Infer string type when using nameof pattern

[ntovas]

Most likely there is a better way to do this, any comment appreciated

Fixes: #13377

PS: I am a c# dev, it's my first time with f#, I would like to implement better (SynConst.String(c.ToString(), SynStringKind.Regular, m)) but I dont know how

[T-Gro]

Hi, had a look at the failing checks:

https://dev.azure.com/dnceng-public/public/_build/results?buildId=46781&view=logs&j=966222a4-f29d-5ec0-88cc-1b798728906e&t=052eabf8-67e2-5f29-745c-00cc34aa0e02 is hinting two failing tests related to this change:

at FSharp.Tests.Core.VersionTests.nameof-fsi() in D:\a_work\1\s\tests\fsharp\tests.fs:line 2102

and

at FSharp.Tests.Core.VersionTests.nameof-execute() in D:\a_work\1\s\tests\fsharp\tests.fs:line 2099

This should bring you to test cases where a new regression was introduced, please try to untackle this.
If it does not work, let me know and I can have a look later.

[ntovas]

@T-Gro
The tests seem to fail at PatternMatchingWithNameof, more specifically on the function:

let deserialize (e: RecordedEvent) : MyEvent =
        match e.EventType with
        | nameof A -> A e.Data
        | nameof B -> B e.Data
        | t -> failwithf "Invalid EventType: %s" t

Unfortunately, when I am running the same code with VisualFSharpDebug with targets: .net 7.0 - .net 4.7.2 it works as expected.
Am I missing something?

[T-Gro]

How did you run the same code please?
Depending on the test project, there might be "special" ways of launching the test suite - best to follow the readme.md in the /tests folder.

Or, alternatively, run Build.cmd with respective -test*** switch, this is what CI does.
(each CI report contains the cmd arguments used to launch it)

[ntovas]

Yes, I did that and in my local env it also fails.
I copied the same code in order to debug it and find the issue, so my main question is, how can I debug this case to find what is going wrong? I found no way to debug these test cases.

[T-Gro]

Yes, I did that and in my local env it also fails. I copied the same code in order to debug it and find the issue, so my main question is, how can I debug this case to find what is going wrong? I found no way to debug these test cases.

This specific is calling dotnet.exe with build /t:RunFSharpScript arguments => running a .fsx file.

[ntovas]

Ok, thanks, I look into this.

Update: Unfortunately I cannot solve this, the test continues to fail, but all the nameof resolutions seems to produce the correct const string. I don't have the required knowledge to find what is wrong :(
@T-Gro do you want me to close this MR?

[T-Gro]

Ok, thanks, I look into this.

Update: Unfortunately I cannot solve this, the test continues to fail, but all the nameof resolutions seems to produce the correct const string. I don't have the required knowledge to find what is wrong :( @T-Gro do you want me to close this MR?

Please keep it, I do want to have this working too.
I will try to start on it next milestone/month, and check how to troubleshoot that error.

I would love to help more, but from purely looking at it I do not have any ideas nor tips.

[T-Gro]

I think I got the issue now, will submit soon.

The Const.ToString() is a debug-oriented view, and therefore adds quotes around the string when rendering it.
That meant that within patterns, a nameof A was actually replaced with "A" , incl. the quotes in the string itself.

Which then meant that the pattern did not match.

I have also replaced the code to be more strict and insist on Const.String, since nameof should not produce any other constant type besides a string.

[psfinaki]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[psfinaki]

@ntovas thanks for the great first contribution :)
(and @T-Gro thanks for help)