I found the solution. We could do this using stubs
it "should return true for lead_reports if user is organization user" do
helper.stub(:params).and_return({action: 'lead_source'})
helper.stub(:is_org_user?).and_return(true)
expect(helper.show_sold_by_options?).to eq(true)
expect(helper).to have_received(:is_org_user?)
end
Please correct me if I did anything wrong.