Fix regression in 3.5.0 where a cy.visit that changes superdoma…

[flotwig]

• Fixes Since 3.5.0, a cy.visit that changes superdomain incorrectly clears cookies of other domains. #5756

User facing changelog

• Fixed a regression in 3.5.0 where a cy.visit that changes superdomain would incorrectly clear cookies of other domains.
• cy.visits that cause a superdomain change will now result in 2 requests to your origin server. This should not affect tests, as tests will still re-run on a superdomain change.

Additional details

• created a sandbox repo to test Chrome cookies scenarios using Puppeteer: https://github.com/flotwig/google-chrome-behavior-tests
  • we are handling simple single-Set-Cookie flows correctly
• failure with cookies without whitelist in a cy.visit when redirected to a HTTP URL can set cookies on lots of redirects, ending with different domain: with localhost baseUrl
  • seems to be missing all cookies from non-localhost (quux.bar.net)
  • passes under cy.request, passes under same domain, passes under cy.request+same domain
  • issue occurs when superdomain changes - if you cy.visit the baseurl right before this test, it passes! otherwise the cookies from the alternate domain are wiped!
• having trouble reproducing the issues users are mentioning with cookies in cy.request
  • could be caused by obsolete multi-Set-Cookie syntax
  • most likely Cypress incorrectly validates domain of cookies in 3.5.0 #5656

How has the user experience changed?

PR Tasks

• Have tests been added/updated?
• Has the original issue been tagged with a release in ZenHub?

[cypress-bot]

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User Experience

• The feature/bugfix is self-documenting from within the product.
• The change provides the end user with a way to fix their problem (no dead ends).

Functionality

• The code works and performs its intended function with the correct logic.
• Performance has been factored in (for example, the code cleans up after itself to not cause memory leaks).
• The code guards against edge cases and invalid input and has tests to cover it.

Maintainability

• The code is readable (too many nested 'if's are a bad sign).
• Names used for variables, methods, etc, clearly describe their function.
• The code is easy to understood and there are relevant comments explaining.
• New algorithms are documented in the code with link(s) to external docs (flowcharts, w3c, chrome, firefox).
• There are comments containing link(s) to the addressed issue (in tests and code).

Quality

• The change does not reimplement code.
• There's not a module from the ecosystem that should be used instead.
• There is no redundant or duplicate code.
• There are no irrelevant comments left in the code.
• Tests are testing the code’s intended functionality in the best way possible.

Internal

• The original issue has been tagged with a release in ZenHub.

[cypress]

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Test summary

3515 • 0 • 45 • 0

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Run details

Project	cypress
Status	Passed
Commit	8a468b4
Started	Nov 26, 2019 6:20 PM
Ended	Nov 26, 2019 6:24 PM
Duration	03:34 💡
OS	Linux Debian - 9.8
Browser	Multiple

View run in Cypress Dashboard ➡️

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[flotwig]

@brian-mann there isn't an open issue for this AFAIK, think we should merge this in anyways? it definitely fixes some issue... people might not even know they have this issue

[brian-mann]

@flotwig definitely needs a corresponding issue opened. The regression fix is easily describable and should be noted in the issue.

[flotwig]

@flotwig definitely needs a corresponding issue opened. The regression fix is easily describable and should be noted in the issue.

Created one: #5756

[brian-mann]

Removing the superdomain stitching may in fact fix other esoteric issues that are open - but they may be very hard to find...

The superdomain visit buffering is likely the cause of other difficult to understand/debug issues due to the state changes that happen. This could have manifested itself in situations where Cypress changes the superdomain - but then does not serve itself correctly (instead it would proxy to the real origin server). Another possible candidate would be seeing the "Cypress did not launch this browser" message about not being able to connect to the automation extension.

@flotwig and @jennifer-shehane might be worth peaking around / searching through issues to see if we can find others that fixing this will close.