Merge branch 'master' into feature/gb/kubernetes-only-pipeline-jobs

* master: (275 commits)
  Decrease Metrics/PerceivedComplexity threshold to 17
  Upgrade mail and nokogiri gems due to security issues
  Link out to stackoverflow answer on setting swappiness
  Document swappiness recomendations in the requirements doc
  Fix invalid attribute used for time-ago-tooltip component
  Update latest artifacts doc
  Add changelog entry for flipping verify_certificates
  Default LDAP config verify_certificates to true
  Update share project with groups docs
  remove accidental console.log from karma tests
  update specs to match reorganized monitoring components
  Remove tooltips from new sidebar
  Use `git update-ref --stdin -z` to delete refs
  Don't use public_send in destroy_conditionally! helper
  Remove unused expressions policy from ci/cd config
  Simplify code for appending strategies in CI/CD config
  Raise exception when simplifiable ci entry incomplete
  Add changelog entry
  Fix MySQL failure for emoji autocomplete
  max-width for lazy-loaded images (this was removed in the original MR through merge resolution most probably)
  ...

Conflicts:
	lib/gitlab/ci/config/entry/policy.rb

1 files changed, 6 insertions, 2 deletions

diff --git a/lib/gitlab/ci/config/entry/simplifiable.rb b/lib/gitlab/ci/config/entry/simplifiable.rb
index c26576fcbcd..12764629686 100644
--- a/lib/gitlab/ci/config/entry/simplifiable.rb
+++ b/lib/gitlab/ci/config/entry/simplifiable.rb
@@ -6,6 +6,10 @@ module Gitlab
           EntryStrategy = Struct.new(:name, :condition)
 
           def initialize(config, **metadata)
+            unless self.class.const_defined?(:UnknownStrategy)
+              raise ArgumentError, 'UndefinedStrategy not available!'
+            end
+
             strategy = self.class.strategies.find do |variant|
               variant.condition.call(config)
             end
@@ -17,12 +21,12 @@ module Gitlab
 
           def self.strategy(name, **opts)
             EntryStrategy.new(name, opts.fetch(:if)).tap do |strategy|
-              (@strategies ||= []).append(strategy)
+              strategies.append(strategy)
             end
           end
 
           def self.strategies
-            @strategies.to_a
+            @strategies ||= []
           end
 
           def self.entry_class(strategy)