Add rspec for _button.html.haml

Added tests to test new logic in _button.html.haml

spec/views/projects/issues/import_csv/_button.html.haml_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'projects/issues/import_csv/_button' do
+  include Devise::Test::ControllerHelpers
+
+  context 'when the user is not an admin' do
+    before do
+      render
+    end
+
+    it 'shows a dropdown button to import CSV' do
+      expect(rendered).to have_text('Import CSV')
+    end
+
+    it 'does not show a button to import from Jira' do
+      expect(rendered).not_to have_text('Import from Jira')
+    end
+  end
+
+  context 'when the user is an admin' do
+    before do
+      allow(view).to receive(:can?).and_return(true)
+      allow(view).to receive(:project_import_jira_path).and_return('import/jira')
+
+      render
+    end
+
+    it 'shows a dropdown button to import CSV' do
+      expect(rendered).to have_text('Import CSV')
+    end
+
+    it 'shows a button to import from Jira' do
+      expect(rendered).to have_text('Import from Jira')
+    end
+  end
+end