我提供了另一个答案，因为这里没有一个答案是针对从测试包加载资源的。如果您正在使用一个输出JSON的远程服务，并且希望在不触及实际服务的情况下对解析结果进行单元测试，则可以获取一个或多个响应，并将它们放入项目中的Tests文件夹中的文件中。

func testCanReadTestJSONFile() {
    let path = NSBundle(forClass: ForecastIOAdapterTests.self).pathForResource("ForecastIOSample", ofType: "json")
    if let jsonData = NSData(contentsOfFile:path!) {
        let json = JSON(data: jsonData)
        if let currentTemperature = json["currently"]["temperature"].double {
            println("json: \(json)")
            XCTAssertGreaterThan(currentTemperature, 0)
        }
    }
}

这也使用了SwiftyJSON，但获得测试包和加载文件的核心逻辑是问题的答案。

对于那些希望在decodedable抛出错误后在调试器/ lldb中打印JSON数据的人，请尝试以下方法。

阿宝试试!JSONSerialization。jsonObject(:数据!，选项:.mutableLeaves) as?字典<字符串,任何>

最新的swift 3.0绝对有效

func loadJson(filename fileName: String) -> [String: AnyObject]?
{
    if let url = Bundle.main.url(forResource: fileName, withExtension: "json") 
{
      if let data = NSData(contentsOf: url) {
          do {
                    let object = try JSONSerialization.jsonObject(with: data as Data, options: .allowFragments)
                    if let dictionary = object as? [String: AnyObject] {
                        return dictionary
                    }
                } catch {
                    print("Error!! Unable to parse  \(fileName).json")
                }
            }
            print("Error!! Unable to load  \(fileName).json")
        }
        return nil
    }

Swift 2.1答案(基于Abhishek):

    if let path = NSBundle.mainBundle().pathForResource("test", ofType: "json") {
        do {
            let jsonData = try NSData(contentsOfFile: path, options: NSDataReadingOptions.DataReadingMappedIfSafe)
            do {
                let jsonResult: NSDictionary = try NSJSONSerialization.JSONObjectWithData(jsonData, options: NSJSONReadingOptions.MutableContainers) as! NSDictionary
                if let people : [NSDictionary] = jsonResult["person"] as? [NSDictionary] {
                    for person: NSDictionary in people {
                        for (name,value) in person {
                            print("\(name) , \(value)")
                        }
                    }
                }
            } catch {}
        } catch {}
    }

一般的方法可以是这样的:

创建响应类名称字符串的json文件

struct Response: Codable,FileDecodable {
    typealias T = Self
    let names:[Data]
}
protocol FileDecodable{
   associatedtype T:Codable
   static func loadJson() ->T?
}

extension FileDecodable{
    static func loadJson() -> T? {
        let fileName = String(describing: T.self)
        if let url = Bundle.main.url(forResource: fileName, withExtension: "json")     {
            do {
                let data = try Data(contentsOf: url)
                let decoder = JSONDecoder()
                let jsonData = try decoder.decode(T.self, from: data)
                return jsonData
            } catch {
                print("error:\(error)")
            }
        }
        return nil
    }
}

Swift 3.0的更新名称

根据阿比谢克和德鲁瓦的回答

func loadJson(forFilename fileName: String) -> NSDictionary? {

    if let url = Bundle.main.url(forResource: fileName, withExtension: "json") {
        if let data = NSData(contentsOf: url) {
            do {
                let dictionary = try JSONSerialization.jsonObject(with: data as Data, options: .allowFragments) as? NSDictionary

                return dictionary
            } catch {
                print("Error!! Unable to parse  \(fileName).json")
            }
        }
        print("Error!! Unable to load  \(fileName).json")
    }

    return nil
}