Reading an empty file results in a confusing "Input file contains unsupported image format" error

[scriptin]

Possible bug

Is this a possible bug in a feature of sharp, unrelated to installation?

• Running npm install sharp completes without error.
• Running node -e "require('sharp')" completes without error.

If you cannot confirm both of these, please open an installation issue instead.

Are you using the latest version of sharp?

• I am using the latest version of sharp as reported by npm view sharp dist-tags.latest.

If you cannot confirm this, please upgrade to the latest version and try again before opening an issue.

If you are using another package which depends on a version of sharp that is not the latest, please open an issue against that package instead.

What is the output of running npx envinfo --binaries --system --npmPackages=sharp --npmGlobalPackages=sharp?

  System:
    OS: macOS 14.4.1
    CPU: (10) arm64 Apple M1 Max
    Memory: 117.39 MB / 18.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.6.0 - ~/.local/state/fnm_multishells/85165_1734955094405/bin/node
    npm: 10.8.2 - ~/.local/state/fnm_multishells/85165_1734955094405/bin/npm
  npmPackages:
    sharp: ^0.33.5 => 0.33.5

Does this problem relate to file caching?

The default behaviour of libvips is to cache input files, which can lead to EBUSY or EPERM errors on Windows.
Use sharp.cache(false) to switch this feature off.

• Adding sharp.cache(false) does not fix this problem.

Does this problem relate to images appearing to have been rotated by 90 degrees?

Images that contain EXIF Orientation metadata are not auto-oriented. By default, EXIF metadata is removed.

• To auto-orient pixel values use the parameter-less rotate() operation.

• To retain EXIF Orientation use keepExif().

• Using rotate() or keepExif() does not fix this problem.

What are the steps to reproduce?

1. Create an empty image file touch test.jpg
2. Try reading it, e.g. by doing sharp('test.jpg').toBuffer();

File extension doesn't matter, I've tried *.avif, *.png, etc.

Result:

> node index.js
/Users/dmitry/Projects/sharp-empty-image/node_modules/sharp/lib/output.js:163
  const stack = Error();
                ^

Error: Input file contains unsupported image format
    at Sharp.toBuffer (/Users/dmitry/Projects/sharp-empty-image/node_modules/sharp/lib/output.js:163:17)
    at Object.<anonymous> (/Users/dmitry/Projects/sharp-empty-image/index.js:3:19)
    at Module._compile (node:internal/modules/cjs/loader:1546:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1691:10)
    at Module.load (node:internal/modules/cjs/loader:1317:32)
    at Module._load (node:internal/modules/cjs/loader:1127:12)
    at TracingChannel.traceSync (node:diagnostics_channel:315:14)
    at wrapModuleLoad (node:internal/modules/cjs/loader:217:24)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:166:5)
    at node:internal/main/run_main_module:30:49

What is the expected behaviour?

Some kind of error which explicitly tells that the file is empty.

Please provide a minimal, standalone code sample, without other dependencies, that demonstrates this problem

const sharp = require('sharp');

// test.jpg must exists and be empty
sharp('test.jpg').toBuffer();

Please provide sample image(s) that help explain this problem

[lovell]

This is something that would need to be addressed in the upstream libvips dependency as it currently does not differentiate between empty and non-empty files.

$ touch empty.jpg
$ echo "fail" >not-empty.jpg
$ vipsheader empty.jpg 
vipsheader: VipsForeignLoad: "empty.jpg" is not a known file format
$ vipsheader not-empty.jpg 
vipsheader: VipsForeignLoad: "not-empty.jpg" is not a known file format