sectionListGetItemLayout

sectionListGetItemLayout.jsx

import sectionListGetItemLayout from 'react-native-section-list-get-item-layout'

class MyComponent extends React.Component {
  constructor(props) {
    super(props)

    this.getItemLayout = sectionListGetItemLayout({
      // The height of the row with rowData at the given sectionIndex and rowIndex
      getItemHeight: (rowData, sectionIndex, rowIndex) => sectionIndex === 0 ? 100 : 50,

      // These three properties are optional
      getSeparatorHeight: () => 1 / PixelRatio.get(), // The height of your separators
      getSectionHeaderHeight: () => 20, // The height of your section headers
      getSectionFooterHeight: () => 10, // The height of your section footers
    })
  }

  render() {
    return (
      <SectionList
        {...otherStuff}
        getItemLayout={this.getItemLayout}
      />
    )
  }
}

There's a missing } for the wrapped object passed on to sectionListGetItemLayout.