add emails method to GgpKey

app/models/gpg_key.rb

@@ -21,6 +21,11 @@ class GpgKey < ActiveRecord::Base
     write_attribute(:key, value)
   end
+  def emails
+    raw_key = GPGME::Key.get(fingerprint)
+    raw_key.uids.map(&:email)
+  end
+
   private
   def extract_fingerprint

spec/factories/gpg_keys.rb

+require_relative '../support/gpg_helpers'
+
+FactoryGirl.define do
+  factory :gpg_key do
+    key GpgHelpers.public_key
+  end
+end

spec/models/gpg_key_spec.rb

@@ -38,4 +38,12 @@ describe GpgKey do
       expect(described_class.new(key: " #{key} ").key).to eq(key)
     end
   end
+
+  describe '#emails' do
+    it 'returns the emails from the gpg key' do
+      gpg_key = create :gpg_key
+
+      expect(gpg_key.emails).to match_array %w(mail@koffeinfrei.org lex@panter.ch)
+    end
+  end
 end