{
  "expression": ["==", null, ["get", "x"]],
  "inputs": [[{}, {"properties": {}}], [{}, {"properties": {"x": 1}}]],
  "expected": {
    "compiled": {
      "result": "success",
      "isFeatureConstant": false,
      "isZoomConstant": true,
      "type": "boolean"
    },
    "outputs": [true, false],
    "serialized": ["==", null, ["get", "x"]]
  }
}