Refactor code and remove redundant code blocks

Remove the method `ssh_key_max_expiry_date` and associated
tests. Add "validate_" prefix to methods used for validating
models.

app/views/profiles/keys/_form.html.haml

-- max_date = ssh_key_max_expiry_date.to_date if ssh_key_expiration_policy_enabled?
+- max_date = ::Gitlab::CurrentSettings.max_ssh_key_lifetime_from_now.to_date if ssh_key_expiration_policy_enabled?
 %div
   = form_for [:profile, @key], html: { class: 'js-requires-input' } do |f|
     = form_errors(@key)

ee/app/helpers/ee/profiles_helper.rb

@@ -26,10 +26,6 @@ module EE
       License.feature_available?(:ssh_key_expiration_policy) && ::Feature.enabled?(:ff_limit_ssh_key_lifetime)
     end
 
-    def ssh_key_max_expiry_date
-      ::Gitlab::CurrentSettings.max_ssh_key_lifetime_from_now
-    end
-
     override :ssh_key_expiration_policy_enabled?
     def ssh_key_expiration_policy_enabled?
       ::Gitlab::CurrentSettings.max_ssh_key_lifetime && ssh_key_expiration_policy_licensed? && ::Feature.enabled?(:ff_limit_ssh_key_lifetime)

ee/app/models/ee/key.rb

@@ -15,7 +15,7 @@ module EE
       validate :expiration, if: -> { ::Key.expiration_enforced? }
 
       with_options if: :ssh_key_expiration_policy_enabled? do
-        validate :expires_at_before_max_expiry_date
+        validate :validate_expires_at_before_max_expiry_date
       end
 
       def expiration
@@ -32,12 +32,12 @@ module EE
         errors.map(&:type).reject { |t| t.eql?(:expired_and_enforced) }.empty?
       end
 
-      def expires_at_before_max_expiry_date
+      def validate_expires_at_before_max_expiry_date
         return errors.add(:key, message: 'has no expiration date but an expiration date is required for SSH keys on this instance. Contact the instance administrator.') if expires_at.blank?
 
         # when the key is not yet persisted the `created_at` field is nil
-        key_creation_date = created_at.presence || Time.current
-        errors.add(:key, message: 'has an invalid expiration date. Set a shorter lifetime for the key or contact the instance administrator.') if expires_at > key_creation_date + ::Gitlab::CurrentSettings.max_ssh_key_lifetime.days
+        max_expiry_date = (created_at.presence || Time.current) + ::Gitlab::CurrentSettings.max_ssh_key_lifetime.days
+        errors.add(:key, message: 'has an invalid expiration date. Set a shorter lifetime for the key or contact the instance administrator.') if expires_at > max_expiry_date
       end
     end
 

ee/spec/helpers/ee/profiles_helper_spec.rb

@@ -91,6 +91,7 @@ RSpec.describe ProfilesHelper do
       before do
         stub_feature_flags(ff_limit_ssh_key_lifetime: true)
       end
+
       context 'when is licensed and used' do
         before do
           stub_licensed_features(ssh_key_expiration_policy: true)
@@ -132,20 +133,4 @@ RSpec.describe ProfilesHelper do
       end
     end
   end
-
-  describe '#ssh_key_max_expiry_date' do
-    subject { helper.ssh_key_max_expiry_date }
-
-    context 'the instance has an expiry setting' do
-      before do
-        stub_application_setting(max_ssh_key_lifetime: 20)
-      end
-
-      it { is_expected.to be_like_time(20.days.from_now) }
-    end
-
-    context 'the instance does not have an expiry setting' do
-      it { is_expected.to be_nil }
-    end
-  end
 end

ee/spec/models/application_setting_spec.rb

@@ -819,7 +819,7 @@ RSpec.describe ApplicationSetting do
     end
   end
 
-  describe "#max_ssh_key_lifetime_from_now" do
+  describe "#max_ssh_key_lifetime_from_now", :freeze_time do
     subject { setting.max_ssh_key_lifetime_from_now }
 
     let(:days_from_now) { nil }

ee/spec/models/ee/key_spec.rb

@@ -23,7 +23,7 @@ RSpec.describe Key do
       end
     end
 
-    describe '#expires_at_before_max_expiry_date' do
+    describe '#validate_expires_at_before_max_expiry_date' do
       using RSpec::Parameterized::TableSyntax
 
       context 'for a range of key expiry combinations' do