Detect use of UI5 release that is out of maintenance or scheduled for CDN removal

[boghyon]

In addition to my previous requests:

• Detect UI5 "Default Version" Bootstrap #789
• Promote "Renovate" docs#108

Even if a project specifies a UI5 version somewhere in an attempt to avoid the "Default Version", at some point, the UI5 release of the specified version will be outdated and, in case of CDN, eventually removed from the cloud entirely.

If a project uses an outdated UI5 version e.g. via ...

• CDN
• UI5 CLI
• destinations (e.g. in neo-app.json, app router, etc.)
• SAP Fiori tools
• manifest section /sap.platform.cf/ui5VersionNumber

... UI5 linter detecting it would improve the chance to alert the owner of the project early in this regard.

In the report:

• Error if CDN is detected, as the outdated version will be removed soon. Warning otherwise.
• Possible solutions: similar to those from #789.

[flovogt]

JIRA: CPOUI5FOUNDATION-1050

[boghyon]

Out of UI5 linter scope but while we're at it:

@margopolo @KlattG @flovogt @jdichev
I'd even vote for displaying a message strip in the UI at runtime; in Demo Kit as well as all apps if affected.
And in case of CDN: a fat warning dialog

[codeworrior]

I'd even vote for displaying a message strip in the UI at runtime; in Demo Kit as well as all apps if affected.
And in case of CDN: a fat warning dialog

This was discussed when "end-of-cloud-provisioning" and Evergreen were introduced. At least in UI5 1.x there was no fully compatible way to inject this into an otherwise unknown HTML page (app). We can discuss this for 2.x again, constraints there are a bit different as bootstrap will always be async.

The other counter argument at that time was that the message reaches end users but should better reach admins / developers. We have no mean to distinguish those scenarios, however.

Adding @petermuessig as he was the driver of the discussion at that time.

[boghyon]

The other counter argument at that time was that the message reaches end users but should better reach admins / developers. We have no mean to distinguish those scenarios, however.

While this is still the case, informing end users would be still better than having them suddenly face a blank page at some point. Either way, they would end up contacting admins / devs / support, but with less urgency in case of a warning message (compared to a blank page).

I can't think of any other way to inform all organizations that still rely on outdated versions from the CDN.

It may be worth revisiting this topic already today for scenarios where the bootstrap is always async (e.g. -legacy-free URLs with a specific version).