1 files changed, 93 insertions, 0 deletions
diff --git a/spec/graphql/resolvers/design_management/version/design_at_version_resolver_spec.rb b/spec/graphql/resolvers/design_management/version/design_at_version_resolver_spec.rb
new file mode 100644
index 00000000000..cc9c0436885
--- /dev/null
+++ b/spec/graphql/resolvers/design_management/version/design_at_version_resolver_spec.rb
@@ -0,0 +1,93 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Resolvers::DesignManagement::Version::DesignAtVersionResolver do
+  include GraphqlHelpers
+
+  include_context 'four designs in three versions'
+
+  let(:current_user) { authorized_user }
+  let(:gql_context) { { current_user: current_user } }
+
+  let(:version) { third_version }
+  let(:design) { design_a }
+
+  let(:all_singular_args) do
+    {
+      design_at_version_id: global_id_of(dav(design)),
+      design_id: global_id_of(design),
+      filename: design.filename
+    }
+  end
+
+  shared_examples 'a bad argument' do
+    let(:err_class) { ::Gitlab::Graphql::Errors::ArgumentError }
+
+    it 'raises an appropriate error' do
+      expect { resolve_objects }.to raise_error(err_class)
+    end
+  end
+
+  describe '#resolve' do
+    describe 'passing combinations of arguments' do
+      context 'passing no arguments' do
+        let(:args) { {} }
+
+        it_behaves_like 'a bad argument'
+      end
+
+      context 'passing all arguments' do
+        let(:args) { all_singular_args }
+
+        it_behaves_like 'a bad argument'
+      end
+
+      context 'passing any two arguments' do
+        let(:args) { all_singular_args.slice(*all_singular_args.keys.sample(2)) }
+
+        it_behaves_like 'a bad argument'
+      end
+    end
+
+    %i[design_at_version_id design_id filename].each do |arg|
+      describe "passing #{arg}" do
+        let(:args) { all_singular_args.slice(arg) }
+
+        it 'finds the design' do
+          expect(resolve_objects).to eq(dav(design))
+        end
+
+        context 'when the user cannot see designs' do
+          let(:current_user) { create(:user) }
+
+          it 'returns nothing' do
+            expect(resolve_objects).to be_nil
+          end
+        end
+      end
+    end
+
+    describe 'attempting to retrieve an object not visible at this version' do
+      let(:design) { design_d }
+
+      %i[design_at_version_id design_id filename].each do |arg|
+        describe "passing #{arg}" do
+          let(:args) { all_singular_args.slice(arg) }
+
+          it 'does not find the design' do
+            expect(resolve_objects).to be_nil
+          end
+        end
+      end
+    end
+  end
+
+  def resolve_objects
+    resolve(described_class, obj: version, args: args, ctx: gql_context)
+  end
+
+  def dav(design)
+    build(:design_at_version, design: design, version: version)
+  end
+end