Refactor project policy by removing duplicate declarations for readonly users.

Don't repeat declarations that are common between anonymous and auditor users.

app/policies/project_policy.rb

@@ -185,33 +185,12 @@ class ProjectPolicy < BasePolicy
 
   # An auditor user has read-only access to all projects
   def auditor_access!
-    can! :download_code
-    can! :download_wiki_code
-    can! :read_project
-    can! :read_board
-    can! :read_list
-    can! :read_wiki
-    can! :read_issue
-    can! :read_label
-    can! :read_milestone
-    can! :read_project_snippet
-    can! :read_project_member
-    can! :read_note
-    can! :read_cycle_analytics
-    can! :read_pipeline
-    can! :read_build
-    can! :read_commit_status
+    base_readonly_access!
+
     can! :read_build
-    can! :read_container_image
-    can! :read_pipeline
     can! :read_environment
     can! :read_deployment
-    can! :read_merge_request
     can! :read_pages
-    can! :read_commit_status
-    can! :read_pipeline
-    can! :read_container_image
-    can! :read_merge_request
   end
 
   def disabled_features!
@@ -260,25 +239,7 @@ class ProjectPolicy < BasePolicy
   def anonymous_rules
     return unless project.public?
 
-    can! :read_project
-    can! :read_board
-    can! :read_list
-    can! :read_wiki
-    can! :read_label
-    can! :read_milestone
-    can! :read_project_snippet
-    can! :read_project_member
-    can! :read_merge_request
-    can! :read_note
-    can! :read_pipeline
-    can! :read_commit_status
-    can! :read_container_image
-    can! :download_code
-    can! :download_wiki_code
-    can! :read_cycle_analytics
-
-    # NOTE: may be overridden by IssuePolicy
-    can! :read_issue
+    base_readonly_access!
 
     # Allow to read builds by anonymous user if guests are allowed
     can! :read_build if project.public_builds?
@@ -311,4 +272,31 @@ class ProjectPolicy < BasePolicy
       :"admin_#{name}"
     ]
   end
+
+  private
+
+  # A base set of abilities for read-only users, which
+  # is then augmented as necessary for anonymous and auditor
+  # users.
+  def base_readonly_access!
+    can! :read_project
+    can! :read_board
+    can! :read_list
+    can! :read_wiki
+    can! :read_label
+    can! :read_milestone
+    can! :read_project_snippet
+    can! :read_project_member
+    can! :read_merge_request
+    can! :read_note
+    can! :read_pipeline
+    can! :read_commit_status
+    can! :read_container_image
+    can! :download_code
+    can! :download_wiki_code
+    can! :read_cycle_analytics
+
+    # NOTE: may be overridden by IssuePolicy
+    can! :read_issue
+  end
 end