Step-definition for complex node structure (field collection + entity reference).

FeatureContext.php

<?php
 /**
   * @Given /^I am viewing a product with the following related products:$/
   */
  public function assertRelatedProducts(TableNode $relatedProducts) {
    // First, create a product.
    $product = (object) array(
      'title' => 'Parent Product',
      'type' => 'product',
      'uid' => 1,
    );
    $product = $this->getDriver()->createNode($product);

    // Create and reference related nodes.
    foreach ($relatedProducts->getHash() as $relatedProduct) {
      $relatedProduct = (object) $relatedProduct;
      $relatedProduct->type = 'product';
      $saved = $this->getDriver()->createNode($relatedProduct);
      $this->nodes[] = $saved;

      // Create field collection item.
      $fieldCollectionItem = entity_create('field_collection_item', array('field_name' => 'field_related_products'));
      $fieldCollectionItem->setHostEntity('node', $product);
      $fieldCollectionItem->field_product_reference[LANGUAGE_NONE][0]['target_id'] = $saved->nid;
      $fieldCollectionItem->field_is_component[LANGUAGE_NONE][0]['value'] = $relatedProduct->component;
      $fieldCollectionItem->save();
    }

    // Resave product node.
    node_save($product);
    $this->nodes[] = $product;

    // Set internal page on the product.
    $this->getSession()->visit($this->locatePath('/node/' . $product->nid));
  }
}

foo.feature

Scenario: Related products and components
  Given I am viewing a product with the following related products:
  | title               | component |
  | Related product 1   |         0 |
  | Related product 2   |         0 |
  | Related component 1 |         1 |
  | Related component 2 |         1 |
  Then I should see the heading "Related Products"
  And I should see the link "Related product 1"
  And I should see the link "Related product 2"
  And I should see the link "Related component 1"
  And I should see the link "Related component 2"

Hey jhedstrom, Thanks so much for this, I keep receiving a message of The "field_collection_item" entity type does not exist. (Drupal\Component\Plugin\Exception\PluginNotFoundException) when running this test, am I missing something?

@bennyc2444 you need to install this module https://www.drupal.org/project/field_collection and I think you need to create all entity type used in this example.