Move finder for merge request pipelines to Ci::

The existing MergeRequest::Pipelines finder class was
implemented under the MergeRequest module but it has a strong
Feature Envy towards Ci::Pipeline model.

app/finders/ci/pipelines_for_merge_request_finder.rb

+# frozen_string_literal: true
+
+module Ci
+  # A state object to centralize logic related to merge request pipelines
+  class PipelinesForMergeRequestFinder
+    include Gitlab::Utils::StrongMemoize
+
+    EVENT = 'merge_request_event'
+
+    def initialize(merge_request)
+      @merge_request = merge_request
+    end
+
+    attr_reader :merge_request
+
+    delegate :commit_shas, :source_project, :source_branch, to: :merge_request
+
+    def all
+      strong_memoize(:all_pipelines) do
+        next Ci::Pipeline.none unless source_project
+
+        pipelines =
+          if merge_request.persisted?
+            pipelines_using_cte
+          else
+            triggered_for_branch.for_sha(commit_shas)
+          end
+
+        sort(pipelines)
+      end
+    end
+
+    private
+
+    def pipelines_using_cte
+      cte = Gitlab::SQL::CTE.new(:shas, merge_request.all_commits.select(:sha))
+
+      source_pipelines_join = cte.table[:sha].eq(Ci::Pipeline.arel_table[:source_sha])
+      source_pipelines = filter_by(triggered_by_merge_request, cte, source_pipelines_join)
+      detached_pipelines = filter_by_sha(triggered_by_merge_request, cte)
+      pipelines_for_branch = filter_by_sha(triggered_for_branch, cte)
+
+      Ci::Pipeline.with(cte.to_arel) # rubocop: disable CodeReuse/ActiveRecord
+        .from_union([source_pipelines, detached_pipelines, pipelines_for_branch])
+    end
+
+    def filter_by_sha(pipelines, cte)
+      hex = Arel::Nodes::SqlLiteral.new("'hex'")
+      string_sha = Arel::Nodes::NamedFunction.new('encode', [cte.table[:sha], hex])
+      join_condition = string_sha.eq(Ci::Pipeline.arel_table[:sha])
+
+      filter_by(pipelines, cte, join_condition)
+    end
+
+    def filter_by(pipelines, cte, join_condition)
+      shas_table =
+        Ci::Pipeline.arel_table
+          .join(cte.table, Arel::Nodes::InnerJoin)
+          .on(join_condition)
+          .join_sources
+
+      pipelines.joins(shas_table) # rubocop: disable CodeReuse/ActiveRecord
+    end
+
+    # NOTE: this method returns only parent merge request pipelines.
+    # Child merge request pipelines have a different source.
+    def triggered_by_merge_request
+      source_project.ci_pipelines
+        .where(source: :merge_request_event, merge_request: merge_request) # rubocop: disable CodeReuse/ActiveRecord
+    end
+
+    def triggered_for_branch
+      source_project.ci_pipelines
+        .where(source: branch_pipeline_sources, ref: source_branch, tag: false) # rubocop: disable CodeReuse/ActiveRecord
+    end
+
+    def branch_pipeline_sources
+      strong_memoize(:branch_pipeline_sources) do
+        Ci::Pipeline.sources.reject { |source| source == EVENT }.values
+      end
+    end
+
+    def sort(pipelines)
+      sql = 'CASE ci_pipelines.source WHEN (?) THEN 0 ELSE 1 END, ci_pipelines.id DESC'
+      query = ApplicationRecord.send(:sanitize_sql_array, [sql, Ci::Pipeline.sources[:merge_request_event]]) # rubocop:disable GitlabSecurity/PublicSend
+
+      pipelines.order(Arel.sql(query)) # rubocop: disable CodeReuse/ActiveRecord
+    end
+  end
+end

app/models/merge_request.rb

@@ -1251,7 +1251,7 @@ class MergeRequest < ApplicationRecord
 
   def all_pipelines
     strong_memoize(:all_pipelines) do
-      MergeRequest::Pipelines.new(self).all
+      Ci::PipelinesForMergeRequestFinder.new(self).all
     end
   end
 

app/models/merge_request/pipelines.rb

-# frozen_string_literal: true
-
-# A state object to centralize logic related to merge request pipelines
-class MergeRequest::Pipelines
-  include Gitlab::Utils::StrongMemoize
-
-  EVENT = 'merge_request_event'
-
-  def initialize(merge_request)
-    @merge_request = merge_request
-  end
-
-  attr_reader :merge_request
-
-  delegate :commit_shas, :source_project, :source_branch, to: :merge_request
-
-  def all
-    strong_memoize(:all_pipelines) do
-      next Ci::Pipeline.none unless source_project
-
-      pipelines =
-        if merge_request.persisted?
-          pipelines_using_cte
-        else
-          triggered_for_branch.for_sha(commit_shas)
-        end
-
-      sort(pipelines)
-    end
-  end
-
-  private
-
-  def pipelines_using_cte
-    cte = Gitlab::SQL::CTE.new(:shas, merge_request.all_commits.select(:sha))
-
-    source_pipelines_join = cte.table[:sha].eq(Ci::Pipeline.arel_table[:source_sha])
-    source_pipelines = filter_by(triggered_by_merge_request, cte, source_pipelines_join)
-    detached_pipelines = filter_by_sha(triggered_by_merge_request, cte)
-    pipelines_for_branch = filter_by_sha(triggered_for_branch, cte)
-
-    Ci::Pipeline.with(cte.to_arel)
-      .from_union([source_pipelines, detached_pipelines, pipelines_for_branch])
-  end
-
-  def filter_by_sha(pipelines, cte)
-    hex = Arel::Nodes::SqlLiteral.new("'hex'")
-    string_sha = Arel::Nodes::NamedFunction.new('encode', [cte.table[:sha], hex])
-    join_condition = string_sha.eq(Ci::Pipeline.arel_table[:sha])
-
-    filter_by(pipelines, cte, join_condition)
-  end
-
-  def filter_by(pipelines, cte, join_condition)
-    shas_table =
-      Ci::Pipeline.arel_table
-        .join(cte.table, Arel::Nodes::InnerJoin)
-        .on(join_condition)
-        .join_sources
-
-    pipelines.joins(shas_table)
-  end
-
-  # NOTE: this method returns only parent merge request pipelines.
-  # Child merge request pipelines have a different source.
-  def triggered_by_merge_request
-    source_project.ci_pipelines
-      .where(source: :merge_request_event, merge_request: merge_request)
-  end
-
-  def triggered_for_branch
-    source_project.ci_pipelines
-      .where(source: branch_pipeline_sources, ref: source_branch, tag: false)
-  end
-
-  def branch_pipeline_sources
-    strong_memoize(:branch_pipeline_sources) do
-      Ci::Pipeline.sources.reject { |source| source == EVENT }.values
-    end
-  end
-
-  def sort(pipelines)
-    sql = 'CASE ci_pipelines.source WHEN (?) THEN 0 ELSE 1 END, ci_pipelines.id DESC'
-    query = ApplicationRecord.send(:sanitize_sql_array, [sql, Ci::Pipeline.sources[:merge_request_event]]) # rubocop:disable GitlabSecurity/PublicSend
-
-    pipelines.order(Arel.sql(query))
-  end
-end

spec/models/merge_request/pipelines_spec.rb → spec/finders/ci/pipelines_for_merge_request_finder_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-describe MergeRequest::Pipelines do
+describe Ci::PipelinesForMergeRequestFinder do
   describe '#all' do
     let(:merge_request) { create(:merge_request) }
     let(:project) { merge_request.source_project }