Use retro gravatars for default avatars

app/decorators/helpers/avatar_helper.rb

@@ -7,18 +7,10 @@ module AvatarHelper
   private
 
   def avatar_url
-    gravatar_url || model.avatar_url || default_avatar_filename
-  end
-
-  def gravatar_url
-    return unless model.email.present?
-
-    hash = Digest::MD5.hexdigest(model.email.to_s.downcase)
-    "//gravatar.com/avatar/#{hash}?s=128"
-  end
-
-  def default_avatar_filename
-    h.image_path "default_avatar.png"
+    username = model.username || model.temporary_username || model.id
+    email = model.email || "#{username}@asciinema.org"
+    hash = Digest::MD5.hexdigest(email.downcase)
+    "//gravatar.com/avatar/#{hash}?s=128&d=retro"
   end
 
 end

db/migrate/20141129115837_remove_avatar_url_from_users.rb

@@ -0,0 +1,5 @@
+class RemoveAvatarUrlFromUsers < ActiveRecord::Migration
+  def change
+    remove_column :users, :avatar_url
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20141127112626) do
+ActiveRecord::Schema.define(version: 20141129115837) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -100,7 +100,6 @@ ActiveRecord::Schema.define(version: 20141127112626) do
     t.string   "uid"
     t.string   "email"
     t.string   "name"
-    t.string   "avatar_url"
     t.datetime "created_at",         null: false
     t.datetime "updated_at",         null: false
     t.string   "username"

spec/decorators/helpers/avatar_helper_spec.rb

@@ -3,39 +3,28 @@ require 'rails_helper'
 describe AvatarHelper do
 
   def expected_img(src)
-    %(<img alt="satyr" class="avatar" src="#{src}" />)
+    %(<img alt="satyr" class="avatar" src="#{src.gsub('&', '&amp;')}" />)
   end
 
   let(:decorator) { double('decorator', h: h, model: model).
                     extend(described_class) }
-  let(:model) { double('model', username: 'satyr', avatar_url: avatar_url,
-                                email: email) }
+  let(:model) { double('model', username: 'satyr', email: email) }
 
   describe '#avatar_image_tag' do
     subject { decorator.avatar_image_tag }
 
-    context "when user has an avatar_url" do
-      let(:avatar_url) { 'http://avatar/url' }
-
-      context "and user has an email" do
+    context "when user has an email" do
       let(:email) { 'foo@email.com' }
 
       it { should eq(expected_img(
-          '//gravatar.com/avatar/9dcfeb70fe212ea12562dddd22b0fc92?s=128')) }
+        '//gravatar.com/avatar/9dcfeb70fe212ea12562dddd22b0fc92?s=128&d=retro')) }
     end
 
-      context "and user has no email" do
+    context "when user has no email" do
       let(:email) { nil }
 
-        it { should eq(expected_img("http://avatar/url")) }
-      end
-    end
-
-    context "when user has neither email nor avatar_url" do
-      let(:email) { nil }
-      let(:avatar_url) { nil }
-
-      it { should eq(expected_img('/assets/default_avatar.png')) }
+      it { should eq(expected_img(
+        '//gravatar.com/avatar/9c0388ed63799af1e5f588e610851f0c?s=128&d=retro')) }
     end
   end