Add valid associations to epic_issue factory

EpicIssue records needs to be in the same
group hierarchy to be valid. If epic_issue
factory is not provided with an epic or an issue
the built associations need to be created
with this validation in mind.

ee/spec/factories/epic_issues.rb

@@ -2,8 +2,27 @@
 
 FactoryBot.define do
   factory :epic_issue do
-    epic
-    issue
+    transient do
+      epic { nil }
+      issue { nil }
+    end
+
     relative_position { RelativePositioning::START_POSITION }
+
+    after(:build) do |epic_issue, evaluator|
+      if evaluator.epic && evaluator.issue.nil?
+        epic_issue.epic = evaluator.epic
+        epic_issue.issue = create(:issue, project: create(:project, group: evaluator.epic.group))
+      elsif evaluator.issue && evaluator.epic.nil?
+        epic_issue.issue = evaluator.issue
+        epic_issue.epic = create(:epic, group: evaluator.issue.project.group)
+      elsif evaluator.issue.nil? && evaluator.epic.nil?
+        epic_issue.epic = create(:epic)
+        epic_issue.issue = create(:issue, project: create(:project, group: epic_issue.epic.group))
+      else
+        epic_issue.epic = evaluator.epic
+        epic_issue.issue = evaluator.issue
+      end
+    end
   end
 end