fix(core): stable route sorting

[pimlie]

Types of changes

• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

This PR fixes route sorting in Node v11 (fix #4188).

The problem was caused because the route sorting in Nuxt was inherently unstable due to default ordering to be dictated by the order in which elements where compared. This caused issues in v11 because quicksort compares arr[0] with arr[1] but timsort does arr[0] with arr[arr.length - 1].
E.g. if you look at the dynamic-routes test then with quicksort it compared parent to test but in timsort it compared test to parent. As the default behaviour of route sorting was to return 1, this meant that if there was no 'special' case a was always sorted after b regardless of its actual value (hence the inherently unstable). This PR changes this behaviour to alphabetically sort a and b (with localeCompare) if there is no 'special' case.

I have also moved route sorting outside the forEach loop, there is no need to sort the routes array on every intermediate step and it probably saves a little bit of time to only sort it once.

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly. (PR: #)
• I have added tests to cover my changes (if not applicable, please state why)
• All new and existing tests are passing.

[clarkdo]

LGTM

[codecov-io]

Codecov Report

Merging #4331 into dev will increase coverage by 0.03%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##              dev    #4331      +/-   ##
==========================================
+ Coverage   91.05%   91.09%   +0.03%     
==========================================
  Files          56       56              
  Lines        1845     1852       +7     
  Branches      466      467       +1     
==========================================
+ Hits         1680     1687       +7     
  Misses        154      154              
  Partials       11       11

Impacted Files	Coverage Δ
packages/common/src/utils.js	98.63% <100%> (+0.05%)	⬆️
packages/webpack/src/config/base.js	95.31% <0%> (-0.08%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 3702dfe...47691ba. Read the comment docs.

[pimlie]

Azure fails (again, intermittently) on the components test. The route sorting should be stable now between v10 and v11. Maybe we can add v11 testing to CI before merging this to make sure it does?

[clarkdo]

I will trigger azure rebuild.
I think we can merge it asap and I’ll add v11 into CI shortly.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.