CherryHQ/cherry-studio · error · Error

Invalid MCP package upload: file name cannot be empty

Error message

Invalid MCP package upload: file name cannot be empty

What it means

Thrown by validatePackageUploadPayload when fileName.trim() is the empty string. The filename is checked after the typeof guard, so this means a real string consisting only of whitespace (or the empty string) was supplied. An empty filename cannot be used to build a safe temp-file path and indicates the upload payload was malformed.

Source

Thrown at src/main/ai/mcp/McpPackageService.ts:288

    resolvedEnv[key] = substituted
  }

  return resolvedEnv
}

export function validatePackageUploadPayload(
  fileBuffer: ArrayBuffer | NodeJS.ArrayBufferView,
  fileName: string,
  packageFormat: McpPackageFormat
): Buffer {
  if (typeof fileName !== 'string') {
    throw new Error('Invalid MCP package upload: file name must be a string')
  }

  const trimmedFileName = fileName.trim()
  if (!trimmedFileName) {
    throw new Error('Invalid MCP package upload: file name cannot be empty')
  }
  if (trimmedFileName !== fileName) {
    throw new Error('Invalid MCP package upload: file name cannot contain leading or trailing whitespace')
  }
  if (trimmedFileName.includes('\0') || /[/\\]/.test(trimmedFileName)) {
    throw new Error('Invalid MCP package upload: file name cannot contain path separators')
  }
  if (!/^[A-Za-z0-9._ ()@+-]+$/.test(trimmedFileName)) {
    throw new Error('Invalid MCP package upload: file name contains unsupported characters')
  }
  if (path.extname(trimmedFileName).toLowerCase() !== `.${packageFormat}`) {
    throw new Error(`Invalid MCP package upload: expected a .${packageFormat} file`)
  }

  let buffer: Buffer
  if (fileBuffer instanceof ArrayBuffer) {
    buffer = Buffer.from(fileBuffer)
  } else if (ArrayBuffer.isView(fileBuffer)) {

View on GitHub (pinned to 726446b54c)

Solutions

  1. Gate the upload button in the renderer on a non-empty file selection; only call the IPC when a File with a real .name is present.
  2. If the filename is constructed from user input, validate it is non-empty after trim before sending.
  3. Add a unit test that asserts the renderer never dispatches the upload IPC with an empty filename.

Example fix

// renderer - before
if (file) await upload(file.buffer, fileName.trim())
// after
if (file && file.name && file.name.trim()) await upload(await file.arrayBuffer(), file.name)
Defensive patterns

Strategy: validation

Validate before calling

function isNonEmptyFileName(fileName: string): boolean {
  return typeof fileName === 'string' && fileName.trim().length > 0
}

Type guard

function isNonEmptyTrimmedString(s: unknown): s is string {
  return typeof s === 'string' && s.trim().length > 0
}

Prevention

When it happens

Trigger: The renderer IPC call sent fileName = "", " ", or a value derived from a missing File.name. A form that let the user proceed without selecting a file, or a synthetic upload in tests, would produce this.

Common situations: UI form submitted with no file chosen but the upload handler ran anyway; the filename was extracted from a path with a malformed split; a File object whose .name is empty (rare, but possible for programmatic Blobs).

Related errors

AI-assisted analysis of CherryHQ/cherry-studio@726446b54c (2026-08-12). Data as JSON: /api/errors/6b20cd8d592945cc. Report an issue: GitHub.