Implement upgrade_only_if_version_changes in manifest

[Josue-T]

The problem

• Fix ynh_check_app_version_changed behavior #756 (comment)
• There are actually not a simple way to detect if we need to do in action in the upgrade script only for some specific old package version. Actually we try to find somewhere a difference and test this difference.

Solution

Implement in the core this concept

Add helper ynh_compare_package_version.

PR Status

Work done

How to test

• Install an app.
• Add "upgrade_only_if_version_changes":true in the manifest
• Upgrade an app in debug mode and see that you will have environment variable named YNH_APP_UPGRADE_TYPE which will give you the type of upgrade. It could be:
  • UPGRADE_FORCED when there are nothing to update but the user forced the update
  • UNKNOWN for the app which don't use the correct syntax for the app version management.
  • UPGRADE_FULL when the upstream and the package need an update.
  • UPGRADE_APP when the upstream need to be updated.
  • UPGRADE_PACKAGE when the package need to be updated.
• You will see that no upgrade will be done if there are nothing to update but you still can fore this with -F.
• Try the helper ynh_compare_package_version in the upgrade of an app.

Validation

• Principle agreement 0/2 :
• Quick review 0/1 :
• Simple test 0/1 :
• Deep review 0/1 :

[maniackcrudelis]

And globally, add fucking comments !!!
We shouldn't have to try to figure out how it works !

[alexAubin]

Apart from remaining small comments to improve code, that looks good to me ! Thanks for bearing with the question / suggestions 😅

[alexAubin]

LGTM

[SilverViper]

Fixes #33 ?

Edit: link because markdown on mobile is flawed:
YunoHost/issues#33

[alexAubin]

c.f. a quick discussion on the chat : I'm proposing to enable this behavior by default, without adding/enabling the option in every manifest app (which is going to be a pain in the ass because we have 140+ apps and hmpf)

To be discussed during tomorrow's meeting

[zamentur]

I suggest a break change:

-f is used in install operation as in other part of the cli. I suggest to define -F for --file and -f for --force.

This change concerns packagers, and i prefer a break change for packager, than an inconsistency for final users

[alexAubin]

N.B. : it's used here : https://github.com/YunoHost/package_check/blob/master/sub_scripts/testing_process.sh#L965 so gotta be careful

I'm okay with the change but maybe we can do this in a separate PR to move forward ...