Add variables environment_scope scoped uniquness specs

spec/ee/spec/controllers/ee/projects/variables_controller_spec.rb

+require 'spec_helper'
+
+describe Projects::VariablesController do
+  let(:project) { create(:project) }
+  let(:user) { create(:user) }
+
+  before do
+    sign_in(user)
+    project.add_master(user)
+
+    allow_any_instance_of(License).to receive(:feature_available?).and_call_original
+    allow_any_instance_of(License).to receive(:feature_available?).with(:variable_environment_scope).and_return(true)
+  end
+
+  describe 'PATCH #update' do
+    let!(:variable) { create(:ci_variable, project: project) }
+    let(:owner) { project }
+
+    subject do
+      patch :update,
+        namespace_id: project.namespace.to_param,
+        project_id: project,
+        variables_attributes: variables_attributes,
+        format: :json
+    end
+
+    context 'with same key and different environment scope' do
+      let(:variable_attributes) do
+        { id: variable.id,
+          key: variable.key,
+          value: variable.value,
+          protected: variable.protected?.to_s,
+          environment_scope: variable.environment_scope }
+      end
+      let(:new_variable_attributes) do
+        { key: variable.key,
+          value: 'dummy_value',
+          protected: 'false',
+          environment_scope: 'prod' }
+      end
+      let(:variables_attributes) do
+        [
+          variable_attributes,
+          new_variable_attributes
+        ]
+      end
+
+      it 'does not update the existing variable' do
+        expect { subject }.not_to change { variable.reload.value }
+      end
+
+      it 'creates the new variable' do
+        expect { subject }.to change { owner.variables.count }.by(1)
+      end
+
+      it 'returns a successful response' do
+        subject
+
+        expect(response).to have_gitlab_http_status(:ok)
+      end
+
+      it 'has all variables in response' do
+        subject
+
+        expect(response).to match_response_schema('variables')
+      end
+    end
+  end
+end