litedb-org/LiteDB · error · ArgumentNullException

filename

Error message

filename

What it means

ArgumentNullException thrown by LiteStorage<TFileId>.Upload(TFileId id, string filename) when the filename argument is null, empty, or whitespace. This overload reads a file from disk via File.OpenRead, so a valid path is required. The check uses IsNullOrWhiteSpace.

Source

Thrown at LiteDB/Client/Storage/LiteStorage.cs:157

        /// <summary>
        /// Upload a file based on stream data
        /// </summary>
        public LiteFileInfo<TFileId> Upload(TFileId id, string filename, Stream stream, BsonDocument metadata = null)
        {
            using (var writer = this.OpenWrite(id, filename, metadata))
            {
                stream.CopyTo(writer);

                return writer.FileInfo;
            }
        }

        /// <summary>
        /// Upload a file based on file system data
        /// </summary>
        public LiteFileInfo<TFileId> Upload(TFileId id, string filename)
        {
            if (filename.IsNullOrWhiteSpace()) throw new ArgumentNullException(nameof(filename));

            using (var stream = File.OpenRead(filename))
            {
                return this.Upload(id, Path.GetFileName(filename), stream);
            }
        }

        /// <summary>
        /// Update metadata on a file. File must exist.
        /// </summary>
        public bool SetMetadata(TFileId id, BsonDocument metadata)
        {
            var file = this.FindById(id);

            if (file == null) return false;

            file.Metadata = metadata ?? new BsonDocument();

View on GitHub (pinned to f906a5f850)

Solutions

1. Validate the filename/path is non-empty and the file exists before calling Upload.
2. Use File.Exists check before the upload call.
3. Return a validation error to the caller if the path is missing.

Example fix

// before
storage.Upload(id, uploadedPath); // uploadedPath may be null
// after
if (string.IsNullOrWhiteSpace(uploadedPath) || !File.Exists(uploadedPath))
    throw new ArgumentException("Valid file path required.");
storage.Upload(id, uploadedPath);

if (string.IsNullOrWhiteSpace(filename) || !File.Exists(filename))
    throw new ArgumentException("A valid file path is required.", nameof(filename));
storage.Upload(id, filename);

static bool IsValidUploadPath(string f) =>
    !string.IsNullOrWhiteSpace(f) && File.Exists(f);

try
{
    storage.Upload(id, path);
}
catch (ArgumentNullException ex) when (ex.ParamName == "filename")
{
    // path was null/empty; prompt the user or use a default
    throw;
}

When it happens

Trigger: Calling storage.Upload(id, null), storage.Upload(id, ""), or storage.Upload(id, " "). Also when the filename comes from user input or a form upload that was not populated.

Common situations: Web API receiving a file path that the client omitted. A configuration or environment variable for the source path being unset. Path construction from nullable components.

Related errors

• stream
• filename
• id
• connectionString
• field

AI-assisted analysis of litedb-org/LiteDB@f906a5f850 (2026-08-13). Data as JSON: /api/errors/ee34cb78f3fc9e39. Report an issue: GitHub.