新增：新合并请求列表接口

app/services/api/v1/projects/pulls/list_service.rb

@@ -0,0 +1,46 @@
+class Api::V1::Projects::Pulls::ListService < ApplicationService
+  include ActiveModel::Model
+
+  attr_reader :project, :keyword, :status, :priority_id, :issue_tag_id, :version_id, :reviewer_id, :sort_by, :sort_direction 
+  attr_accessor :queried_pull_requests
+
+  validates :status, inclusion: {in: [0, 1, 2], message: "请输入正确的Status"}, allow_nil: true
+  validates :sort_by, inclusion: {in: PullRequest.column_names, message: '请输入正确的SortBy'}
+  validates :sort_direction, inclusion: {in: %w(asc desc), message: '请输入正确的SortDirection'}
+
+  def initialize(project, params={})
+    @project = project 
+    @keyword = params[:keyword]
+    @status = params[:status].to_i
+    @priority_id = params[:priority_id]
+    @issue_tag_id = params[:issue_tag_id]
+    @version_id = params[:version_id]
+    @reviewer_id = params[:reviewer_id]
+    @sort_by = params[:sort_by] || 'created_at'
+    @sort_direction = params[:sort_direction] || 'desc'
+  end
+
+  def call 
+    raise Error, errors.full_messages.join(",") unless valid? 
+    pull_request_query_data
+
+    queried_pull_requests
+  end
+
+  private 
+  def pull_request_query_data 
+    pull_requests = @project.pull_requests
+
+    pull_requests = pull_requests.where(status: status) if status.present? 
+    pull_requests = pull_requests.where(issues: {priority_id: priority_id}) if priority_id.present?
+    pull_requests = pull_requests.where(issue_tags: {id: issue_tag_id}) if issue_tag_id.present? 
+    pull_requests = pull_requests.where(issues: {fixed_version_id: version_id}) if version_id.present?
+    pull_requests = pull_requests.where(users: {id: reviewer_id}) if reviewer_id.present? 
+    
+    q = pull_requests.ransack(title_or_body_cont: keyword)
+    scope = q.result.includes(:fork_project, :journals, :reviews, :reviewers, issue: [:journals, :priority, :version, :issue_tags])
+    scope = scope.order("pull_requests.#{sort_by} #{sort_direction}")
+
+    @queried_pull_requests = scope
+  end
+end