{
  "expression": [
    "interpolate",
    ["exponential", 2],
    ["number", ["get", "x"]],
    1,
    ["literal", ["a"]],
    3,
    ["literal", ["b"]]
  ],
  "inputs": [],
  "expected": {
    "compiled": {
      "result": "error",
      "errors": [
        {"key": "", "error": "Type array<string, 1> is not interpolatable."}
      ]
    }
  }
}