fileSize limit on fastify-multipart did not throw error

I don’t know if I use it correctly or not but it is just pass through if I passing file with size higher than limit.

/*
 * other code
 */

fastify.post('/upload', async function (req, reply) {
    const data = await req.file({
      limits: {
        fileSize: 1 * 1024 * 1024,  // 1mb limit
      }
    })

    await pump(data.file, fs.createWriteStream(data.filename))

    reply.send()
})

It write file to my directory, when I expect it to throw error

• node version: 14.15.3
• fastify version: 3.9.2
• fastify multipart version: 3.3.1
• os: WSL

[mcollina]

Yes, busboy marks a file with truncated when the file limit was reached. In my opinion, an error should be thrown but I can’t remember why we didn’t implement it. According to busboy the library will only emit a limit event on the file object.

I guess we should error this.

[StarpTech]

I think the current behavior is correct because we can only guarantee error handling for a stream when we iterate over all parts until onEnd is called. In all other cases, the user can check for file.truncated after the stream was consumed. The req.file API is error-prone because it can’t report the final error.

hi all, I just try the new version 4.0.0 but unfortunately the problem still exist when using req.file, req.files and req.parts but works when using req.saveRequestFiles.

I couldn’t reproduce it. It is only valid for req.file. Please provide a reproducible example.