[Bug] Cannot read property stream of null

[Mitchnsun]

Current behavior:

I tried to test the upload of a CSV file. Front side, I use CSV-file-validator to read and validate my file. But I have a parsing error (see below, cannot read stream of null) that I do not have outside of cypress. During cypress test, I can console.log file (see code below) and cannot see a difference between in cypress or in a real browser...

I am not sure the issue is from cypress-file-upload library, but I only have this issue during testing with cypress (I create an issue on the repo of csv-file-validator).

Desired behavior:

CSV-file-validator could parse the file.

Steps to reproduce: (app code and test code)

Cypress: cy.get('input[type=file]').attachFile('myfile.csv'); Front:

function onFileUploaded(event) {
    const file = event.target.files[0];
    CSVFileValidator(file, CSVConfig)
      .then(csvData => {
          /* Do stuff with csvData */
      })
      .catch(err => console.error(err) });
  };
}
<input type="file" accept=".csv" onChange={onFileUploaded} />

Trace error:

TypeError: Cannot read property 'stream' of null
    at Object.parse (papaparse.min.js:46)
    at csv-file-validator.js:17
    at new Promise (<anonymous>)
    at csv-file-validator.js:16
    at Cr (AccountantFileUpload.js:64)
    at Object.<anonymous> (react-dom.production.min.js:49)
    at d (react-dom.production.min.js:69)
    at react-dom.production.min.js:73
    at k (react-dom.production.min.js:140)
    at T (react-dom.production.min.js:169)

Versions

Yarn: 1.12.3 Cypress: 4.3.0 Cypress-file-upload: 4.0.4 Csv-file-validator: 1.8.0 React: 16.6.0 MacOS: 10.14.6

[Mitchnsun]

I may find something, in PapaParse they have this condition: if ((global.File && _input instanceof File) || _input instanceof Object) (l.246) _input is my file in this case.

But in cypress my file is not an instance of File nor Object, that's why it cannot parse it. It seems that cypress-file-upload generate a file with a type object not Object or File It is weird, this is what I got:

Object.create(file) instanceof Object -> false
Object.create({}) instanceof Object -> true

[Mitchnsun]

I create a repo to reproduce easily the issue: https://github.com/Mitchnsun/bug-cypress-csv-upload

I am not sure if the issue comes from cypress-file-upload or from Cypress and how they create a Blob/File.

[abramenal]

Hi, thanks for submitting the issue!

Right now I am not able to take a look into the issue properly. In the meantime, I can suggest to check if the issue exist in v3 (previous major version): https://github.com/abramenal/cypress-file-upload/tree/v3.5.3 Sorry about that. Not sure I can provide ETA on solving this issue in v4 since I am the only one contributor and maintainer. If you have ideas on fixing that, please feel free to open Pull Request and we can review it together.

Thanks for understanding.

[jdcl32]

this is the same issue as https://github.com/abramenal/cypress-file-upload/issues/174, that can be fixed by: https://github.com/abramenal/cypress-file-upload/pull/184

[Mitchnsun]

Thanks @abramenal for your answer, I tried with the v3.5.2 and the issue doesn't exist on this version. Thanks @jdcl32 for the PR

I will work with the 3.5.2 until the @jdcl32 's PR will be merged

[abramenal]

Hi @Mitchnsun can you please check that again in v4.0.5?

[Mitchnsun]

It works fine now with the v4.0.5 ! Thank you

[scorp-dmitriy]

For everyone who came here looking for solution, here's a workaround from https://github.com/cypress-io/cypress/issues/933#issuecomment-345554793

// nope
// this is using the global window in the test spec
new File() 

cy.window().then((win) => {
  // yup
  // this is using the File constructor from the application window
  new win.File()
})

[tnrich]

I'm seeing this issue in Cypress v7.1.0

Still not sure how to fix it.. I can't change the internals of how papaparse work. Has anyone got this working with papaparse specifically?

Thanks!