Extracted from the closed PR #24539

Steps to Reproduce:

Run Microsoft.CodeAnalysis.CSharp.UnitTests.OverloadResolutionTests.GenericInferenceOnInErrTuples on a non-english machine.

Expected Behavior:

Test passes.

Actual Behavior:

Test fails for Diagnostics with a BoundTupleExpression because BoundTupleExpression.Display returns a localized string (e.g. German during the test run). BoundTupleExpression.Display should return a formattable string instead. There are some more tests that also fail. See the original PR for details.

History

The issue was discussed but not resolved in #24539. The relevant sections are:

@MaStr11
The diagnostic is created here and the argument is created via argument.Display
The problem here is that the BoundTupleExpression.Display uses a stringbuilder. So the argument is a text as opposed to a LocalizableErrorArgument. I don't see any straight forward way on how to resolve this. @AlekseyTs I would propose to revert my changes here and let the test fail on non english machines for now.

@AlekseyTs
It would be great if you could fix it because you can easily verify the effect, but it is up to you.
I think there is a simple fix for BoundTupleExpression.Display. Instead of building complete string, we can build a format string with argument markers and collect arguments in an array. Then we call to System.Runtime.CompilerServices.FormattableStringFactory.Create and return its result.
There is also an issue with

    internal partial class BoundStackAllocArrayCreation
    {
        public override object Display
        {
            get { return string.Format(MessageID.IDS_StackAllocExpression.Localize().ToString(), ElementType, Count.Syntax); }
        }
    }

This one can be fixed by creating an object that is very similar to LocalizableErrorArgument, that calls Format after getting the string for requested culture.