Rewrite extension detection + add tests

app/models/asset.rb

@@ -8,7 +8,7 @@ class Asset < Sequel::Model
 
   PUBLIC_ATTRIBUTES = %w{ id public_url user_id kind }
 
-  VALID_EXTENSIONS = %w{ jpg gif png svg }
+  VALID_EXTENSIONS = %w{ .jpeg .jpg .gif .png .svg }
 
   attr_accessor :asset_file, :url
 
@@ -66,17 +66,19 @@ class Asset < Sequel::Model
     metadata = CartoDB::ImageMetadata.new(@file.path)
     errors.add(:file, "is too big, 1024x1024 max") if metadata.width > 1024 || metadata.height > 1024
     # If metadata reports no size, 99% sure not valid, so out
-    errors.add(:file, "doesn't appears to be an image") if metadata.width == 0 || metadata.height == 0
+    errors.add(:file, "doesn't appear to be an image") if metadata.width == 0 || metadata.height == 0
   rescue => e
     errors.add(:file, "error while uploading: #{e.message}")
   end
 
   def asset_file_extension
-    (asset_file.respond_to?(:original_filename) ? asset_file.original_filename : asset_file)
-      .split(".")
-      .last
-      .slice(0, 3) # Filename might include a postfix hash (e.g. Rack::Test::UploadedFile adds it)
-      .downcase
+    filename = asset_file.respond_to?(:original_filename) ? asset_file.original_filename : asset_file
+    extension = File.extname(filename).downcase
+
+    # Filename might include a postfix hash -- Rack::Test::UploadedFile adds it
+    extension.gsub!(/\d+-\w+-\w+\z/, '') if Rails.env.test?
+
+    extension if VALID_EXTENSIONS.include?(extension)
   end
 
   ##

spec/models/asset_spec.rb

@@ -35,7 +35,7 @@ describe Asset do
     it 'validates file correct metadata' do
       asset = Asset.new user_id: @user.id, asset_file: (Rails.root + 'spec/support/data/fake_png.png').to_s
       asset.valid?.should be_false
-      asset.errors.full_messages.should include("file doesn't appears to be an image")
+      asset.errors.full_messages.should include("file doesn't appear to be an image")
     end
 
     it 'validates file size' do

spec/requests/api/assets_spec.rb

@@ -53,6 +53,22 @@ describe "Assets API" do
     end
   end
 
+  it "finds image file extension" do
+    asset = FactoryGirl.create(:asset, user_id: $user_1.id)
+
+    Asset::VALID_EXTENSIONS.each do |extension|
+      asset_name = "cartofante" + extension
+      asset.stubs(:asset_file).returns(asset_name)
+      asset.asset_file_extension.should == extension
+    end
+  end
+
+  it "detects incorrect image file extension" do
+    asset = FactoryGirl.create(:asset, user_id: $user_1.id)
+    asset.stubs(:asset_file).returns("cartofante.gifv")
+    asset.asset_file_extension.should == nil
+  end
+
   it "deletes an asset" do
     FactoryGirl.create(:asset, user_id: $user_1.id)
     $user_1.reload