Call ignoreFile.IsIgnored with absolute path.

[nojaf]

I discovered that ignored files can potentially be formatted by Fantomas.Client.
Steps to reproduce:

• Clone https://github.com/dotnet/fsharp
• Run the following script:

#r "nuget: Fantomas.Client"

open System
open System.IO
open Fantomas.Client.Contracts
open Fantomas.Client.LSPFantomasService

let service = new LSPFantomasService() :> FantomasService

let file = @"C:\Users\nojaf\Projects\fsharp\src\Compiler\Checking\NicePrint.fs"
let content = File.ReadAllText file

let formatReq : FormatDocumentRequest = {
    SourceCode = content
    FilePath = file
    Config = None
}

service.FormatDocumentAsync(formatReq).Result.Code

The code will read 1 which means Formatted, you should receive 4 (Ignored) instead.

I believe I found a fix for this problem but I would like a review from @Smaug123 to be sure.

[nojaf]

@Smaug123 I believe the problem of using a relative path here is the following:
In loadIgnoreList we process the path with

fantomas/src/Fantomas/IgnoreFile.fs

Lines 54 to 58 in 47c6ac6

	let relativePath =
	fs
	.Path
	.GetRelativePath(fs.Directory.GetParent(ignoreFilePath).FullName, path)
	.Replace("\\", "/")

Looking at the docs, they mention GetFullPath is invoked before calculating the difference.

In the case of the cli tool, the relative will be resolved with the pwd because that is where we assume the ignore file lives. For the daemon, on the other hand, the pwd could be something really random and thus the difference is calculated wrongly.

Does this make sense to you?

[Smaug123]

Sigh, yeah, that does make sense. But might it be better to only pass fully-qualified paths?

[nojaf]

But might it be better to only pass fully-qualified paths?

Something like this?

[Smaug123]

Seems pretty plausible to me, although I can't say I am 100% confident.

[nojaf]

Thanks @Smaug123, I think this will be fine to try out.
As I've reported the issue myself, I don't think many people encounter this problem in the wild.

[Smaug123]

Yep, sounds sane to me!