未涵盖C#8.0单元测试开关表达式

我正在使用C#8.0，它支持我的项目中的开关表达式。我最近正在构建一个单元测试项目，并生成代码覆盖率报告。但是所有的开关表达式似乎都有问题。我的代码中有一些类似于以下内容的行：

private静态字符串生成器查询（语言，WeatherDataType数据类型）{
变量url=”https://data.weather.gov.hk/weatherAPI/opendata/weather.php?";
url+=语言开关{
Language.English=>“lang=en”，
Language.TraditionalChinese=>“lang=tc”，
Language.SimplifiedChinese=>“lang=sc”，
_=>“lang=en”
};
url+=数据类型开关{
WeatherDataType.LocalWeatherForecast=>“&dataType=flw”，
WeatherDataType.NineDaysWeather=>“&dataType=fnd”
};
返回url；
}

我的测试方法涵盖了上述所有情况，但报告显示，不包括带有开关表达式的行。如图所示：

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我应该怎么做才能覆盖它们。

虽然这可能不是您希望的答案，但代码覆盖似乎不适用于非顺序开关表达式

查看IL代码时，新的C#8.0开关表达式首先计算（跳转）哪个表达式为真，然后设置url。
而sequential switch语句在case语句之后设置url

因此，如果您想要全面覆盖，您应该使用sequential switch语句（如下面代码中的WeatherDataType）

代码

    .method public hidebysig static string  GenerateRequestUrl(valuetype Demo.Generator/Language language,
                                                           valuetype Demo.Generator/WeatherDataType dataType) cil managed
{
  // Code size       130 (0x82)
  .maxstack  2
  .locals init (string V_0,
           string V_1,
           string V_2,
           valuetype Demo.Generator/WeatherDataType V_3,
           valuetype Demo.Generator/WeatherDataType V_4,
           string V_5)
  IL_0000:  nop
  IL_0001:  ldstr      "https://data.weather.gov.hk/weatherAPI/opendata/we"
  + "ather.php\?"
  IL_0006:  stloc.0
  IL_0007:  ldloc.0
  IL_0008:  stloc.1
  IL_0009:  ldc.i4.1
  IL_000a:  brtrue.s   IL_000d
  IL_000c:  nop
  IL_000d:  ldarg.0
  IL_000e:  switch     ( 
                        IL_0021,
                        IL_0029,
                        IL_0031)
  IL_001f:  br.s       IL_0039
  IL_0021:  ldstr      "lang=en"
  IL_0026:  stloc.2
  IL_0027:  br.s       IL_0041
  IL_0029:  ldstr      "lang=tc"
  IL_002e:  stloc.2
  IL_002f:  br.s       IL_0041
  IL_0031:  ldstr      "lang=sc"
  IL_0036:  stloc.2
  IL_0037:  br.s       IL_0041
  IL_0039:  ldstr      "lang=en"
  IL_003e:  stloc.2
  IL_003f:  br.s       IL_0041
  IL_0041:  ldc.i4.1
  IL_0042:  brtrue.s   IL_0045
  IL_0044:  nop
  IL_0045:  ldloc.1
  IL_0046:  ldloc.2
  IL_0047:  call       string [System.Runtime]System.String::Concat(string,
                                                                    string)
  IL_004c:  stloc.0
  IL_004d:  ldarg.1
  IL_004e:  stloc.s    V_4
  IL_0050:  ldloc.s    V_4
  IL_0052:  stloc.3
  IL_0053:  ldloc.3
  IL_0054:  brfalse.s  IL_005e
  IL_0056:  br.s       IL_0058
  IL_0058:  ldloc.3
  IL_0059:  ldc.i4.1
  IL_005a:  beq.s      IL_006c
  IL_005c:  br.s       IL_007a
  IL_005e:  ldloc.0
  IL_005f:  ldstr      "&dataType=flw"
  IL_0064:  call       string [System.Runtime]System.String::Concat(string,
                                                                    string)
  IL_0069:  stloc.0
  IL_006a:  br.s       IL_007a
  IL_006c:  ldloc.0
  IL_006d:  ldstr      "&dataType=fnd"
  IL_0072:  call       string [System.Runtime]System.String::Concat(string,
                                                                    string)
  IL_0077:  stloc.0
  IL_0078:  br.s       IL_007a
  IL_007a:  ldloc.0
  IL_007b:  stloc.s    V_5
  IL_007d:  br.s       IL_007f
  IL_007f:  ldloc.s    V_5
  IL_0081:  ret
} // end of method Generator::GenerateRequestUrl

