1 files changed, 117 insertions, 0 deletions
diff --git a/spec/graphql/resolvers/project_milestones_resolver_spec.rb b/spec/graphql/resolvers/project_milestones_resolver_spec.rb
new file mode 100644
index 00000000000..e0b250cfe7c
--- /dev/null
+++ b/spec/graphql/resolvers/project_milestones_resolver_spec.rb
@@ -0,0 +1,117 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Resolvers::ProjectMilestonesResolver do
+  include GraphqlHelpers
+
+  describe '#resolve' do
+    let_it_be(:project) { create(:project, :private) }
+    let_it_be(:current_user) { create(:user) }
+
+    before_all do
+      project.add_developer(current_user)
+    end
+
+    def resolve_project_milestones(args = {}, context = { current_user: current_user })
+      resolve(described_class, obj: project, args: args, ctx: context)
+    end
+
+    it 'calls MilestonesFinder to retrieve all milestones' do
+      expect(MilestonesFinder).to receive(:new)
+        .with(ids: nil, project_ids: project.id, state: 'all', start_date: nil, end_date: nil)
+        .and_call_original
+
+      resolve_project_milestones
+    end
+
+    context 'when including ancestor milestones' do
+      let(:parent_group) { create(:group) }
+      let(:group) { create(:group, parent: parent_group) }
+      let(:project) { create(:project, group: group) }
+
+      before do
+        project.add_developer(current_user)
+      end
+
+      it 'calls MilestonesFinder with correct parameters' do
+        expect(MilestonesFinder).to receive(:new)
+          .with(ids: nil, project_ids: project.id, group_ids: contain_exactly(group, parent_group), state: 'all', start_date: nil, end_date: nil)
+          .and_call_original
+
+        resolve_project_milestones(include_ancestors: true)
+      end
+    end
+
+    context 'by ids' do
+      it 'calls MilestonesFinder with correct parameters' do
+        milestone = create(:milestone, project: project)
+
+        expect(MilestonesFinder).to receive(:new)
+          .with(ids: [milestone.id.to_s], project_ids: project.id, state: 'all', start_date: nil, end_date: nil)
+          .and_call_original
+
+        resolve_project_milestones(ids: [milestone.to_global_id])
+      end
+    end
+
+    context 'by state' do
+      it 'calls MilestonesFinder with correct parameters' do
+        expect(MilestonesFinder).to receive(:new)
+          .with(ids: nil, project_ids: project.id, state: 'closed', start_date: nil, end_date: nil)
+          .and_call_original
+
+        resolve_project_milestones(state: 'closed')
+      end
+    end
+
+    context 'by timeframe' do
+      context 'when start_date and end_date are present' do
+        it 'calls MilestonesFinder with correct parameters' do
+          start_date = Time.now
+          end_date = Time.now + 5.days
+
+          expect(MilestonesFinder).to receive(:new)
+            .with(ids: nil, project_ids: project.id, state: 'all', start_date: start_date, end_date: end_date)
+            .and_call_original
+
+          resolve_project_milestones(start_date: start_date, end_date: end_date)
+        end
+
+        context 'when start date is after end_date' do
+          it 'raises error' do
+            expect do
+              resolve_project_milestones(start_date: Time.now, end_date: Time.now - 2.days)
+            end.to raise_error(Gitlab::Graphql::Errors::ArgumentError, "startDate is after endDate")
+          end
+        end
+      end
+
+      context 'when only start_date is present' do
+        it 'raises error' do
+          expect do
+            resolve_project_milestones(start_date: Time.now)
+          end.to raise_error(Gitlab::Graphql::Errors::ArgumentError, /Both startDate and endDate/)
+        end
+      end
+
+      context 'when only end_date is present' do
+        it 'raises error' do
+          expect do
+            resolve_project_milestones(end_date: Time.now)
+          end.to raise_error(Gitlab::Graphql::Errors::ArgumentError, /Both startDate and endDate/)
+        end
+      end
+    end
+
+    context 'when user cannot read milestones' do
+      it 'raises error' do
+        unauthorized_user = create(:user)
+
+        expect do
+          resolve_project_milestones({}, { current_user: unauthorized_user })
+        end.to raise_error(Gitlab::Graphql::Errors::ResourceNotAvailable)
+      end
+    end
+  end
+end