1 files changed, 126 insertions, 0 deletions
diff --git a/spec/support/shared_examples/graphql/mutations/set_assignees_shared_examples.rb b/spec/support/shared_examples/graphql/mutations/set_assignees_shared_examples.rb
new file mode 100644
index 00000000000..cfa12171b7e
--- /dev/null
+++ b/spec/support/shared_examples/graphql/mutations/set_assignees_shared_examples.rb
@@ -0,0 +1,126 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.shared_examples 'an assignable resource' do
+  let_it_be(:user) { create(:user) }
+
+  subject(:mutation) { described_class.new(object: nil, context: { current_user: user }, field: nil) }
+
+  describe '#resolve' do
+    let_it_be(:assignee) { create(:user) }
+    let_it_be(:assignee2) { create(:user) }
+    let(:assignee_usernames) { [assignee.username] }
+    let(:mutated_resource) { subject[resource.class.name.underscore.to_sym] }
+
+    subject { mutation.resolve(project_path: resource.project.full_path, iid: resource.iid, assignee_usernames: assignee_usernames) }
+
+    before do
+      resource.project.add_developer(assignee)
+      resource.project.add_developer(assignee2)
+    end
+
+    it 'raises an error if the resource is not accessible to the user' do
+      expect { subject }.to raise_error(Gitlab::Graphql::Errors::ResourceNotAvailable)
+    end
+
+    context 'when the user can update the resource' do
+      before do
+        resource.project.add_developer(user)
+      end
+
+      it 'replaces the assignee' do
+        resource.assignees = [assignee2]
+        resource.save!
+
+        expect(mutated_resource).to eq(resource)
+        expect(mutated_resource.assignees).to contain_exactly(assignee)
+        expect(subject[:errors]).to be_empty
+      end
+
+      it 'returns errors when resource could not be updated' do
+        allow(resource).to receive(:errors_on_object).and_return(['foo'])
+
+        expect(subject[:errors]).not_to match_array(['foo'])
+      end
+
+      context 'when passing an empty assignee list' do
+        let(:assignee_usernames) { [] }
+
+        before do
+          resource.assignees = [assignee]
+          resource.save!
+        end
+
+        it 'removes all assignees' do
+          expect(mutated_resource).to eq(resource)
+          expect(mutated_resource.assignees).to eq([])
+          expect(subject[:errors]).to be_empty
+        end
+      end
+
+      context 'when passing "append" as true' do
+        subject do
+          mutation.resolve(
+            project_path: resource.project.full_path,
+            iid: resource.iid,
+            assignee_usernames: assignee_usernames,
+            operation_mode: Types::MutationOperationModeEnum.enum[:append]
+          )
+        end
+
+        before do
+          resource.assignees = [assignee2]
+          resource.save!
+
+          # In CE, APPEND is a NOOP as you can't have multiple assignees
+          # We test multiple assignment in EE specs
+          if resource.is_a?(MergeRequest)
+            stub_licensed_features(multiple_merge_request_assignees: false)
+          else
+            stub_licensed_features(multiple_issue_assignees: false)
+          end
+        end
+
+        it 'is a NO-OP in FOSS' do
+          expect(mutated_resource).to eq(resource)
+          expect(mutated_resource.assignees).to contain_exactly(assignee2)
+          expect(subject[:errors]).to be_empty
+        end
+      end
+
+      context 'when passing "remove" as true' do
+        before do
+          resource.assignees = [assignee]
+          resource.save!
+        end
+
+        it 'removes named assignee' do
+          mutated_resource = mutation.resolve(
+            project_path: resource.project.full_path,
+            iid: resource.iid,
+            assignee_usernames: assignee_usernames,
+            operation_mode: Types::MutationOperationModeEnum.enum[:remove]
+          )[resource.class.name.underscore.to_sym]
+
+          expect(mutated_resource).to eq(resource)
+          expect(mutated_resource.assignees).to eq([])
+          expect(subject[:errors]).to be_empty
+        end
+
+        it 'does not remove unnamed assignee' do
+          mutated_resource = mutation.resolve(
+            project_path: resource.project.full_path,
+            iid: resource.iid,
+            assignee_usernames: [assignee2.username],
+            operation_mode: Types::MutationOperationModeEnum.enum[:remove]
+          )[resource.class.name.underscore.to_sym]
+
+          expect(mutated_resource).to eq(resource)
+          expect(mutated_resource.assignees).to contain_exactly(assignee)
+          expect(subject[:errors]).to be_empty
+        end
+      end
+    end
+  end
+end