plugins/optimization-test/src/main/resources/META-INF/cxs/rules/optimizationTest.json

{
    "metadata": {
        "id": "optimizationTest",
        "name": "optimizationTest",
        "description": "Copy variant id to session properties optimization_{optimizationId} = {variantId}"
    },
    "condition": {
      "parameterValues": {
        "eventTypeId": "optimizationTestEvent"
      },
      "type": "eventTypeCondition"
    },
    "actions": [
        {
          "parameterValues": {
            "setPropertyName": "script::'properties.optimizationTest_'+event.target.itemId",
            "setPropertyValue": "script::event.target.properties.variantId",
            "storeInSession": true
          },
          "type": "setPropertyAction"
        }
    ]
}