1 files changed, 167 insertions, 0 deletions
diff --git a/spec/graphql/mutations/alert_management/alerts/set_assignees_spec.rb b/spec/graphql/mutations/alert_management/alerts/set_assignees_spec.rb
new file mode 100644
index 00000000000..a025b3d344a
--- /dev/null
+++ b/spec/graphql/mutations/alert_management/alerts/set_assignees_spec.rb
@@ -0,0 +1,167 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Mutations::AlertManagement::Alerts::SetAssignees do
+  let_it_be(:starting_assignee) { create(:user) }
+  let_it_be(:unassigned_user) { create(:user) }
+  let_it_be(:alert) { create(:alert_management_alert, assignees: [starting_assignee]) }
+  let_it_be(:project) { alert.project }
+
+  let(:current_user) { starting_assignee }
+  let(:assignee_usernames) { [unassigned_user.username] }
+  let(:operation_mode) { nil }
+
+  let(:args) do
+    {
+      project_path: project.full_path,
+      iid: alert.iid,
+      assignee_usernames: assignee_usernames,
+      operation_mode: operation_mode
+    }
+  end
+
+  before_all do
+    project.add_developer(starting_assignee)
+    project.add_developer(unassigned_user)
+  end
+
+  specify { expect(described_class).to require_graphql_authorizations(:update_alert_management_alert) }
+
+  describe '#resolve' do
+    let(:expected_assignees) { [unassigned_user] }
+
+    subject(:resolve) { mutation_for(project, current_user).resolve(args) }
+
+    shared_examples 'successful resolution' do
+      after do
+        alert.assignees = [starting_assignee]
+      end
+
+      it 'successfully resolves' do
+        expect(resolve).to eq(alert: alert.reload, errors: [])
+        expect(alert.assignees).to eq(expected_assignees)
+      end
+    end
+
+    shared_examples 'noop' do
+      it 'makes no changes' do
+        original_assignees = alert.assignees
+
+        expect(resolve).to eq(alert: alert.reload, errors: [])
+        expect(alert.assignees).to eq(original_assignees)
+      end
+    end
+
+    context 'when operation mode is not specified' do
+      it_behaves_like 'successful resolution'
+    end
+
+    context 'when user does not have permission to update alerts' do
+      let(:current_user) { create(:user) }
+
+      it 'raises an error if the resource is not accessible to the user' do
+        expect { subject }.to raise_error(Gitlab::Graphql::Errors::ResourceNotAvailable)
+      end
+    end
+
+    context 'for APPEND operation' do
+      let(:operation_mode) { Types::MutationOperationModeEnum.enum[:append] }
+
+      # Only allow a single assignee
+      context 'when a different user is already assigned' do
+        it_behaves_like 'noop'
+      end
+
+      context 'when no users are specified' do
+        let(:assignee_usernames) { [] }
+
+        it_behaves_like 'noop'
+      end
+
+      context 'when a user is specified and no user is assigned' do
+        before do
+          alert.assignees = []
+        end
+
+        it_behaves_like 'successful resolution'
+      end
+
+      context 'when the specified user is already assigned to the alert' do
+        let(:assignee_usernames) { [starting_assignee.username] }
+
+        it_behaves_like 'noop'
+      end
+    end
+
+    context 'for REPLACE operation' do
+      let(:operation_mode) { Types::MutationOperationModeEnum.enum[:replace] }
+
+      context 'when a different user is already assigned' do
+        it_behaves_like 'successful resolution'
+      end
+
+      context 'when no users are specified' do
+        let(:assignee_usernames) { [] }
+        let(:expected_assignees) { [] }
+
+        it_behaves_like 'successful resolution'
+      end
+
+      context 'when a user is specified and no user is assigned' do
+        before do
+          alert.assignees = []
+        end
+
+        it_behaves_like 'successful resolution'
+      end
+
+      context 'when the specified user is already assigned to the alert' do
+        let(:assignee_usernames) { [starting_assignee.username] }
+
+        it_behaves_like 'noop'
+      end
+
+      context 'when multiple users are specified' do
+        let(:assignees) { [starting_assignee, unassigned_user] }
+        let(:assignee_usernames) { assignees.map(&:username) }
+        let(:expected_assignees) { [assignees.last] }
+
+        it_behaves_like 'successful resolution'
+      end
+    end
+
+    context 'for REMOVE operation' do
+      let(:operation_mode) { Types::MutationOperationModeEnum.enum[:remove] }
+
+      context 'when a different user is already assigned' do
+        it_behaves_like 'noop'
+      end
+
+      context 'when no users are specified' do
+        let(:assignee_usernames) { [] }
+
+        it_behaves_like 'noop'
+      end
+
+      context 'when a user is specified and no user is assigned' do
+        before do
+          alert.assignees = []
+        end
+
+        it_behaves_like 'noop'
+      end
+
+      context 'when the specified user is already assigned to the alert' do
+        let(:assignee_usernames) { [starting_assignee.username] }
+        let(:expected_assignees) { [] }
+
+        it_behaves_like 'successful resolution'
+      end
+    end
+  end
+
+  def mutation_for(project, user)
+    described_class.new(object: project, context: { current_user: user }, field: nil)
+  end
+end