Obsolete Assert.Equals and add obsolete Assert.ReferenceEquals

[Copilot]

Changes Assert.Equals from throwing an exception to being marked as obsolete, and adds a new obsolete Assert.ReferenceEquals method. This prevents silent failures that would occur if these methods were removed entirely.

Problem

The original plan was to remove Assert.Equals in v4, but this would create a dangerous scenario:

// If Assert.Equals is removed, this code would silently call object.Equals()
// and never actually assert anything - a silent test failure!
Assert.Equals(expected, actual); // Falls back to object.Equals() - no assertion!

Solution

Instead of removal, both methods are now marked with [Obsolete] attributes:

• Assert.Equals: Now obsolete instead of throwing Assert.Fail()
• Assert.ReferenceEquals: New obsolete method to prevent similar issues

Both methods consistently return false and guide users to proper alternatives:

• Assert.Equals → Use Assert.AreEqual and overloads
• Assert.ReferenceEquals → Use Assert.AreSame and overloads

Implementation Details

• ✅ Modified Assert.Equals with [Obsolete] attribute
• ✅ Added new Assert.ReferenceEquals with [Obsolete] attribute
• ✅ Added DoNotUseAssertReferenceEquals resource string with full localization (13 languages)
• ✅ Updated PublicAPI.Unshipped.txt for new method
• ✅ Added unit tests to verify obsolete behavior
• ✅ Updated XML documentation

Testing

#pragma warning disable CS0618 // Type or member is obsolete
bool result1 = Assert.Equals("test", "test");        // Returns false, shows obsolete warning
bool result2 = Assert.ReferenceEquals(obj, obj);     // Returns false, shows obsolete warning  
#pragma warning restore CS0618 // Type or member is obsolete

This approach provides compile-time warnings while preventing the dangerous silent failure scenario.

Fixes #5758.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• 5rqvsblobprodcus385.vsblob.vsassets.io
  • Triggering command: /home/REDACTED/work/testfx/testfx/.dotnet/dotnet msbuild /m /nologo /clp:Summary /v:minimal /nr:true /warnaserror /p:TreatWarningsAsErrors=true /p:ContinuousIntegrationBuild=false /home/REDACTED/work/testfx/testfx/artifacts/toolset/restore.proj /t:__WriteToolsetLocation /clp:ErrorsOnly;NoSummary /p:__ToolsetLocationOutputFile=/home/REDACTED/work/testfx/testfx/artifacts/toolset/10.0.0-beta.25316.2.txt (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

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[Evangelink]

Please so the same job for StringAssert and CollectionAssert classes.

[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• 5rqvsblobprodcus385.vsblob.vsassets.io
  • Triggering command: /home/REDACTED/work/testfx/testfx/.dotnet/dotnet msbuild /m /nologo /clp:Summary /v:minimal /nr:true /warnaserror /p:TreatWarningsAsErrors=true /p:ContinuousIntegrationBuild=false /home/REDACTED/work/testfx/testfx/artifacts/toolset/restore.proj /t:__WriteToolsetLocation /clp:ErrorsOnly;NoSummary /p:__ToolsetLocationOutputFile=/home/REDACTED/work/testfx/testfx/artifacts/toolset/10.0.0-beta.25316.2.txt (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

[Copilot]

Please so the same job for StringAssert and CollectionAssert classes.

Done! Added obsolete Equals and ReferenceEquals methods to both StringAssert and CollectionAssert classes following the same pattern as Assert class - using constant string messages from FrameworkConstants and returning false to prevent silent failures. (b6650a9)

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• 5rqvsblobprodcus385.vsblob.vsassets.io
  • Triggering command: /home/REDACTED/work/testfx/testfx/.dotnet/dotnet msbuild /m /nologo /clp:Summary /v:minimal /nr:true /warnaserror /p:TreatWarningsAsErrors=true /p:ContinuousIntegrationBuild=false /home/REDACTED/work/testfx/testfx/artifacts/toolset/restore.proj /t:__WriteToolsetLocation /clp:ErrorsOnly;NoSummary /p:__ToolsetLocationOutputFile=/home/REDACTED/work/testfx/testfx/artifacts/toolset/10.0.0-beta.25316.2.txt (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

[Evangelink]

For all obsolete Equals and ReferenceEquals API, please instead of returning false ensuring we fail by calling the Assert.Fail API with a localized message.

[Copilot]

For all obsolete Equals and ReferenceEquals API, please instead of returning false ensuring we fail by calling the Assert.Fail API with a localized message.

Done! Changed all obsolete Equals and ReferenceEquals methods in Assert, StringAssert, and CollectionAssert to call Assert.Fail with localized messages instead of returning false. Added resource entries to FrameworkMessages.resx and all 13 xlf files, updated unit tests to expect AssertFailedException, and added comprehensive tests for all obsolete methods. (afb61d7)

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• 5rqvsblobprodcus385.vsblob.vsassets.io
  • Triggering command: /home/REDACTED/work/testfx/testfx/.dotnet/dotnet msbuild /m /nologo /clp:Summary /v:minimal /nr:true /warnaserror /p:TreatWarningsAsErrors=true /p:ContinuousIntegrationBuild=false /home/REDACTED/work/testfx/testfx/artifacts/toolset/restore.proj /t:__WriteToolsetLocation /clp:ErrorsOnly;NoSummary /p:__ToolsetLocationOutputFile=/home/REDACTED/work/testfx/testfx/artifacts/toolset/10.0.0-beta.25316.2.txt (dns block)
  • Triggering command: ./.dotnet/dotnet build src/TestFramework/TestFramework/TestFramework.csproj --no-restore --verbosity minimal (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list