image-size

Postconditions — what we check

• imageSize · unsupported-format

  error
  WhenImage format is unsupported or buffer is not a recognized image format
  ThrowsTypeError ('unsupported file type: ...' or 'disabled file type: ...')
  Required handlingCaller MUST wrap imageSize() in try-catch as it throws synchronously on unrecognized formats.
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[1]
• imageSize · corrupt-image

  error
  WhenBuffer contains corrupt or truncated image data
  ThrowsTypeError ('Corrupt JPG', 'Invalid PNG', etc.)
  Required handlingCaller MUST wrap imageSize() in try-catch as it throws on corrupt image data.
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[1]
• imageSizeFromFile · file-not-found

  error
  WhenFile path does not exist or cannot be read
  ThrowsError (ENOENT, EACCES)
  Required handlingCaller MUST wrap imageSizeFromFile() in try-catch as it rejects on file system errors.
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[2]
• imageSizeFromFile · unsupported-format

  error
  WhenFile is not a recognized image format
  ThrowsTypeError ('unsupported file type: ...')
  Required handlingCaller MUST wrap imageSizeFromFile() in try-catch as it rejects on unrecognized image formats.
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[1]
• imageSizeFromFile · empty-file

  error
  WhenFile exists at the given path but has zero bytes (size <= 0)
  ThrowsError ('Empty file')
  Required handlingCaller MUST wrap imageSizeFromFile() in try-catch. An empty file rejects with Error('Empty file'), which is distinct from ENOENT (file missing) and from TypeError (unsupported format). Upload pipelines that check file existence before dimensions must also guard against the file being zero-length.
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[2][3]
• imageSizeFromFile · corrupt-image-async

  error
  WhenFile exists and is readable but contains corrupt or malformed image data
  ThrowsTypeError (e.g. 'Corrupt JPG, exceeded buffer limits', 'Invalid PNG', 'Invalid WebP', etc.)
  Required handlingCaller MUST wrap imageSizeFromFile() in try-catch. When the file contains corrupt image data, the async wrapper rejects with the same TypeError thrown by the synchronous imageSize() parser. Callers checking only for ENOENT/EACCES will miss format corruption errors from user-uploaded files.
  costlowin prodimmediate exceptionusers seeservice unavailablevisibilityvisible
  Sources[2][1]

Sources

Every postcondition cites at least one of these. Numbered to match the footnotes above.

1. [1]github.com/image-size/image-sizehttps://github.com/image-size/image-size/blob/main/lib/index.ts
2. [2]github.com/image-size/image-sizehttps://github.com/image-size/image-size/blob/main/lib/fromFile.ts
3. [3]github.com/image-size/image-sizehttps://github.com/image-size/image-size/issues?q=empty+file