Improved code with dependencies injection.

LoadContentVC2.swift

class MyViewController: UIViewController {
   var myPath: String
   var content: [MyModel]
  
   // ...
   
  func loadContent(
     fileManager: FileManager, 
     path: String, 
     jsonDecoder: JSONDecoder = JSONDecoder()
  ) throws {    
    let data = fileManager.contents(atPath: path)
    self.content = try jsonDecoder.decode([MyModel].self, from data) 
  }
}