Feature Request: Cascading settings (with a hardcoded default.json?)

[DHowett-MSFT]

Proposal

Include a default profiles.json in the package, allow the user to override it and merge their settings into it.

Questions

• What if you want to delete a stock profile?
• Optional features?
• Turn off defaults? Perhaps {... "thing": null, }?

Child Work Items

• ignore json profile data not understood #1880 Keep the original json blob around, and when we make edits to it, only append them or replace the existing values

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Things that need to be done to accomplish Cascading Settings

Each <h3> here is a single PR into master, broken into either sub-PRs or work for me to do as a part of that PR

[x] Don't re-serialize settings on load (PR: #2475)

This should be done first and foremost. This is not really helping anyone. Old settings all migrate nicely, so whatever. Let's just pull it.

[_] Combine a defaults.json with a profiles.json (PR: #2515)

• Add a defaults.json to the package
• Create a function for layering a Json::Value on top of an existing object
• Add tests for layering a profile json blob on top of a profile
• Add functions to search a list of Profiles for a duplicate, and layer on that dupe or create a new Profile if no such dupe exists.
• Ensure we can layer each of the following: (WITH TESTS)
  • layer profiles
  • layer color schemes
  • layer keybindings (for a matching key, the user action should override the default action) (NEEDS TESTS)
  • layer globals (NEEDS TESTS)
• When loading settings, load defaults, then layer user settings on top of default profiles
• Maintain user settings ordering, not defaults+user ordering
• Add support for unbinding default keys
  • unbind with "unbound"
  • unbind with null
• Add support for hiding profiles
• Ensure that we can reset optional default settings with null (e.g. "iconPath": null)
• Create the User Settings file if it doesn't exist
• Stamp the "defaults.json" file into the code, so we can't possibly fail loading it
• Add support for Alt clicking on "settings" to launch the defaults.json file
• default construct profiles with scheme "Campbell" to make "scheme" and unnecessary setting in the partial diff

[_] Add Dynamic Profile Generators

• Add Dynamic Profile Generator for WSL
  • Create Dynamic Profile Generator interface
  • Provide DPG's with GetNamespaceGuid and GetGuidForName functions from App somehow We're not doing this anymore. We'll create the GUID for the profile when it's returned, if it has a GUID of {0}
    • Add a test for generateing a guid based on namespace if GUID is {0}
  • Add layering for dynamic profiles based on guid and source, not just guid
• Add Dynamic Profile Generator for Powershell Core
• Add Dynamic Profile Generator for Azure Cloud Shell
• Ensure that existing WSL, Powershell Core, and Azure profiles gracefully migrate to dynamic profiles
• Add disabledProfileSources in user settings to hide dynamic profiles by namespace
• On first launch of the terminal, if Powershell Core exists, make it the default profile
• When adding this profiles, insert them into our JSON parse tree to save them
  • Only add the delta between the default profile and the dynamic profile's default state to the json. Don't include any user customizations (though at this point there won't be any)
• Ensure adding a dynamic entry doesn't reformat settings
• For profiles that were created from a dynamic profile source, they'll have both a guid and source guid that must both match. If a user profile with a source set does not find a matching profile at load time, the profile should be ignored.
• profile diffs should probably not include "table". Probably don't need to include in the diff keys that are std::nullopt in both the base and derived.
• Make sure to re-order profiles so they're { user profiles, dynamics not in user profiles, defaults not in user profiles }

[_] Smart Serializing

This would be needed for a Settings UI, so we don't necessarily need it for 1.0

• Keep the original JSON parse tree around in memory
• Only serialize things different from defaults
  • profiles
  • schemes
  • keybindings

[DHowett-MSFT]

This will be helped by UUIDv5 profile GUIDs. I'll file that later.

[rbeesley]

The default profiles.json should also be recreated from the application itself if the user makes a breaking change. They could uninstall and then reinstall, but that has a lot of negative problems as well such as losing any customizations they might have already made. It'd be better to give a path for recovery if the user makes a mistake and there is a chance this could happen if the user is given the chance to modify on their own.