Fix CI_COMMIT_REF_NAME and SLUG variable

With Pipelines for Merge Requests feature, users cannout keep using
$CI_COMMIT_REF_NAME and _SLUG predefined variables for dynamic
environments. We fix this problem by explicitly looking at the source
ref.

1 files changed, 21 insertions, 0 deletions

diff --git a/app/models/concerns/ci/pipeline_delegator.rb b/app/models/concerns/ci/pipeline_delegator.rb
new file mode 100644
index 00000000000..dbc5ed1bc9a
--- /dev/null
+++ b/app/models/concerns/ci/pipeline_delegator.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+##
+# This module is mainly used by child associations of `Ci::Pipeline` that needs to look up
+# single source of truth. For example, `Ci::Build` has `git_ref` method, which behaves
+# slightly different from `Ci::Pipeline`'s `git_ref`. This is very confusing as
+# the system could behave differently time to time.
+# We should have a single interface in `Ci::Pipeline` and access the method always.
+module Ci
+  module PipelineDelegator
+    extend ActiveSupport::Concern
+
+    included do
+      delegate :merge_request_event?,
+               :merge_request_ref?,
+               :source_ref,
+               :source_ref_slug,
+               :legacy_detached_merge_request_pipeline?, to: :pipeline
+    end
+  end
+end