feat(core): support loading basedirs from config

[chawyehsu]

• BLOCKED BY refactor(config): Move config handling to core.ps1 #3242 (MERGED)

Reopen #3116 . This is a breaking change.

• revert source config.ps1 in scoop bin #3115 , import config.ps1 in core.ps1 instead
• add support loading env from ~/.config/scoop/config.json config file, preparing for the new scoop installer (see scoopinstaller/install#2 and scoopinstaller/install#4)
• drop $oldscoopdir = "$env:LOCALAPPDATA\scoop" support, I think nobody use old scoop dir now, it has been 3 years.

[chawyehsu]

please also add please-review label. Once this pull request is accepted, ScoopInstaller/Install#3 will also be accepted and merged. And the new installer will be ready to use for develop channel users.

[chawyehsu]

/cc @r15ch13 @Ash258 @rasa

[Ash258]

I am not against this change in overall, but i like that idea, when you can adress scoop location in other scripts / programs using $env:SCOOP(_HOME). I usually use it a lot and it's more convenient to guide user (for example) using cd $env:SCOOP rather than cd (scoop config rootPath).

Should be global path set in .scoop file too?? Each users will have to set it on user creation / .. to match other users. Global path as machine environment variable is more suitable I think.

[chawyehsu]

@Ash258 It's ok to keep $env:SCOOP for users to adress scoop location. I prefer to get it from scoop config rootPath and set it to $env:SCOOP in the scoop runtime for users, instead of saving it to and getting it from environment variable. Will consider to tweak the implementation.

[r15ch13]

Using $env: and config values is a good solution, but which one has priority over the other?
Keep in mind that this might break scoop-extras/checkver.ps1 and other bin scripts.

[chawyehsu]

@r15ch13

1. I think config values should have higher priority, and $env:SCOOP is an 'alias' to scoop config rootPath.(Just, don't write environment variable if you can, please..) An user can get scoop path from $env:SCOOP but can only change the path from scoop config (but hey, is it really someone will change the scoop path after installation?)

2. It's ok.

   f(!$env:SCOOP_HOME) { $env:SCOOP_HOME = resolve-path (split-path (split-path (scoop which scoop))) }

@Ash258

Global path as machine environment variable is more suitable I think.

Agree.

[chawyehsu]

Now the changes is non-invasive, just added support of loading env from ~/.scoop config file, to reflect the future standalone installer.

[chawyehsu]

Anyone else wants to give a review?

[niheaven]

Reviewed and tested without reinstallation of Scoop. Online installation failed.

Rebased with #3242, but get_config is defined after $scoopdir and is unreachable.

After changing sequence of $scoopdir and get_config, online installation work well. (test branch and online install script, please see additional commit there).

@h404bi

[chawyehsu]

@niheaven Thanks for respone and test, will rebase the codes after getting #3242 adopted.