react-native-gifted-chat/src/utils.js

import moment from 'moment';

export function isSameDay(currentMessage = {}, diffMessage = {}) {
  if (!diffMessage.createdAt) {
    return false;
  }

  const currentCreatedAt = moment(currentMessage.createdAt);
  const diffCreatedAt = moment(diffMessage.createdAt);

  if (!currentCreatedAt.isValid() || !diffCreatedAt.isValid()) {
    return false;
  }

  return currentCreatedAt.isSame(diffCreatedAt, 'day');
}

export function isSameUser(currentMessage = {}, diffMessage = {}) {
  return !!(diffMessage.user && currentMessage.user && diffMessage.user._id === currentMessage.user._id);
}