Using Should().Equal() on two List<object> fails even though list contents are identical #1346
Description
Description
Using Should().Equal() to compare two List<object> always fails, even though the items in the list are equal. I have reproduced below with strings, and confirmed it is also true with ints.
Complete minimal example reproducing the issue
A reproducible example below. The exact same test but the type of the list goes
from List<string> to List<object>
// Two identical strings - should succeed
var strings = new List<string>{"foo"};
var identicalStrings = new List<string>{"foo"};
strings.Should().BeEquivalentTo(identicalStrings); // Passes
strings.Should().Equal(identicalStrings); // Passes
// Same test, but here the specified type is List<object>
var objects = new List<object>{"bar"};
var identicalObjects = new List<object>{"bar"};
objects.Should().BeEquivalentTo(identicalObjects); // Passes
objects.Should().Equal(identicalObjects); // This fails with
// Expected objects to be equal to {{"bar"}}, but {"bar"} differs at index 0.Full stack trace:
Error Message:
Expected objects to be equal to {{"bar"}}, but {"bar"} differs at index 0.
Stack Trace:
at FluentAssertions.Execution.XUnit2TestFramework.Throw(String message)
at FluentAssertions.Execution.TestFrameworkProvider.Throw(String message)
at FluentAssertions.Execution.DefaultAssertionStrategy.HandleFailure(String message)
at FluentAssertions.Execution.AssertionScope.FailWith(Func`1 failReasonFunc)
at FluentAssertions.Execution.AssertionScope.FailWith(Func`1 failReasonFunc)
at FluentAssertions.Execution.AssertionScope.FailWith(String message, Object[] args)
at FluentAssertions.Execution.GivenSelector`1.FailWith(String message, Object[] args)
at FluentAssertions.Execution.GivenSelector`1.FailWith(String message, Func`2[] args)
at FluentAssertions.Execution.GivenSelectorExtensions.AssertCollectionsHaveSameItems[TActual,TExpected](GivenSelector`1 givenSelector, ICollection`1 expected, Func`3 findIndex)
at FluentAssertions.Collections.CollectionAssertions`2.AssertSubjectEquality[TActual,TExpected](IEnumerable expectation, Func`3 equalityComparison, String because, Object[] becauseArgs)
at FluentAssertions.Collections.SelfReferencingCollectionAssertions`2.Equal(T[] elements)
at AIP.FastlogFG.Test.FastlogReaderRegresssionTets.FOO() in /home/geewee/programming/OAI/FastlogFG/FastlogFG.Test/FastlogReaderRegressionTests.cs:line 42
I have confirmed the same happens with List as List where the error looks similar: Expected objects to be equal to {{2}}, but {2} differs at index 0.
Note that strangely enough this snippet passes succesfully:
var objects = new List<object> {"foo"};
objects.Should().Equal("foo"); So it seems to only happen when comparing two List<object>
Versions
Fluent Assertion 5.10.3
.NET Core 3.1