using PepLib.IO;
using Xunit;

namespace PepLib.Core.Tests.IO;

public class NestReaderTests
{
    [Fact]
    public void Read_ReadOnlyFile_DoesNotRequestWriteAccess()
    {
        // Arrange: a file on a read-only mount denies write-access opens (EROFS on Linux,
        // UnauthorizedAccessException on Windows when the read-only attribute is set).
        // NestReader only ever reads nest files, so it must never request FileAccess.Write.
        var path = Path.GetTempFileName();
        try
        {
            File.SetAttributes(path, FileAttributes.ReadOnly);

            var reader = new NestReader();

            // Act / Assert: opening must succeed (i.e. not throw because of the read-only
            // attribute). Parsing the empty/invalid content is expected to fail separately.
            var ex = Record.Exception(() => reader.Read(path));

            Assert.IsNotType<UnauthorizedAccessException>(ex);
        }
        finally
        {
            File.SetAttributes(path, FileAttributes.Normal);
            File.Delete(path);
        }
    }
}