Hack for "AnyCodable" for encoding an array of generic structs.

anyCodableHack.swift

// https://stackoverflow.com/a/66697096/2006429

import Foundation

enum ChangeOp: String, Encodable {
  case replace
  case append
}

enum ChangePath: String, Encodable {
  case name = "/info/name"
  case number = "/info/number"
  case location = "/info/location"
  case showLocation = "/privacy/showLocation"
}

enum ChangeValue {
  case string(String)
  case int(Int)
  case stringArray([String])
  case bool(Bool)
}

extension ChangeValue: Encodable {
  func encode(to encoder: Encoder) throws {
    var container = encoder.singleValueContainer()
    switch self {
    case .string(let value):
      try container.encode(value)
    case .int(let value):
      try container.encode(value)
    case .stringArray(let value):
      try container.encode(value)
    case .bool(let value):
      try container.encode(value)
    }
  }
}

public struct UserChange: Encodable {
  let op: ChangeOp
  let path: ChangePath
  var value: ChangeValue

  enum CodingKeys: CodingKey {
    case op, path, value
  }
}

func encodeChanges(arr: [UserChange]) -> String? {
  let encoder = JSONEncoder()
  guard let jsonData = try? encoder.encode(arr) else {
    return nil
  }
  return String(data: jsonData, encoding: String.Encoding.utf8)
}

func requestUserChanges(changes: String) {
  print(changes)

  // make API request ...
}

requestUserChanges(changes:
  encodeChanges(arr: [
    UserChange(op: .replace, path: .name, value: .string("TestName")),
    UserChange(op: .replace, path: .number, value: .int(100)),
    UserChange(op: .replace, path: .location, value: .stringArray(["STATE", "CITY"])),
    UserChange(op: .replace, path: .showLocation, value: .bool(true)),
  ]) ?? "null"
)