[Multiple issue assignees] Fix issuable.assignee_or_author?

app/models/concerns/issuable.rb

@@ -342,11 +342,6 @@ module Issuable
     false
   end
 
-  def assignee_or_author?(user)
-    # We're comparing IDs here so we don't need to load any associations.
-    author_id == user.id || assignee_id == user.id
-  end
-
   def record_metrics
     metrics = self.metrics || create_metrics
     metrics.record!

app/models/issue.rb

@@ -139,6 +139,10 @@ class Issue < ActiveRecord::Base
     }
   end
 
+  def assignee_or_author?(user)
+    author_id == user.id || assignees.exists?(user)
+  end
+
   def assignee_list
     assignees.pluck(:name).join(', ')
   end

app/models/merge_request.rb

@@ -193,6 +193,10 @@ class MergeRequest < ActiveRecord::Base
     }
   end
 
+  def assignee_or_author?(user)
+    author_id == user.id || assignee_id == user.id
+  end
+
   # `from` argument can be a Namespace or Project.
   def to_reference(from = nil, full: false)
     reference = "#{self.class.reference_prefix}#{iid}"

app/services/issues/export_csv_service.rb

@@ -36,7 +36,7 @@ module Issues
        'Author' => 'author_name',
        'Author Username' => -> (issue) { issue.author&.username },
        'Assignee' => 'assignee_name',
-       'Assignee Username' => -> (issue) { issue.assignee&.username },
+       'Assignee Username' => -> (issue) { issue.assignee_list },
        'Confidential' => -> (issue) { issue.confidential? ? 'Yes' : 'No' },
        'Due Date' => -> (issue) { issue.due_date&.to_s(:csv) },
        'Created At (UTC)' => -> (issue) { issue.created_at&.to_s(:csv) },

spec/models/concerns/issuable_spec.rb

@@ -493,27 +493,6 @@ describe Issue, "Issuable" do
     end
   end
 
-  describe '#assignee_or_author?' do
-    let(:user) { build(:user, id: 1) }
-    let(:issue) { build(:issue) }
-
-    it 'returns true for a user that is assigned to an issue' do
-      issue.assignee = user
-
-      expect(issue.assignee_or_author?(user)).to eq(true)
-    end
-
-    it 'returns true for a user that is the author of an issue' do
-      issue.author = user
-
-      expect(issue.assignee_or_author?(user)).to eq(true)
-    end
-
-    it 'returns false for a user that is not the assignee or author' do
-      expect(issue.assignee_or_author?(user)).to eq(false)
-    end
-  end
-
   describe '#spend_time' do
     let(:user) { create(:user) }
     let(:issue) { create(:issue) }

spec/models/issue_spec.rb

@@ -132,6 +132,27 @@ describe Issue, models: true do
     end
   end
 
+  describe '#assignee_or_author?' do
+    let(:user) { create(:user) }
+    let(:issue) { create(:issue) }
+
+    it 'returns true for a user that is assigned to an issue' do
+      issue.assignees << user
+
+      expect(issue.assignee_or_author?(user)).to be_truthy
+    end
+
+    it 'returns true for a user that is the author of an issue' do
+      issue.update(author: user)
+
+      expect(issue.assignee_or_author?(user)).to be_truthy
+    end
+
+    it 'returns false for a user that is not the assignee or author' do
+      expect(issue.assignee_or_author?(user)).to be_falsey
+    end
+  end
+
   describe '#is_being_reassigned?' do
     it 'returns true if the issue assignee has changed' do
       subject.assignee = create(:user)

spec/models/merge_request_spec.rb

@@ -87,6 +87,26 @@ describe MergeRequest, models: true do
     end
   end
 
+  describe '#assignee_or_author?' do
+    let(:user) { build(:user) }
+
+    it 'returns true for a user that is assigned to a merge request' do
+      subject.assignee = user
+
+      expect(subject.assignee_or_author?(user)).to eq(true)
+    end
+
+    it 'returns true for a user that is the author of a merge request' do
+      subject.author = user
+
+      expect(subject.assignee_or_author?(user)).to eq(true)
+    end
+
+    it 'returns false for a user that is not the assignee or author' do
+      expect(subject.assignee_or_author?(user)).to eq(false)
+    end
+  end
+
   describe '#cache_merge_request_closes_issues!' do
     before do
       subject.project.team << [subject.author, :developer]