defaultProps doesn't work?

Expo Development Tools
1

The defaultProps static field is no longer working for me now that I’m migrating to CRNA. Please help me understand why this shows “test = undefined” instead of “test = true”. Thanks!

import React, { Component } from 'react';
import { View, Text, StyleSheet } from 'react-native';
import { Constants } from 'expo';
import { bool } from 'prop-types' // 15.6.0

class Test extends Component {
  static propTypes = {
    test: bool
  }
  static defaultProps = {
    test: true
  }

  render() {
    const { test } = this.props;
    return <Text>{'test = ' + test}</Text>;
  }
}

export default class App extends Component {
  render() {
    return (
      <View style={styles.container}>  
        <Test />
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    paddingTop: Constants.statusBarHeight,
    backgroundColor: '#ecf0f1',
  },
});