Xunit: Analyzer for MemberDataAttribute

[bradwilson]

_From @marcind on September 1, 2016 21:4_

Member specified by the attribute must be

• [x] public
• [x] static
• [x] property, field, or method
• [x] return something assignable to IEnumerable<object[]>
• [x] if no MemberType specified, member must be available on test class
  
  
  
  • [ ] unless class of test method is abstract (https://github.com/xunit/xunit/pull/967) and referencing xunit.core version 2.2.0 or later, in which case we'd want to verify concrete subclasses
  
  
• [x] if property, must have getter
• [ ] if method, arguments specified in attribute must be assignable to method parameters, and their count must match
• [x] if not method, attribute should not have parameters

This should probably be different rules, depending on implementation complexity

_Copied from original issue: xunit/xunit.analyzers#6_

[dhatrifork]

I want to use the pattern of #967, but it seems it is pending this issue? Maybe #967 should be reopened because it is not possible to run the example.

I am running the example from #967 (XUnitTestProject.zip):

using System;
using System.Collections.Generic;
using Xunit;

namespace XUnitTestProject
{
    public abstract class BaseClassWithTestWithoutData
    {
        [Theory]
        [MemberData("TestData")]
        public void Test(int data) { }
    }

    public class SubClassWithTestData : BaseClassWithTestWithoutData
    {
        public static IEnumerable<object[]> TestData()
        {
            yield return new object[] { 42 };
        }
    }
}

executed with dotnet xunit as explained in the documentation, I get the following:

$ dotnet xunit
Detecting target frameworks in XUnitTestProject.csproj...
Building for framework netcoreapp1.1...
UnitTest1.cs(10,10): error xUnit1015: MemberData must reference an existing member 'TestData' on type 'XUnitTestProject.BaseClassWithTestWithoutData'. [C:\Users\xxx\src\XUnitTestProject\XUnitTestProject\XUnitTestProject.csproj]
Build failed!

It also fails with the testrunner from VS2017.

Csproj-file looks like:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netcoreapp1.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.0.0" />
    <PackageReference Include="xunit" Version="2.3.0-beta3-build3705" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.3.0-beta3-build3705" />
    <DotNetCliToolReference Include="dotnet-xunit" Version="2.3.0-beta3-build3705" />
  </ItemGroup>

</Project>

[marcind]

You can disable the rule xUnit1015 until the problem gets fixed.

[ryanholden8]

Hi all,

Would love to use this pattern also.
It would cut down boilerplate code in every sub class.
However, I am also unable to use this pattern..

Running xUnit 2.4.1 on a .NET Core 2.1 project - disabling xUnit1015 results in the following exception:

System.NotSupportedException : Specified method is not supported.

Not sure if the work around does not work because it's a newer version of .NET Core?

The abstract class also makes use of generics, so maybe that is the issue?