Merge branch 'ee-stable-reviewer-roulette' into 'master'

Stable reviewer roulette

See merge request gitlab-org/gitlab-ee!10640

danger/roulette/Dangerfile

 # frozen_string_literal: true
 
+require 'digest/md5'
+
 MESSAGE = <<MARKDOWN
 ## Reviewer roulette
 
@@ -29,17 +31,22 @@ Please consider creating a merge request to
 for them.
 MARKDOWN
 
-def spin(team, project, category)
+def spin(team, project, category, branch_name)
+  rng = Random.new(Digest::MD5.hexdigest(branch_name).to_i(16))
+
   reviewers = team.select { |member| member.reviewer?(project, category) }
   traintainers = team.select { |member| member.traintainer?(project, category) }
   maintainers = team.select { |member| member.maintainer?(project, category) }
 
   # TODO: filter out people who are currently not in the office
+  # https://gitlab.com/gitlab-org/gitlab-ce/issues/57652
+  #
   # TODO: take CODEOWNERS into account?
+  # https://gitlab.com/gitlab-org/gitlab-ce/issues/57653
 
   # Make traintainers have triple the chance to be picked as a reviewer
-  reviewer = (reviewers + traintainers + traintainers).sample
-  maintainer = maintainers.sample
+  reviewer = (reviewers + traintainers + traintainers).sample(random: rng)
+  maintainer = maintainers.sample(random: rng)
 
   "| #{helper.label_for_category(category)} | #{reviewer&.markdown_name} | #{maintainer&.markdown_name} |"
 end
@@ -65,6 +72,12 @@ categories = changes.keys - [:unknown]
 # CSS Clean up MRs are reviewed using a slightly different process, so we
 # disable the review roulette for such MRs.
 if changes.any? && !gitlab.mr_labels.include?('single codebase') && !gitlab.mr_labels.include?('CSS cleanup')
+  # Strip leading and trailing CE/EE markers
+  canonical_branch_name = gitlab
+                            .mr_json['source_branch']
+                            .gsub(/^[ce]e-/, '')
+                            .gsub(/-[ce]e$/, '')
+
   team =
     begin
       helper.project_team
@@ -79,7 +92,7 @@ if changes.any? && !gitlab.mr_labels.include?('single codebase') && !gitlab.mr_l
   project = helper.project_name
   unknown = changes.fetch(:unknown, [])
 
-  rows = categories.map { |category| spin(team, project, category) }
+  rows = categories.map { |category| spin(team, project, category, canonical_branch_name) }
 
   markdown(MESSAGE)
   markdown(CATEGORY_TABLE_HEADER + rows.join("\n")) unless rows.empty?