Simplify avatar lookup class

lib/avatar_lookup.rb

@@ -1,24 +1,19 @@
 class AvatarLookup
-  attr_accessor :user_ids, :users
 
   def initialize(user_ids=[])
-    self.user_ids = AvatarLookup.filtered_users(user_ids)
+    @user_ids = user_ids.tap(&:compact!).tap(&:uniq!)
   end
 
   # Lookup a user by id
   def [](user_id)
-    self.users = AvatarLookup.hashed_users(user_ids) if self.users.nil?
-    self.users[user_id]
+    users[user_id]
   end
 
   private
-  def self.filtered_users(user_ids=[])
-    user_ids.flatten.tap(&:compact!).tap(&:uniq!)
-  end
 
-  def self.hashed_users(user_ids=[])
-    users = User.where(:id => user_ids).select([:id, :email, :username])
-    users_with_ids = users.collect {|x| [x.id, x] }.flatten
-    Hash[*users_with_ids]
+  def users
+    @users ||= User.where(:id => @user_ids).select([:id, :email, :username]).inject({}) do |hash, user|
+      hash.merge({user.id => user})
+    end
   end
 end

spec/components/avatar_lookup_spec.rb

@@ -5,26 +5,10 @@
 
 describe AvatarLookup do
   let!(:user){ Fabricate(:user) }
-  user_ids = [1, 2]
-
-  describe '#new' do
-    before do
-      AvatarLookup.stubs(:filtered_users).once.returns(user_ids)
-      @avatar_lookup = AvatarLookup.new
-    end
-
-    it 'init with cleaned user ids' do
-      @avatar_lookup.user_ids.should eq(user_ids)
-    end
-
-    it 'init users hash' do
-      @avatar_lookup.users.should eq(nil)
-    end
-  end
 
   describe '#[]' do
     before do
-      @avatar_lookup = AvatarLookup.new([user.id])
+      @avatar_lookup = AvatarLookup.new([user.id, nil])
     end
 
     it 'returns nil if user_id does not exists' do
@@ -39,40 +23,4 @@
       @avatar_lookup[user.id].should eq(user)
     end
   end
-
-  describe '.filtered_users' do
-    it 'returns empty array if no params' do
-      AvatarLookup.filtered_users.should eq([])
-    end
-
-    it 'returns empty array' do
-      AvatarLookup.filtered_users([]).should eq([])
-    end
-
-    it 'returns filtered ids' do
-      AvatarLookup.filtered_users(user_ids).should eq(user_ids)
-    end
-
-    it 'returns flatten filtered ids' do
-      AvatarLookup.filtered_users([1, [2]]).should eq(user_ids)
-    end
-
-    it 'returns compact filtered ids' do
-      AvatarLookup.filtered_users([1, 2, nil]).should eq(user_ids)
-    end
-
-    it 'returns uniq filtered ids' do
-      AvatarLookup.filtered_users([1, 2, 2]).should eq(user_ids)
-    end
-  end
-
-  describe '.hashed_users' do
-    it 'returns empty hash if no params' do
-      AvatarLookup.hashed_users.should eq({})
-    end
-
-    it 'returns hashed users by id' do
-      AvatarLookup.hashed_users([user.id]).should eq({user.id => user})
-    end
-  end
 end