0,0 +1,21 @@
+require 'spec_helper'
+
+describe Zero::Response::Cookie, '#add_crumb' do
+  let(:cookie) { Zero::Response::Cookie.new }
+  subject { cookie.add_crumb(key, value, options) }
+  let(:options) { {} }
+  let(:key)     { 'key' }
+  let(:value)   { 'value' }
+
+  before :each do
+    subject
+  end
+
+  it 'returns the crumb when the crumb exists' do
+    expect(cookie.get_crumb(key).key).to be(key)
+  end
+
+  it 'returns nil for the wrong key' do
+    expect(cookie.get_crumb('wrong key')).to be(nil)
+  end
+end
diff --git a/spec/unit/zero/response/cookie/to_header_spec.rb b/spec/unit/zero/response/cookie/to_header_spec.rb
new file mode 100644
index 0000000..7cdc278
--- /dev/null
+++ b/spec/unit/zero/response/cookie/to_header_spec.rb
@@ -0,0 +1,29 @@
+require 'spec_helper'
+
+describe Zero::Response::Cookie, '#add_crumb' do
+  let(:cookie) { Zero::Response::Cookie.new }
+  subject { cookie.add_crumb(key, value, options) }
+  let(:options) { {
+    :domain => domain,
+    :path   => path,
+    :expire => time,
+    :flags  => flags
+  } }
+  let(:key)     { 'key' }
+  let(:value)   { 'value' }
+  let(:time)    { Time.new }
+  let(:domain)  { 'libzero.org' }
+  let(:path)    { '/admin' }
+  let(:flags)   { [:secure, :http_only] }
+
+  before :each do
+    subject
+  end
+
+  it 'returns the header line' do
+    expect(cookie.to_header).to eq(
+      {'Set-Cookie' => "#{key}=#{value}; Expires=#{time.rfc2822};" +
+                        " Path=#{path}; Domain=#{domain}; HttpOnly; Secure"}
+    )
+  end
+end
diff --git a/spec/unit/zero/response/to_a_spec.rb b/spec/unit/zero/response/to_a_spec.rb
index b016eb9..b547f98 100644
--- a/spec/unit/zero/response/to_a_spec.rb
+++ b/spec/unit/zero/response/to_a_spec.rb
@@ -69,5 +69,12 @@ describe Zero::Response do
       value[1].should eq({})  # Headers
       value[2].should eq([])  # Body
     end
+
+    it "adds the cookie to the headers" do
+      key = 'key'
+      value = 'value'
+      subject.cookie.add_crumb(key, value)
+      expect(subject.to_a[1]['Set-Cookie']).to eq("#{key}=#{value}")
+    end
   end
 end