Fix issue 11820 Add DirectoryExists() and FileExists() function

[huulinhnguyen-dev]

Fixes #
Fix the issue 11820, add two function DirectoryExists() and FileExists() #11820

Context

Currently, doesn't have any goodway to check the File or the Directory is exist or not, and the [System.IO.Directory]::Exists() is not allowed.

Changes Made

Add two function DirectoryExists() and FileExists() in the msbuild, now we can use [MSBuild]::FileExist() or [MSBuild]::DirectoryExists() in the project files

Testing

I have performed testing for various exception to validate the changes. Tested two case FileExists and DirectoryExist

Notes

[SimaTian]

Nice one. Thank you for your help.

[rainersigwald]

This looks like a good implementation, but my first instinct is to add [System.IO.Directory]::Exists(string), since that mirrors what we support today for files.

@KirillOsenkov, you asked for [MSBuild]::FileExists and [MSBuild]::DirectoryExists in #11820 (comment) though--you'd prefer this to enabling [System.IO.Directory]::Exists?

[KirillOsenkov]

I think we should have FileExists, DirectoryExists and [System.IO.Directory]::Exists too. It's strange that it's currently not available.

[KirillOsenkov]

👍

[rainersigwald]

Makes sense, I also favor "both/and".

@huulinh99, would you be interested in enabling Directory.Exists as part of this PR? It should be here:

msbuild/src/Build/Resources/Constants.cs

Lines 322 to 326 in 6de6474

	availableStaticMethods.TryAdd("System.IO.Directory::GetDirectories", directoryType);
	availableStaticMethods.TryAdd("System.IO.Directory::GetFiles", directoryType);
	availableStaticMethods.TryAdd("System.IO.Directory::GetLastAccessTime", directoryType);
	availableStaticMethods.TryAdd("System.IO.Directory::GetLastWriteTime", directoryType);
	availableStaticMethods.TryAdd("System.IO.Directory::GetParent", directoryType);

[huulinhnguyen-dev]

Hi @rainersigwald , thank you so much for your comment, I will enable Directory.Exists in this PR

[KirillOsenkov]

Quick question, will the syntax such as Condition="Exists('foo')" be supported? I'd like Condition="FileExists('foo')" and Condition="DirectoryExists('foo')" to work.

[rainersigwald]

I'd like Condition="FileExists('foo')" and Condition="DirectoryExists('foo')" to work.

That is entirely separate (😔) . . . but a reasonable request.

[KirillOsenkov]

wait, there are three syntaxes?

I guess ideally I was asking for the syntax without the ::

😅

[huulinhnguyen-dev]

Hi @rainersigwald @KirillOsenkov Could you confirm again that you are expecting both syntax Condition="$([System.IO.Directory]::Exists('foo'))" and Condition="DirectoryExists('foo')" to work well?

[KirillOsenkov]

Rainer says it's a separate mechanism, perhaps we can merge this PR and do that syntax separately, or do it as part of this PR, or not do it at all.

My apologies that the scope keeps increasing :)

Let's see what Rainer thinks. When I originally filed this issue, I wanted DirectoryExists() and FileExists() to complement the Exists() syntax, because that's the short and most natural one, and I'd love for this syntax to be used everywhere. I'm not sure how hard would it be to add support.

[rainersigwald]

Yeah we don't have to add any more functionality to this PR, let's merge with this (after adding the Directory.Exists test).

I would be happy for a follow-up PR to add the condition "functions" in FunctionCallExpressionNode.cs though!

[huulinhnguyen-dev]

Thank you for your comment @rainersigwald @KirillOsenkov , I will do base on your suggestion

[huulinhnguyen-dev]

@dotnet-policy-service agree

[rainersigwald]

Looks great, thanks!

[KirillOsenkov]

Thank you so much @huulinhnguyen-dev!