import { css } from "@emotion/core";
import React from "react";

checkNegative = counter => {
  if (counter) {
    return css`
      background: green;
    `;
  }
};

class Component extends React.Component {
  state = { counter: -1 };
  render() {
    return <div css={checkNegative(this.state.counter)}>some text</div>;
  }
}

export default Component;