Opening local files not working

[jiri-matejka]

When I open file with absolute path, I get InvalidOperationException: Unsupported scheme: file.
I am using Linux.

This happens because your logic for opening files is problematic:

try
{
    var uri = new Uri(options.Url);
    
    switch (uri.Scheme)
    {
        case "http":
        case "https":
        case "ws":
        case "wss":
            _type = _options.ReplicaPath != null ? DatabaseType.EmbeddedReplica : DatabaseType.Remote;
            break;
        default:
            throw new InvalidOperationException($"Unsupported scheme: {uri.Scheme}");
    }
}
catch (UriFormatException)
{
    _type = DatabaseType.File;
}

Sending an absolute path like /home/user/database.sqlite will happily create a valid URI like file:///home/user/database.sqlite.

Please do not rely that URI is malformed for local files and provide a reliable way to open files from local disk.

Workaround is to pass a file with relative path like ../../database.sqlite which makes the new Uri() throw exception which will be catched and _type correctly set to DatabaseType.File.

[tvandinther]

Thank you for reporting this. Would adding a case for the file scheme be a sufficient resolution for you? I also think it would be worth adding the URL parsing to the test suite to avoid this bug in the future.

[jiri-matejka]

I missed that local files path is specified as file:/path/to/file in libSQL. Which actually works in your library, albeit it would maybe deserve a special handling in the code.

I found hard to understand that the options class has property Url where I am not actually passing a real URL. But it seems it is just a way how libSQL has it.

In case you would provide with an example with filename in your README.md and/or a documentation comment in the options class, I am fine with that :)

[tvandinther]

To ensure clarity I agree it would be a good idea to add a special case for handling the file: prefix explicitly for the connection URL rather than fully relying on the default fallback of using the filesystem. Added documentation on how to open different databases will also be a good addition.

Action points:

• Add explicit case for connection URLs prefixed with file: (Go docs example)
• Update documentation to show how to open various database locations