Refactor validation error messages

ee/lib/ee/gitlab/ci/config/entry/bridge.rb

@@ -38,10 +38,9 @@ module EE
 
               validate on: :composed do
                 next unless bridge_needs.present?
+                next if bridge_needs.one?
 
-                unless bridge_needs.one?
-                  errors.add(:config, 'should contain exactly one bridge need')
-                end
+                errors.add(:config, 'should contain at most one bridge need')
               end
             end
 

ee/spec/lib/ee/gitlab/ci/config/entry/bridge_spec.rb

@@ -199,7 +199,7 @@ describe EE::Gitlab::Ci::Config::Entry::Bridge do
 
       describe '#errors' do
         it 'returns an error about too many bridge needs' do
-          expect(subject.errors).to contain_exactly('bridge config should contain exactly one bridge need')
+          expect(subject.errors).to contain_exactly('bridge config should contain at most one bridge need')
         end
       end
     end

ee/spec/lib/gitlab/ci/config/entry/job_spec.rb

@@ -23,7 +23,7 @@ describe Gitlab::Ci::Config::Entry::Job do
 
           it 'returns error about invalid needs type' do
             expect(entry).not_to be_valid
-            expect(entry.errors).to contain_exactly('needs config uses bridge type(s)')
+            expect(entry.errors).to contain_exactly('needs config uses invalid types: bridge')
           end
         end
       end

lib/gitlab/ci/config/entry/needs.rb

@@ -22,7 +22,7 @@ module Gitlab
             validate on: :composed do
               extra_keys = value.keys - opt(:allowed_needs)
               if extra_keys.any?
-                errors.add(:config, "uses #{extra_keys.join(', ')} type(s)")
+                errors.add(:config, "uses invalid types: #{extra_keys.join(', ')}")
               end
             end
           end