belongsTo used right

[fabstu]

Hello guys! After about a day of having a strange belongsTo error I got it to work! I found out that when fetching an associtation you can't name a foreign key and .forKey() (the associationKey == the name of the variable in the combined struct) the same... or that is my explanation for the error. Maybe add this in every belongsTo documentation 😆

Works:

public struct Session: FetchableRecord, Decodable, Equatable {
  public var session: SessionRecord
  public var bar: SessionBarRecord
  
  public init(
    session: SessionRecord,
    barID: SessionBarRecord
  ) {
    self.session = session
    self.bar = barID
  }
  
  enum CodingKeys: String, CodingKey {
    case session
    case bar
  }
  
  static func request(sessionID: SessionRecord.ID) -> QueryInterfaceRequest<Session> {
    
    return SessionRecord
      .including(required: SessionRecord.bar.forKey("bar"))
      .asRequest(of: Session.self)
  }
}

Crashes:

public struct Session: FetchableRecord, Decodable, Equatable {
  public var session: SessionRecord
  public var barID: SessionBarRecord
  
  public init(
    session: SessionRecord,
    barID: SessionBarRecord
  ) {
    self.session = session
    self.barID = barID
  }
  
  enum CodingKeys: String, CodingKey {
    case session
    case barID
  }
  
  static func request(sessionID: SessionRecord.ID) -> QueryInterfaceRequest<Session> {
    
    return SessionRecord
      .including(required: SessionRecord.bar.forKey("barID"))
      .asRequest(of: Session.self)
  }
}

Records:

public struct SessionRecord: Identifiable, Codable, Equatable, FetchableRecord, TableRecord, PersistableRecord {
  public static var databaseTableName: String { "Session" }

  static let bar = belongsTo(SessionBarRecord.self)
  
  public let id: String
  public let barID: SessionBarRecord.ID
  
  enum CodingKeys: String, CodingKey {
    case id
    case barID
  }
  
  public init(
    id: ID,
    barID: SessionBarRecord.ID
  ) {
    self.id = id
    self.barID = barID
  }
}

public struct SessionBarRecord: Identifiable, Codable, Equatable, FetchableRecord, TableRecord, PersistableRecord {
  public static var databaseTableName: String { "SessionBar" }
  
  public var id: String
  public let chosenLink: String?
  
  enum CodingKeys: String, CodingKey {
    case id
    case chosenLink
  }
  
  public init(
    id: ID,
    chosenLink: String?
  ) {
    self.id = id
    self.chosenLink = chosenLink
  }
}

The error I had:

error: Swift.DecodingError.dataCorrupted(Swift.DecodingError.Context(codingPath: [], debugDescription: "The given data was not valid JSON.", underlyingError: Optional(Error Domain=NSCocoaErrorDomain Code=3840 "Invalid value around line 1, column 0." UserInfo={NSDebugDescription=Invalid value around line 1, column 0., NSJSONSerializationErrorIndex=0})))

SessionBarRecords' decoder got called with a single value (the ID of the SessionBarRecord) instead of with a container of all its contents.