lotus.module

<?php

/**
 * @file
 * Contains lotus.module.
 */

use Drupal\node\Entity\Node;

/**
 * Helper function to create a new node.
 */
function create_new_node(){
  $node = Node::create(['type' => 'YOUR_NODE_TYPE']);
  $node->set('title', 'YOUR_TITLE');

  //Body can now be an array with a value and a format.
  //If body field exists.
  $body = [
    'value' => 'YOUR_BODY_TEXT',
    'format' => 'basic_html',
  ];
  $node->set('body', $body);
  $node->set('uid', YOUR_UID);
  $node->status = 1;
  $node->enforceIsNew();
  $node->save();
  drupal_set_message("Node with nid " . $node->id() . " saved!\n");
}

Just a quick note: drupal_set_message() is deprecated since 8.5. Be sure to use \Drupal\Core\Messenger\MessengerInterface::addMessage() instead.

@mstekl
I agree, but you do realize this is an old gist :)

I do, but since it is linked from Aquia's documentation, I thought it might be worth the note in case other people ends on this old gist too :-)

Makes sense. Did not realize that this gist is linked.

I got this error InvalidArgumentException: Field body is unknown.