checkedKey function

dynamic checkedKey(
  1. Map<String, dynamic> json,
  2. String key
)

Reads a key that is required to be present in json but whose value may legitimately be null (OpenAPI 3.1 type: [T, "null"] combined with required). A plain json[key] as T? cast would otherwise accept a missing key as a null value, silently violating required. Throws FormatException when the key is absent.

Implementation

dynamic checkedKey(Map<String, dynamic> json, String key) {
  if (!json.containsKey(key)) {
    throw FormatException("Missing required key '$key'", json);
  }
  return json[key];
}