c# - Why is AutoFixture executed more than once? -

i've been using autofixture / automoqdata / nunit several months now, quite happily far.

but i'm getting stuck on weird:

if want run single test in test suite (using testdriven), seems automoqdata attribute launched several times (between 5 , 9, don't know why, , decides how many times runs).

the problem if try freeze object instance in autofixture customizations, it'll end freezing 5 9 objects, using many fixture instances, , have no clue 1 injected in test.

is there way avoid ? why happen in first place ?

sample code :

public class automoqdataattribute : autodataattribute {     public automoqdataattribute()         : base(new fixture()             .customize(new automoqcustomization())             .customize(new frozenfoocustomization()) // freezing object             .customize(new frozenfixturecustomization()) // freezing passed fixture have fixture instance available in test body             .customize(new staticbindingcustomization()) // binding frozen object static reference             )     {     } }  public class frozenfoocustomization : icustomization {     public void customize(ifixture fixture)     {         fixture.freeze<foo>();     } }  public class foo { }  public class frozenfixturecustomization : icustomization {     public void customize(ifixture fixture)     {         fixture.inject(fixture);     } }  public class staticbindingcustomization : icustomization {     public void customize(ifixture fixture)     {         fixture.freeze<mock<isomeutilities>>();         var someutilities = fixture.create<mock<isomeutilities>>();         someutilities.setup(x => x.getstuff()).returns(fixture.create<foo>());         // executed several times, each time different instance of fixture, returning different instance of foo         someextensions.factory = x => someutilities.object;         // last "someutilities.object" bound factory, test relies on frozen version generated 1 of previous fixture instances     } }  [testfixture] public class test {     [test, automoqdata]     public void sometest(         [frozen]mock<isomeutilities> objmock,         someobjecttotest sut)     {         assert.istrue(referenceequals(objmock.object.getstuff(), sut.getstuff()));     } }  public class someobjecttotest { }  public static class someextensions {     public static func<object, isomeutilities> factory { get; set; } = x => new someutilities(x);      public static object getstuff(this object obj)     {         return factory(obj).getstuff();     } }  public class someutilities : isomeutilities {     private readonly object _obj;      public someutilities(object obj)     {         _obj = obj;     }      public object getstuff()     {         return _obj; // whatever     } }  public interface isomeutilities {     object getstuff(); } 

edit: someextensions.factory factory used make extensions mockable, based on daniel cazzulino's approach.

i'm not big fan of extensions , hope refactor them @ point, time. question here why there several fixture instances, making frozen someutilities mock used in factory different 1 used in test, , test fail.

edit2: following @markseemann's advice, reported issue on autofixture repo.