fix(upload): accept File or File[] #529

[ph-fritsche]

What:

const f = new File(/*...*/)

// these two will be equivalent
userEvent.upload(element, [f])
userEvent.upload(element, f)

Why:

Previous implementation required the user to provide File for single file inputs and File[] for multiple file inputs.

How:

Convert to an array if it is not.
Truncate to length 1 if input is not multiple.

Checklist:

• Documentation
• Tests
• Typings N/A
• Ready to be merged

[codecov]

Codecov Report

Merging #530 (f645798) into master (6c21e1f) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #530   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           13        13           
  Lines          675       675           
  Branches       211       213    +2     
=========================================
  Hits           675       675           

Impacted Files	Coverage Δ
src/upload.js	100.00% <100.00%> (ø)

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[kentcdodds]

I'm not sure I understand the motivation for this change.

Previous implementation required the user to provide File for single file inputs and File[] for multiple file inputs.

I think that's sensible and expected. I'm what situation would I want to pass an array for a single or a single file for a multiple?

[ph-fritsche]

I think that's sensible and expected. I'm what situation would I want to pass an array for a single or a single file for a multiple?

As #529 demonstrated people get confused why their file input won't accept the file upload.

And I like the thought of being as agnostic as possible about implementation details.
If someone has a file input that changes to multiple a test where someone tries to upload a file to it should not fail.
If a file input changes away from multiple a test trying to e.g. drag&drop one file should still pass and one where he drags two files should fail because the second file gets lost not because of syntactic errors.

[kentcdodds]

That makes sense. Thanks!

[github-actions]

🎉 This PR is included in version 12.6.2 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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