IL代码

    .method public hidebysig static string  GenerateRequestUrl(valuetype Demo.Generator/Language language,
                                                           valuetype Demo.Generator/WeatherDataType dataType) cil managed
{
  // Code size       130 (0x82)
  .maxstack  2
  .locals init (string V_0,
           string V_1,
           string V_2,
           valuetype Demo.Generator/WeatherDataType V_3,
           valuetype Demo.Generator/WeatherDataType V_4,
           string V_5)
  IL_0000:  nop
  IL_0001:  ldstr      "https://data.weather.gov.hk/weatherAPI/opendata/we"
  + "ather.php\?"
  IL_0006:  stloc.0
  IL_0007:  ldloc.0
  IL_0008:  stloc.1
  IL_0009:  ldc.i4.1
  IL_000a:  brtrue.s   IL_000d
  IL_000c:  nop
  IL_000d:  ldarg.0
  IL_000e:  switch     ( 
                        IL_0021,
                        IL_0029,
                        IL_0031)
  IL_001f:  br.s       IL_0039
  IL_0021:  ldstr      "lang=en"
  IL_0026:  stloc.2
  IL_0027:  br.s       IL_0041
  IL_0029:  ldstr      "lang=tc"
  IL_002e:  stloc.2
  IL_002f:  br.s       IL_0041
  IL_0031:  ldstr      "lang=sc"
  IL_0036:  stloc.2
  IL_0037:  br.s       IL_0041
  IL_0039:  ldstr      "lang=en"
  IL_003e:  stloc.2
  IL_003f:  br.s       IL_0041
  IL_0041:  ldc.i4.1
  IL_0042:  brtrue.s   IL_0045
  IL_0044:  nop
  IL_0045:  ldloc.1
  IL_0046:  ldloc.2
  IL_0047:  call       string [System.Runtime]System.String::Concat(string,
                                                                    string)
  IL_004c:  stloc.0
  IL_004d:  ldarg.1
  IL_004e:  stloc.s    V_4
  IL_0050:  ldloc.s    V_4
  IL_0052:  stloc.3
  IL_0053:  ldloc.3
  IL_0054:  brfalse.s  IL_005e
  IL_0056:  br.s       IL_0058
  IL_0058:  ldloc.3
  IL_0059:  ldc.i4.1
  IL_005a:  beq.s      IL_006c
  IL_005c:  br.s       IL_007a
  IL_005e:  ldloc.0
  IL_005f:  ldstr      "&dataType=flw"
  IL_0064:  call       string [System.Runtime]System.String::Concat(string,
                                                                    string)
  IL_0069:  stloc.0
  IL_006a:  br.s       IL_007a
  IL_006c:  ldloc.0
  IL_006d:  ldstr      "&dataType=fnd"
  IL_0072:  call       string [System.Runtime]System.String::Concat(string,
                                                                    string)
  IL_0077:  stloc.0
  IL_0078:  br.s       IL_007a
  IL_007a:  ldloc.0
  IL_007b:  stloc.s    V_5
  IL_007d:  br.s       IL_007f
  IL_007f:  ldloc.s    V_5
  IL_0081:  ret
} // end of method Generator::GenerateRequestUrl

---

升级您的测试框架和工具。我猜它不支持这些功能。您使用的是什么版本的Rider？我使用的是最新版本的Rider 2020.2.1如果您使用的是老式开关，测试是否通过？如果是，这是一个.NET Framework项目吗？如果是，您是否安装了所需的Nuget软件包？请提供一个最低限度的工作解决方案或到您的项目的github链接。这似乎是唯一的解决方案。非常感谢。