Auto-Update and New Version Notification for PowerShellGallery Modules imported/installed

Summary of the new feature / enhancement

Related to #495

Problem Statement

Module owners have difficulty getting users to upgrade to the latest stable version of their module. This means that users are often are on older and worse versions of modules, which has the potential to have security flaws, breaking bugs and issues.

Potential Solution

Have PowerShellGet somehow check for newer versions with the PowerShellGallery automatically and in the background. There are two approaches to encourage updating to the latest version

1. Notify the user with a prompt explaining there current module is not the latest release and they should update via Update-PSResource -Name <MODULE_NAME>

   • Potential notification There is a version of <MODULE_NAME> available from the PowerShellGallery, would you like to install it? [Y] Yes [N] No:

2. Allow the users to opt into automatic updates for specified modules

   • When installing specific module (parameter -EnableAutoUpdate for example)
   • Or later configuration

Proposed technical implementation details (optional)

Potential Example Scenarios

On terminal startup (module import)

When the user opens a new PowerShell terminal, a check of the imported modules for newer versions is ran to notify the users that ModuleA, ModuleB...etc has a newer version available on PowerShellGallery.

On cmdlet use

User uses a cmdlet from a specific PowerShell module, <ModuleA_Cmdlet>, after cmdlet is run, a check against that module is run and user is notified if there is a newer version available.

When installing module

When installing a module user has a -EnableAutoUpdate Parameter they can set with Install-PSResource to have PowerShellGet auto-update module on import.

Security Considerations

In the scenarios for auto-updating, there would have to be some form of package signing within PowerShell Gallery. If a previous version of a package was signed, then the next version should be signed with the same certificate. Additionally have a way to override this requirement to account

No files, tests, or entry points are named. Start by reading related issue #495 and tracing the existing Install-PSResource, Update-PSResource, and module-import flows; define the notification, opt-in update, background-check, and package-signing requirements before implementation.