No tests found under net462

[blairconrad]

In FakeItEasy/FakeItEasy#2055, we migrated from Xbehave to LambdaTale and were very happy! Thanks for the tool.

Then we noticed that

No test is available in D:\a\FakeItEasy\FakeItEasy\tests\FakeItEasy.Specs\bin\Release\net462\FakeItEasy.Specs.dll. Make sure that test discoverer & executors are registered and platform & framework version settings are appropriate and try again.

And we've no idea why. We're stumped.

To help diagnose, we made the simplest repro we could think of: https://github.com/blairconrad/lambda-tail-net-462/tree/main

Help?

[CaringDev]

Hi @blairconrad
Thanks for your feedback. I'm looking into this...

Preliminary results:

• can reproduce using latest LambdaTale / xunit runner 2.4.3 (latest to suport net462)
• tests are discovered using net472 (for both xunit.runner.visualstudio 3.1.0 and 2.4.3)

[CaringDev]

@blairconrad Could you try the custom release for .NET 4.6.2?
Newer versions of LambdaTale should start working again once FakeItEasy Specs target .NET >= 4.7.1

I could not make LambdaTale work targeting netstandard2.0 or using xUnit > 2.9.0.
If you'd rather use a newer version now, I could raise an issue with xUnit.

[blairconrad]

Thanks for the speedy attention, @CaringDev. Much appreciated.

I grabbed bbv.LambdaTale 2.9.0-net462 and it worked perfectly for our net462 tests. Thanks!

Of course, I told you a simplified tale, and FakeItEasy actually targets

net462;netstandard2.0;netstandard2.1;net6.0;net8.0

and respectively tests on

net462;netcoreapp2.1;netcoreapp3.1;net6.0;net8.0

Using bbv.LambdaTale 2.9.0-net462 just for our net462 build and 2.9.302 otherwise worked like a charm.

Of course xUnit.net is moving away from some of the older TFMs, so our ability to continue to upgrade xUnit.net and LambdaTale could be fairly constrained in the future
(We'd had no plans to move to net471, nor make any changes/removals below net6.0 until things became too inconvenient; we may be approaching that point!)

@thomaslevesque and I will take the gift of the custom release and consider our options. Have a nice day!

[thomaslevesque]

@CaringDev thanks for looking into this!

In case it helps figure it out: the thing that broke it was really the switch itself from Xbehave to LambdaTale. If you look at this PR, in the first commit I just upgraded xUnit to satisfy LambdaTale's dependency constraints, then in the second commit I did the actual switch. After the first commit (so xUnit 2.9.3, still using Xbehave), the tests still worked. After switching to LambdaTale (no other change in that commit), it no longer worked for net462. So it's not an issue related to xUnit, as far as I can tell, but really a difference between Xbehave and LambdaTale.

[CaringDev]

@thomaslevesque thanks for your help!

I'll have to investigate further...

[CaringDev]

I suspected a problem with platform dependent runner assemblies, so added them back, still no luck: 2b1de88
But now, the breaking change is obvious: 3f6e33f

[thomaslevesque]

But now, the breaking change is obvious: 3f6e33f

Do you mean it works with xUnit 2.9.0, but not with 2.9.1?

It's odd. With Xbehave, it still worked with 2.9.3 🤔

[CaringDev]

Do you mean it works with xUnit 2.9.0, but not with 2.9.1?

Yes, that's my (and xUnits) understanding.

It's odd. With Xbehave, it still worked with 2.9.3 🤔

Maybe this has to do with Xbehave targeting netstandard1.1, which I bumped to netstandard2.0 for less #ifs and build warnings. In fact, I can reproduce this by selectively downgrading some of the xunit.* packages. However, if I check out e.g. latest Xbehave and update all xUnit to > 2.9.0 I face the same issues.

As I don't work with .NET Framework currently / anymore, I let that incompatibility slip in. Given the fact that 4.7.2 should be a "relatively easy" drop-in replacement, I'm willing to accept the inconvenience of breaking my unwritten support policy and "drop" 4.6.x, especially since it goes out of support by October.

Given the current state of affairs, I see the following options

• upgrade Spec tests from 4.6.2 to .NET 4.7.2
• keep using LambdaTale 2.9.0-net462 for net462 targets, eventually upgrade to LambdaTale.v3
• downgrade to Xbehave, eventually upgrade to LambdaTale.v3

In any case I'll

• release a new version of LambdaTale with correct (i.e. net8, net472) requirements (following xunit.runner.visualstudio)
• probably deprecate non-functional versions (i.e. everything pre-vNext 2.9.303)
• (re-)add .NET Framework tests on Windows

What do you think?

[thomaslevesque]

Maybe this has to do with Xbehave targeting netstandard1.1

Yeah, that seems plausible

What do you think?

Sounds like a good plan to me. I'll need to loop with @blairconrad, but I think upgrading our specs to net472 is a good option. And I just realized it doesn't even require us to drop net462 for the library itself (it will just be tested with a newer version).

[CaringDev]

The new .NET 8 / 4.7.2 version is available as 2.9.303-RC1.

Feel free to test; I'm going to test with some internal projects and will release the final version soonish, if there are no issues.

[CaringDev]

The new package is now available.
I wish you every success with the changeover (whichever option you choose).
If you encounter any problems, please let me know.