/// <summary>
/// Gets the absolute input path that contains the specified file or directory. If the provided
/// file or directory path is absolute, this returns the input path that contains the specified
/// path (note that the specified file or directory does not need to exist and this just returns
/// the input path that would contain the file or directory based only on path information). If
/// the provided path is relative, this checks all input paths for the existence of the file
/// or directory and returns the first one where it exists.
/// </summary>
/// <param name="fileSystem">The file system.</param>
/// <param name="path">The file path.</param>
/// <returns>The input path that contains the specified file,
/// or <c>null</c> if no input path does.</returns>
public static NormalizedPath GetContainingInputPath(this IReadOnlyFileSystem fileSystem, NormalizedPath path)
{
_ = fileSystem ?? throw new ArgumentNullException(nameof(fileSystem));
path.ThrowIfNull(nameof(path));
if (path.IsAbsolute)
{
return(fileSystem.GetContainingInputPathForAbsolutePath(path));
}
// Try to find a file first
IFile file = fileSystem.GetInputFile(path);
if (file.Exists)
{
return(fileSystem.GetContainingInputPath(file.Path));
}
// Then try to find a directory
IEnumerable <(NormalizedPath x, IDirectory)> rootDirectories =
fileSystem.InputPaths
.Reverse()
.Select(x => (x, fileSystem.GetRootDirectory(x.Combine(path))));
IEnumerable <(NormalizedPath x, IDirectory)> existingRootDirectories = rootDirectories.Where(x => x.Item2.Exists);
return(existingRootDirectories.Select(x => fileSystem.RootPath.Combine(x.Item1)).FirstOrDefault());
}