Fixing tests when run on linux

Scripts/RunLinuxTests.ps1

@@ -1,7 +1,7 @@
 # running this seems to screw up the nuget restore, but provides a way to figure out why a test is failing on linux while working on windows.
 # you have to run this from the root, IE powershell ./Scripts/RunLinuxTests.ps1
 # also a lot of these tests fail due to line endings in your local files being \r\n but the writeLine using \n
-docker run --rm -v ${pwd}:/app -e "NormalizeLineEndings=1" -w /app/tests mcr.microsoft.com/dotnet/sdk:6.0 dotnet test /app/Src/CSharpier.Tests/CSharpier.Tests.csproj --logger:trx 
+docker run --rm -v ${pwd}:/app -e "NormalizeLineEndings=1" -w /app/tests mcr.microsoft.com/dotnet/sdk:7.0 dotnet test /app/Src/CSharpier.Tests/CSharpier.Tests.csproj --logger:trx
 
 # gross way to run csharpier against the csharpier-repos
 #docker run --rm -v ${pwd}:/app -e "NormalizeLineEndings=1" -w /app mcr.microsoft.com/dotnet/sdk:5.0 dotnet ./csharpier/Src/CSharpier/bin/Debug/net6.0/dotnet-csharpier.dll csharpier-repos --skip-write

Src/CSharpier.Tests/OptionsProviderTests.cs

@@ -438,6 +438,11 @@ private class TestContext
 
         public void WhenAFileExists(string path, string contents)
         {
+            if (!OperatingSystem.IsWindows())
+            {
+                path = path.Replace("c:", string.Empty);
+            }
+
             this.fileSystem.AddFile(path, new MockFileData(contents));
         }
 
@@ -446,6 +451,12 @@ public async Task<PrinterOptions> CreateProviderAndGetOptionsFor(
             string filePath
         )
         {
+            if (!OperatingSystem.IsWindows())
+            {
+                directoryName = directoryName.Replace("c:", string.Empty);
+                filePath = filePath.Replace("c:", string.Empty);
+            }
+
             this.fileSystem.AddDirectory(directoryName);
             var provider = await OptionsProvider.Create(
                 directoryName,