Implement playlist edit feature

* Display playlists as links in index
* Move playlist form in a partial

app/controllers/playlists_controller.rb

@@ -15,4 +15,14 @@ class PlaylistsController < ApplicationController
       render :action => 'new'
     end
   end
+
+  def edit
+    @playlist = Playlist.find(params[:id])
+  end
+
+  def update
+    @playlist = Playlist.find(params[:id])
+    @playlist.update_attributes params[:playlist]
+    redirect_to :action => 'index'
+  end
 end

app/views/playlists/_form.html.haml

@@ -0,0 +1,4 @@
+= form_for @playlist do |f|
+  = f.label :name
+  = f.text_field :name
+  = f.submit submit_text

app/views/playlists/edit.html.haml

@@ -0,0 +1 @@
+= render 'form', :submit_text => 'Save'

app/views/playlists/index.html.haml

@@ -1,4 +1,5 @@
 = link_to 'Create playlist', new_playlist_path
 %ul
   - @playlists.each do |p|
-    %li= p.name
+    %li
+      = link_to p.name, edit_playlist_path(p)

app/views/playlists/new.html.haml

@@ -1,4 +1 @@
-= form_for @playlist do |f|
-  = f.label :name
-  = f.text_field :name
-  = f.submit 'Create'
+= render 'form', :submit_text => 'Create'

features/playlists.feature

@@ -16,3 +16,11 @@ Feature: Playlists
     And I fill in "Name" with "Electro"
     And I press "Create"
     Then I should see "Electro" within "ul>li"
+
+  Scenario: Edit playlist
+    Given a playlist named Electro
+    And I am on the playlists page
+    When I follow "Electro"
+    And I fill in "Name" with "Rock"
+    And I press "Save"
+    Then I should see "Rock"

features/step_definitions/playlists_step.rb

@@ -2,3 +2,7 @@ Given /^Foo and Bar playlists$/ do
   @foo = Playlist.create!(:name => 'Foo')
   @bar = Playlist.create!(:name => 'Bar')
 end
+
+Given /^a playlist named Electro$/ do
+  Playlist.create!(:name => 'Electro')
+end

spec/controllers/playlists_controller_spec.rb

@@ -7,7 +7,7 @@ describe PlaylistsController do
     }
   end
 
-  describe "GET index" do
+  describe 'GET index' do
     it 'assigns all playlists as @playlists' do
       playlist = Playlist.create! valid_attributes
       get :index
@@ -15,14 +15,22 @@ describe PlaylistsController do
     end
   end
 
-  describe "GET new" do
+  describe 'GET new' do
     it 'assigns a new playlist as @playlist' do
       get :new
       assigns[:playlist].should be_a_new(Playlist)
     end
   end
 
-  describe "POST create" do
+  describe 'GET edit' do
+    it 'assigns the requested playlist as @playlist' do
+      playlist = Playlist.create! valid_attributes
+      get :edit, :id => playlist.id.to_s
+      assigns[:playlist].should == playlist
+    end
+  end
+
+  describe 'POST create' do
     let(:playlist) { mock_model(Playlist).as_null_object }
 
     before do
@@ -64,4 +72,27 @@ describe PlaylistsController do
       end
     end
   end
+
+  describe 'PUT update' do
+    it 'updates the playlist' do
+      playlist = Playlist.create! valid_attributes
+      Playlist.any_instance.should_receive(:update_attributes).
+        with({'name' => 'Rock'})
+      put :update, :id => playlist.id.to_s, :playlist => {:name => 'Rock'}
+    end
+
+    it 'assigns the requested playlist as @playlist' do
+      playlist = Playlist.create! valid_attributes
+      put :update, :id => playlist.id.to_s, :playlist => {:name => 'Rock'}
+      assigns[:playlist].should == playlist
+    end
+
+    context 'when the playlist updates successfully' do
+      it 'redirects to the playlists index' do
+        playlist = Playlist.create! valid_attributes
+        put :update, :id => playlist.id.to_s, :playlist => valid_attributes
+        response.should redirect_to(:action => 'index')
+      end
+    end
+  end
 end

spec/views/playlists/edit.html.haml_spec.rb

@@ -0,0 +1,27 @@
+require 'spec_helper'
+
+describe 'playlists/edit.html.haml' do
+  let(:playlist) do
+    mock_model('Playlist').as_new_record.as_null_object
+  end
+
+  before do
+    assign :playlist, playlist
+  end
+
+  it 'renders a form to edit a playlist' do
+    render
+    rendered.should \
+      have_selector("form[method=post][action='#{playlists_path}']")
+    rendered.should have_selector('input[type=submit]')
+  end
+
+  it 'renders a text field with a label for the playlists name' do
+    playlist.stub(:name => 'Electro')
+    render
+    rendered.should \
+      have_selector("input[type=text][name='playlist[name]'][value=Electro]")
+    rendered.should \
+      have_selector("label[for=playlist_name]", :text => 'Name')
+  end
+end

spec/views/playlists/index.html.haml_spec.rb

@@ -3,20 +3,22 @@ require 'spec_helper'
 describe 'playlists/index.html.haml' do
   before do
     assign :playlists, [
-      double('Playlist', :name => 'Foo'),
-      double('Playlist', :name => 'Bar')
+      mock_model('Playlist', :name => 'Electro')
     ]
   end
 
   it 'displays a list of playlists' do
     render
-    rendered.should have_selector('ul>li', :count => 2)
-    rendered.should have_selector('ul>li', :text => 'Foo')
-    rendered.should have_selector('ul>li+li', :text => 'Bar')
+    rendered.should have_selector('ul>li', :text => 'Electro')
   end
 
   it 'displays a link to create a new playlist' do
     render
     rendered.should have_selector('a', :text => 'Create playlist')
   end
+
+  it 'displays playlists as links' do
+    render
+    rendered.should have_selector('a', :text => 'Electro')
+  end
 end