fix: add $forChildren parameter to IPartialMountProvider

[salmart-dev]

Summary

Adds a $forChildren parameter to IPartialMountProvider so that providers have clear information about when they should load a single mount or all mounts in a path.

TODO

• ...

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

[icewind1991]

Would it make sense to have $forChildren return both the mounts for $path and for the children, instead of only the children.

Otherwise, if a folder and it's child-mounts have the same mount provider, we would be calling the provider twice.

Though it might be more work for the provider to deal with the "both" case instead of only for the children.

[salmart-dev]

Would it make sense to have $forChildren return both the mounts for $path and for the children, instead of only the children.

Otherwise, if a folder and it's child-mounts have the same mount provider, we would be calling the provider twice.

Though it might be more work for the provider to deal with the "both" case instead of only for the children.

The current flow of setupForPath is to get the mount for the given path and then for the children if $includeChildren is true. This was not a problem before because we were tracking which providers were already set up and skip them when necessary. Now, if we'd have the call for the children also return the mount for $path we'd have to manually remove it which would be cumbersome + cause ugly outcomes in those providers that have side-effects when building mounts (e.g. SharedMount).

Regarding the issue of calling the provider multiple times, I am trying to take extra care so that if it happens, we don't end up setting up the same mounts more than once.

If the setup is called for a folder with $forChildren set to true, any setup call for sub-paths will be a no-op.

[icewind1991]

Would it make sense to have $forChildren return both the mounts for $path and for the children, instead of only the children.
Otherwise, if a folder and it's child-mounts have the same mount provider, we would be calling the provider twice.
Though it might be more work for the provider to deal with the "both" case instead of only for the children.

The current flow of setupForPath is to get the mount for the given path and then for the children if $includeChildren is true. This was not a problem before because we were tracking which providers were already set up and skip them when necessary. Now, if we'd have the call for the children also return the mount for $path we'd have to manually remove it which would be cumbersome + cause ugly outcomes in those providers that have side-effects when building mounts (e.g. SharedMount).

Regarding the issue of calling the provider multiple times, I am trying to take extra care so that if it happens, we don't end up setting up the same mounts more than once.

If the setup is called for a folder with $forChildren set to true, any setup call for sub-paths will be a no-op.

Fair enough, we can always tweak things in the future.