Retrieve the ProgramFilesX86 value by exclusively relying on System.Environment

[bbenoist]

Related documentation

• https://msdn.microsoft.com/en-us/library/system.environment.specialfolder.aspx
• http://stackoverflow.com/a/4514110

⚠️ Warning

As I am a newcomer on FAKE, please note that I did not tested the code more than that:

• I build it only on a 64-bit Windows using both build.cmd and FAKE.sln
• I only ran it to build my own (and private) source code.

IMHO, it might be careful to test this PR on every platform targeted by FAKE.

[forki]

did you encounter a bug or why do we need to change that?

[bbenoist]

Nope. In fact, I had recently encountered the same problematic and resolved it by using those 4 lines based only on .Net 😅

As I find the solution to be more maintainable (moves the detection to the .Net framework) and concise than making guesses on environment variables, I just wanted to inform you about such an alternative...

[forki]

I'm in favor of using the .NET stuff, but I don't remember why we have that hack. Maybe it's breaking...

[bbenoist]

Here are some commits affecting this function (from oldest to latest):

1. caa4733 Try to replace [ProgramFiles] and [ProgramFilesX86] in config file.
2. fea8435 Move ProgramFilesX86 into EnvironmentHelper.fs
3. b4e468e Using Path.Combine if possible.
4. 0ef901d Fixed issue Fake.Deploy fail investigation #49, Fake.Deploy failures.
5. 146945d Handle problems with ProgramFilesX86 on mono - Fix build of VSIX template fslaborg/zzarchive-FsLab#32

IMO, modifications of ProgramFilesX86 in 3 and 4 would have been unnecessary with an implementation relying on .Net. Only 5 seems to have interesting arguments against using the .Net way because it might throws exception on non-Windows platforms. However this can be managed with a proper try catch statement.

As I am not yet accustomed with Mono, there is something that I do not understand. What's the point of using ProgramFilesX86 outside of a Windows environment? Should'n it be avoided by throwing errors in such contexts?

[bbenoist]

Environment.cs - .NET Reference Source and Environment.cs - Mono answered my questions but have different behaviors when the information is unavailable.
Microsoft's implementation throws an exception whereas Mono's returns an empty string.

😢

[bbenoist]

cc @spouliot (79312b5)

[matthid]

All this stuff has changed anyway in the netcore version. I'll close this fow now. Feel free to send again against the new code.