Error de decodificación de Swift: no se encontró la clave al decodificar JSON

Estoy decodificando una respuesta JSON en mi aplicación Swift, y el código decidió no funcionar cuando cambié la URL de API.

Esta es mi respuesta json

{
 "foodSearchCriteria":{
 "query":"eggs",
 "generalSearchInput":"eggs",
 "pageNumber":1,
 "numberOfResultsPerPage":50,
 "pageSize":50,
 "requireAllWords":false
 },
 "foods":[
 {
 "fdcId":577532,
 "description":"EGGS",
 "lowercaseDescription":"eggs",
 "dataType":"Branded",
 "gtinUpc":"021130049134",
 "publishedDate":"2019-04-01",
 "brandOwner":"Safeway, Inc.",
 "ingredients":"",
 "marketCountry":"United States",
 "foodCategory":"Eggs & Egg Substitutes",
 "modifiedDate":"2017-07-14",
 "dataSource":"LI",
 "servingSizeUnit":"g",
 "servingSize":44.0,
 "householdServingFullText":"1 EGG",
 "allHighlightFields":"",
 "score":848.0136,
 
 }

Me encuentro con este error.

Swift.DecodingError.keyNotFound(CodingKeys(stringValue: "foods", intValue: nil), Swift.DecodingError.Context(codingPath: [], debugDescription: "No value associated with key CodingKeys(stringValue: \"foods\", intValue: nil) (\"foods\").", underlyingError: nil))

Supuse que era porque no estaba haciendo coincidir mi var de "alimentos" correctamente, pero no aparece de esa manera. A continuación, adjunté fragmentos de mi llamada y estructuras.

 struct APISearchResults: Codable {
 let currentPage, totalPages: Int?
 let pageList: [Int]?
 //let foodSearchCriteria: FoodSearchCriteria
 let foods: [Food]
 
}
// MARK: - Food
struct Food: Codable { //core
 let fdcID: Int
 let foodDescription, lowercaseDescription, commonNames, additionalDescriptions: String?
 let dataType: String?
 let ndbNumber: Int?
 let publishedDate, foodCategory, allHighlightFields: String?
 let score: Double?
 let foodNutrients: [FoodNutrientInformation]
 let gtinUpc: Double?
 let brandOwner: String?
 let ingredients: String?
 let marketCountry: String?
 let modifiedDate: String?
 let dataSource: String?
 let servingSize: Double?
 let householdServingFullText: String?
 
 
 enum CodingKeys: String, CodingKey {
 case fdcID = "fdcId"
 case foodDescription = "description"
 case lowercaseDescription, commonNames, additionalDescriptions, dataType, ndbNumber, publishedDate, foodCategory, allHighlightFields, score, foodNutrients, gtinUpc, brandOwner, ingredients, marketCountry, modifiedDate, dataSource, servingSize, householdServingFullText
 }
}
// MARK: - FoodNutrient
struct FoodNutrientInformation: Codable {
 let nutrientID: Int?
 let nutrientName, nutrientNumber, unitName, derivationCode: String
 let derivationDescription: String?
 let derivationID: Int?
 let value: Double?
 let foodNutrientSourceID: Int?
 let foodNutrientSourceCode, foodNutrientSourceDescription: String?
 let rank, indentLevel, foodNutrientID, dataPoints: Int?
 enum CodingKeys: String, CodingKey {
 case nutrientID = "nutrientId"
 case nutrientName, nutrientNumber, unitName, derivationCode, derivationDescription
 case derivationID = "derivationId"
 case value
 case foodNutrientSourceID = "foodNutrientSourceId"
 case foodNutrientSourceCode, foodNutrientSourceDescription, rank, indentLevel
 case foodNutrientID = "foodNutrientId"
 case dataPoints
 }
}

Para fines de detalle, también adjuntaré la llamada API en sí misma en caso de que esté relacionada con eso.

class FoodApiSearch: ObservableObject{
 @Published var foodDescription = ""
 @Published var foodUnit = ""
 @Published var calories = ""
 
 //will search for user Input
 func searchFood(userItem: String){
 //calls api search
 guard let url = URL(string: "https://api.nal.usda.gov/fdc/v1/foods/search?api_key=***********?query=\(userItem)") else {return}
 
 URLSession.shared.dataTask(with: url) { (data, _,_) in
 let searchResults = try! JSONDecoder().decode(APISearchResults.self, from: data!)
 
 DispatchQueue.main.async {
 for item in searchResults.foods{
  self.foodDescription = item.lowercaseDescription?.firstCapitalized?? "food not valid"
  self.calories = String(Double(round(item.foodNutrients[3].value!)).removeZerosFromEnd())
 
  
  }
 
 }
 }
.resume()
 }
}

Solución del problema

Si tiene variables adicionales que no están decodificadas, debe incluir una codingKeysenumeración con solo el JSON que necesita decodificar. Su Codificable debe ser:

struct APISearchResults: Codable {
 var currentPage, totalPages: Int?
 var pageList: [Int]?
 //let foodSearchCriteria: FoodSearchCriteria
 let foods: [Food]
 enum CodingKeys: String, CodingKey {
 case foods
 }
}

El decodificador está buscando currentPage, totalPagesy pageListque no existen en el JSON. Cuando no incluye su propio codingKeys, el compilador los sintetiza, por lo que debe definirlos explícitamente en este caso.