feat: don't read full file if range header is present

[JonnyBurger]

This PR contains a:

• bugfix
• new feature
• code refactor
• test update
• typo fix
• metadata update

Motivation / Use-Case

I am reading in a 2GB file for Remotion. This is a framework for making videos in React, and the end product is not shipped to a website, but written to an MP4 file. Therefore it's not a problem that we import these large files in Webpack.

However, when the browser is loading a video, and we seek forward, then a range header is sent to Webpack Dev Server. Unfortunately it is slow, because WDS is still loading the full file. I adapted the logic from serve-handler instead so instead of reading the full 2GB file synchronously, it uses a Read Stream.

Breaking Changes

No breaking changes.

[alexander-akait]

What we need to finish?

[codecov]

Codecov Report

Merging #1002 (75cbea1) into master (d80773b) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #1002   +/-   ##
=======================================
  Coverage   97.90%   97.91%           
=======================================
  Files          10       10           
  Lines         287      288    +1     
  Branches      100      102    +2     
=======================================
+ Hits          281      282    +1     
  Misses          6        6           

Impacted Files	Coverage Δ
src/middleware.js	96.15% <100.00%> (+0.15%)	⬆️
src/utils/handleRangeHeaders.js	100.00% <100.00%> (ø)

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[JonnyBurger]

@alexander-akait Sorry I forgot to remove the WIP notice. The PR is ready to be reviewed with no further changes intended on my side.

[alexander-akait]

I adapted the logic from serve-handler instead so instead of reading the full 2GB file synchronously, it uses a Read Stream.

Can you provide link on the original code?

[JonnyBurger]

Can you provide link on the original code?

It's here:
https://github.com/vercel/serve-handler/blob/c7a40435bc28b420a725e6dc1e9565d5b845dee2/src/index.js#L707-L733

[JonnyBurger]

Is there anything left I can do to help this PR progress?

[alexander-akait]

@JonnyBurger Sorry for delay, still in my TODO, hope I will merge it on this week

[JonnyBurger]

No stress!