Incorrect ElasticSearch mapping for JSON CustomFields

[shopwareBot]

Description:

A CustomField of "type" => CustomFieldTypes::JSON will be mapped to

[
    'type' => 'object',
    'dynamic' => true,
]

If the custom field is populated by a sw-entity-multi-id-select component, the fields value is, in fact, of type array (equally encodable to JSON).

The resulting error is:

Object mapping for [customFields.dummy_field] tried to parse field [null] as object, but found a concrete value"

Environment: Shopware 6.6.1 with OpenSearch 2.13.0

Steps to reproduce:

1. Install Shopware and setup OpenSearch in the specified versions
2. Create a demo plugin with a custom field using the following configuration:

   [
           'id' => md5('plugin_set'),
           'name' => 'cusom_set,
           'config' => [
               'label' => [
                   'de-DE' => 'Set',
                   'en-GB' => 'Set'
               ],
               'translated' => true
           ],
           'customFields' => [
               [
                   'id' => md5('plugin_field'),
                   'name' => 'custom_field',
                   'type' => CustomFieldTypes::JSON,
                   'config' => [
                       'type' => 'select',
                       'componentName' => 'sw-entity-multi-id-select',
                       'customFieldType' => CustomFieldTypes::JSON,
                       'entity' => 'product_manufacturer',
                       'value' => 'id',
                       'customFieldPosition' => 1
                   ],
               ],
           ],
           'relations' => [
               [
                   'id' => md5('custom_relation'),
                   'entityName' => 'product'
               ]
           ]
       ];

3. Install the demo plugin
4. Create a custom field of type sw-entity-multi-id-select on the product entity
5. Create a product and save a selection to the custom field

Expected result:

Product saves correctly and quietly.

Actual result:

Object mapping for [customFields.dummy_field] tried to parse field [null] as object, but found a concrete value"

Relevant parts of shopware code:

https://github.com/shopware/elasticsearch/blob/77159dc852765e6699622c1dc4eedfdc3ff3d8c9/Product/CustomFieldUpdater.php#L93

[shopware-issue-bot[bot]]

We found the following existing issues which may help or are related to your topic:

• Incorrect ElasticSearch mapping for JSON CustomFields
• Elasticsearch customFields
• ElasticsearchFieldMapper ignores customFieldMapping
• ElasticSearch fails while indexing boolean customFields
• Elastic Search Error when indexing custom fields
• customFields are not merged in Elasticsearch index
• Elasticsearch: customFields Fehler bei der Indexierung
• Elasticsearch indexing broken with custom field of type boolean
• Elasticsearch invalid date custom fields
• Elasticsearch/Opensearch: Custom field checkbox is parsed numeric

[shopwareBot]

[public] Automated response: This issue is linked to the internal issue https://shopware.atlassian.net/browse/NEXT-35565.

[created from NEXT-35565, comment 486436]