feat: allow cypress.config.js to be a default config file

[elevatebart]

• Closes https://cypress-io.atlassian.net/browse/UNIFY-374

User facing changelog

Now one can use cypress.config.js as a default config file instead of cypress.json

Additional details

• When this file is present, no cypress.json will be created

• If both files (json and js) are present cypress should error

• Desktop gui was adapted as well like so

PR Tasks

• Have tests been added/updated?

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[cypress]

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Test summary

18532 • 0 • 214 • 7 • 0

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Run details

Project	cypress
Status	Passed
Commit	22cfcc9
Started	Sep 28, 2021 6:40 PM
Ended	Sep 28, 2021 6:51 PM
Duration	10:47 💡
OS	Linux Debian - 10.9
Browser	Multiple

View run in Cypress Dashboard ➡️

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[lmiller1990]

If I have both cypress.json and cypress.config.js, I am not seeing the expected error. Instead, I just get "stack trace".

[elevatebart]

I think I forgot to add the conflict error.
Thank you for checking.

[jennifer-shehane]

1. When using cypress.config.js and setting up a project, the projectId is not being written to the the cypress.config.js file, it's instead creating a new cypress.json file and writing the projectId into that file. This means if they directly go to run the record run command - they'll get an error about 2 config files. This critical path has to be fixed.

   The same bug occurs if you pass a custom --config-file, it creates a new cypress.json and adds the projectId there instead.

2. If this is a JS file, the preview should show as module.exports = { projectId: ...}

   

3. Is the nodeVersion being used to read in their cypress.config.js also? Does that need to be noted here?

   

4. The percy snapshots are not working, not showing the correct config file in the desktop-gui screenshots.

[jennifer-shehane]

When you go to copy to clipboard the projectId preview when it's a JS file, including the module.exports, it only copies the JSON portion. This experience is odd. I'd expect it to copy the text that it is showing me.

A couple minor text fixes.

[elevatebart]

@jennifer-shehane copy to clipboard has been fixed in 22cfcc9

[jennifer-shehane]

Confirmed the copy to clipboard is now working.