Require prop-types module.

Button.js

import React, { Component } from 'react';
import { StyleSheet, View, Text, TouchableHighlight } from 'react-native';
import PropTypes from 'prop-types';

/**
 * Color of underlayColor based themes
 */
const underlayColors = {
  primary: '#0062cc',
  secondary: '#545b62',
  success: '#1e7e34',
  danger: '#bd2130',
  warning: '#d39e00',
  info: '#117a8b',
  light: '#dae0e5',
  dark: '#1d2124',
  link: 'transparent'
};

/**
 * Name of available themes
 */
const themes = [
  'primary',
  'secondary',
  'success',
  'danger',
  'warning',
  'info',
  'light',
  'dark',
  'link'
];

export default class Button extends Component {
  static propTypes = {
    onPress: PropTypes.func.isRequired,
    text: PropTypes.string.isRequired,
    theme: PropTypes.oneOf(themes).isRequired
  }

  render() {
    return (
      <TouchableHighlight
        onPress={ this.props.onPress }
        style={ [styles.button, styles[this.props.theme]] }
        underlayColor={ underlayColors[this.props.theme] }>
        <Text style={ [styles.text, styles[`${this.props.theme}Text`]] }>
          { this.props.text.toUpperCase() }
        </Text>
      </TouchableHighlight>
    );
  }
}

/**
 * Styles for components
 */
const styles = StyleSheet.create({
  button: {
    alignItems: 'center',
    borderRadius: 2,
  },
  text: {
    paddingTop: 12,
    paddingBottom: 12,
    fontWeight: 'bold',
  },
  primary: {
    backgroundColor: '#007bff'
  },
  secondary: {
    backgroundColor: '#6c757d'
  },
  success: {
    backgroundColor: '#28a745'
  },
  danger: {
    backgroundColor: '#dc3545'
  },
  warning: {
    backgroundColor: '#ffc107'
  },
  info: {
    backgroundColor: '#17a2b8'
  },
  light: {
    backgroundColor: '#f8f9fa'
  },
  dark: {
    backgroundColor: '#343a40'
  },
  link: {
    backgroundColor: 'transparent'
  },
  primaryText: {
    color: '#ffffff'
  },
  secondaryText: {
    color: '#ffffff'
  },
  successText: {
    color: '#ffffff'
  },
  dangerText: {
    color: '#ffffff'
  },
  warningText: {
    color: '#212529'
  },
  infoText: {
    color: '#ffffff'
  },
  lightText: {
    color: '#212529'
  },
  darkText: {
    color: '#ffffff'
  },
  linkText: {
    color: '#007bff'
  },
});

quitaria esto

Button.propTypes = {
  onPress: PropTypes.func.isRequired,
  text: PropTypes.string.isRequired,
  theme: PropTypes.oneOf(themes).isRequired
}

y usaria static class properties

class Counter extends Component {
  static propTypes = {
    step: PropTypes.number.isRequired,
  }
}