Improvements/fixes for reading state.json

[chrisbreiding]

In an attempt to mitigate Cypress randomly hanging in CI, implement the following:

1. Add debug logs around reading/writing/locking/unlocking files, so if the issue occurs again, they'll hopefully provide more information
2. Stop the state.json file from being read during run mode. The last log before Cypress hanging is the state.json being read, so it's possible it is the cause. Since we solely persist state related to the GUI/browser in interactive mode, it's not necessary to read it at all during a run. This may solve the issue.
3. Add a timeout for unlocking a file. If the hanging is indeed caused by the state.json, it's likely it's actually unlocking the file that never resolves. It would be better to time out in this scenario, catch the timeout, and carry on without the file unlocked. There's already a timeout on getting a lock on the file, so subsequent read and writes will handle that accordingly.
4. Add a whitelist for keys that can be saved in state.json. Currently, it allows any arbitrary keys to be written to it, making it difficult to tell what state it actually can possibly contain. This will document the keys in the code.

[bahmutov]

Excellent ideas and we can document the keys using json schemas to enforce them

…

Sent from my iPhone

On Jun 22, 2018, at 09:50, Chris Breiding ***@***.***> wrote: In an attempt to mitigate Cypress randomly hanging in CI, implement the following: Add debug logs around reading/writing/locking/unlocking files, so if the issue occurs again, they'll hopefully provide more information Stop the state.json file from being read during run mode. The last log before Cypress hanging is the state.json being read, so it's possible it is the cause. Since we solely persist state related to the GUI/browser in interactive mode, it's not necessary to read it at all during a run. This may solve the issue. Add a timeout for unlocking a file. If the hanging is indeed caused by the state.json, it's likely it's actually unlocking the file that never resolves. It would be better to time out in this scenario, catch the timeout, and carry on without the file unlocked. There's already a timeout on getting a lock on the file, so subsequent read and writes will handle that accordingly. Add a whitelist for keys that can be saved in state.json. Currently, it allows any arbitrary keys to be written to it, making it difficult to tell what state it actually can possibly contain. This will document the keys in the code. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or mute the thread.

[brian-mann]

Released in 3.0.2.