fix(vue-app): middleware not executing on double browser back navigation

[jsonpoindexter]

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

When a Nuxt app is in Universal mode it is possible that in some cases a component's middleware does not execute.
This can happen when a user first navigates to a project page (example: Page B), server.js executes and then before client.js executes the user navigates to another page in the project (example: Page A). In this scenario https://github.com/nuxt/nuxt.js/blob/dev/packages/vue-app/template/client.js#L810 will evaluate to TRUE and not execute the middleware(s) for page A.

Resolves: https://cmty.app/nuxt/nuxt.js/issues/c10049 / #6716

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)
  I could not find a way to programmatically reproduce this issue ie. changes routes after server.js has executed, but before client.js executes.
• All new and existing tests are passing.

[codecov-io]

Codecov Report

Merging #6775 into dev will decrease coverage by 0.07%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##              dev    #6775      +/-   ##
==========================================
- Coverage   64.82%   64.75%   -0.08%     
==========================================
  Files          78       78              
  Lines        2718     2721       +3     
  Branches      706      708       +2     
==========================================
  Hits         1762     1762              
- Misses        729      730       +1     
- Partials      227      229       +2

Flag	Coverage Δ
#e2e	100% <ø> (?)
#unit	64.75% <0%> (-0.08%)	⬇️

Impacted Files	Coverage Δ
packages/vue-renderer/src/renderers/ssr.js	0% <0%> (ø)	⬆️

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[atinux]

Actually this makes sense, even if I cannot reproduce it on my machine (might be too fast).

Can you reproduce this on your slower machine when running nuxt start?

[jsonpoindexter]

@atinux yes, I am able to reproduce this in production mode.

[pi0]

Thanks @jsonpoindexter