Expose gopatch API as patch package

[vvakame]

closes #94
Expose gopatch API with minimal API.

[CLAassistant]

All committers have signed the CLA.

[abhinav]

This looks good to me from what I remember of the original code.

CC @sywhang @lverma14 @r-hang

[codecov]

Codecov Report

Attention: Patch coverage is 73.75000% with 21 lines in your changes missing coverage. Please review.

Project coverage is 87.41%. Comparing base (2ae6b02) to head (2392705).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
patch/gopatch.go	73.75%	14 Missing and 7 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #181      +/-   ##
==========================================
+ Coverage   87.30%   87.41%   +0.11%     
==========================================
  Files          39       40       +1     
  Lines        2457     3267     +810     
==========================================
+ Hits         2145     2856     +711     
- Misses        251      343      +92     
- Partials       61       68       +7     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[vvakame]

It seems that the normal code is all covered by the tests.
Do I need to add tests for errors to meet the coverage criteria?

[abhinav]

I think the missing error lines are fine as-is. You may want to rename patch.PatchFile to just patch.File.
Other than that, we'll need someone at Uber to merge this when they're ready.

[sywhang]

Thanks for the PR! I will take a look at this some time later tonight.

[vvakame]

thanks! I updated that abhinav's suggestion.

[vvakame]

@sywhang PTAL 🙏

(It's Monday evening in my time zone, but it might have been Sunday night there. Sorry!)