old_contents: import React, { PropTypes } from 'react';
  import EChart from './EChart';
  import SizeProvider from '../_common/SizeProvider';
  import createOptions from './options/MobileChartOptions';
  
  const theme = {
      background: 'white',
      line: 'rgba(42, 48, 82, 0.8)',
      fill: 'rgba(42, 48, 82, 0.2)',
      text: '#999',
      grid: '#eee',
      axisText: 'rgba(64, 68, 72, .5)',
  };
  
  export default class TradeChart extends React.Component {
  
      static propTypes = {
          history: PropTypes.array.isRequired,
          spot: PropTypes.number,
      };
  
      static defaultProps = {
          history: [],
          spot: 0,
      };
  
      render() {
          const { history, spot } = this.props;
          const options = createOptions({ history, spot: +spot, theme });
          return (
              <SizeProvider style={{ width: '100%', height: '120px' }}>
                  <EChart
                      options={options}
                      {...this.props}
                  />
              </SizeProvider>
          );
      }
  }
  
new_contents: import React, { PropTypes } from 'react';
  import EChart from './EChart';
  import SizeProvider from '../_common/SizeProvider';
  import createOptions from './options/MobileChartOptions';
  
  const theme = {
      background: 'white',
      line: 'rgba(42, 48, 82, 0.8)',
      fill: 'rgba(42, 48, 82, 0.2)',
      text: '#999',
      grid: '#eee',
      axisText: 'rgba(64, 68, 72, .5)',
  };
  
  export default class TradeChart extends React.Component {
  
      static propTypes = {
          history: PropTypes.array.isRequired,
          spot: PropTypes.number,
      };
  
      static defaultProps = {
          spot: 0,
      };
  
      render() {
          const { history, spot } = this.props;
          if (history.length === 0) return null;
          const options = createOptions({ history, spot: +spot, theme });
          return (
              <SizeProvider style={{ width: '100%', height: '120px' }}>
                  <EChart
                      options={options}
                      {...this.props}
                  />
              </SizeProvider>
          );
      }
  }
  
subject: Fix error when tick history is empty