C＃为对象列表创建Mock Configuration.GetSection“ Section：SubSection”

如何解决C＃为对象列表创建Mock Configuration.GetSection“ Section：SubSection”

客观

使用Moq和XUnit创建一个模拟对象，以加载特定的“字符/技能”部分以增强单元测试的覆盖范围。

SUT（在某些情况下）以某种方式加载设置

var skills = Configuration.GetSection(“Character:Skills”);

通过以下appSetting：

{
    "dummyConfig1": {
        "Description": "bla bla bla...",},"Character": {
    "Name": "John Wick","Description": "A retired hitman seeking vengeance for the killing of the dog given to him...","Skills": [
        {
        "Key": "CQC Combat","Id": "15465"
        },{
        "Key": "Firearms","Id": "14321"
        },{
        "Key": "Stealth","Id": "09674"
        },{
        "Key": "Speed","Id": "10203"
        }
    ],"DummyConf2": "more bla bla bla..."
}

以前的阅读

在阅读这些文章（以及其他由于Googling导致的结果）时，我注意到我们只能使用原始的“字符串”数据类型，或者使用 new Mock 对象（无设置）：

约束：：将appSetting文件复制到TestProject（或创建MemoryStream）以加载实际设置可以解决这种情况，但是测试将是“集成”而不是“单元”；因为存在I / O依赖性。

方法

代码的想法（如下所示）是模拟每个属性（键/ id），然后将它们合并到类似于以下的树中：

“字符” ------要读取的配置，先使用GetSection()，然后使用Get<T>()
- “技能” ------具有合并属性的配置列表
  - “键”-“ CQC战斗” ------原始值1
  - “ Id”-“ 15465” ------原始值2

代码

var skillsConfiguration = new List<SkillsConfig>
{
    new SkillsConfig { Key = "CQC Combat",Id = "15465" },new SkillsConfig { Key = "Firearms",Id = "14321" },new SkillsConfig { Key = "Stealh",Id = "09674" },new SkillsConfig { Key = "Speed",Id = "10203" },};

var configurationMock = new Mock<IConfiguration>();
var mockConfSections = new List<IConfigurationSection>();

foreach (var skill in skillsConfiguration)
{
    var index = skillsConfiguration.IndexOf(skill);

    //Set the Key string value
    var mockConfSectionKey = new Mock<IConfigurationSection>();
    mockConfSectionKey.Setup(s => s.Path).Returns($"Character:Skills:{index}:Key");
    mockConfSectionKey.Setup(s => s.Key).Returns("Key");
    mockConfSectionKey.Setup(s => s.Value).Returns(skill.Key);

    //Set the Id string value
    var mockConfSectionId = new Mock<IConfigurationSection>();
    mockConfSectionId.Setup(s => s.Path).Returns($"Character:Skills:{index}:Id");
    mockConfSectionId.Setup(s => s.Key).Returns("Id");
    mockConfSectionId.Setup(s => s.Value).Returns(skill.Id);

    //Merge the attribute "key/id" as Configuration section list
    var mockConfSection = new Mock<IConfigurationSection>();                
    mockConfSection.Setup(s => s.Path).Returns($"Character:Skills:{index}");
    mockConfSection.Setup(s => s.Key).Returns(index.ToString());
    mockConfSection.Setup(s => s.GetChildren()).Returns(new List<IConfigurationSection> { mockConfSectionKey.Object,mockConfSectionId.Object });    
    
    //Add the skill object with merged attributes
    mockConfSections.Add(mockConfSection.Object);
}

// Add the Skill's list
var skillsMockSections = new Mock<IConfigurationSection>();
skillsMockSections.Setup(cfg => cfg.Path).Returns("Character:Skills");
skillsMockSections.Setup(cfg => cfg.Key).Returns("Skills");
skillsMockSections.Setup(cfg => cfg.GetChildren()).Returns(mockConfSections);

//Mock the whole section,for using GetSection() method withing SUT
configurationMock.Setup(cfg => cfg.GetSection("Character:Skills")).Returns(skillsMockSections.Object);

预期结果

运行原始系统，我得到了带有其各自实例的实例化列表这是屏幕截图：

模拟结果

上面的代码，我只得到实例化列表，但是所有属性都返回null。这是屏幕截图：

解决方法

最后，我重构了代码，摆脱了整个foreach块，并用下面的代码替换了列表初始化var mockConfSections = new List<IConfigurationSection>();，这更简单，更简洁。

var fakeSkillSettings = skillsConfiguration.SelectMany(
    skill => new Dictionary<string,string> {
        { $"Character:Skills:{skillsConfiguration.IndexOf(skill)}:Key",skill.Key },{ $"Character:Skills:{skillsConfiguration.IndexOf(skill)}:Id",skill.Id  },});

var configBuilder = new ConfigurationBuilder();
var mockConfSections = configBuilder.AddInMemoryCollection(fakeSkillSettings)
    .Build()
    .GetSection("Character:Skills")
    .GetChildren();

说明

由于先前的实现构建了带有模拟节点的配置树，因此需要为每个构建一个设置并返回，从而导致解决方案肿。

基于文章Keeping Configuration Settings in Memory，我使用LINQ SelectMany使用扁平化的Key / Id字典投影了列表，然后构建了内存配置，最后使用“真实节点”模拟了该设置，结果得到了一个模拟设置。