* We should try loading Angular.JS for the upgrade tests in their minfied output. There seems to be a lot flakiness in regards to loading `AngularJS` within Travis, and the `onerror` messages aren't really too helpful. In order to reduce the payload that will be passed through the Saucelabs tunnel, we should try to load the minfied output files.
PR Close#27711
Currently whenever the upgrade test helper fails to load a given AngularJS version, the error that will be rejected is technically not an error because the `onerror` callback is not returning an error, but an "ErrorEvent".
Since that `ErrorEvent` is basically just rejected, browsers will print
the error as followed:
```
Failed: [object Event]
```
This is not helpful at all and also implies that there _might_ be more
information hidden within the `Event` instance. Unfortunately that's not
the case (at least on browsers we test against) and the logic to extract
the data from the event would be not worth the effort, we just return a
simple custom `Error` that won't imply that there is more information
hidden.
PR Close#27706
Previously, only simple, single-slot transclusion worked on upgraded components.
This commit fixes/adds support for the following:
- Multi-slot transclusion.
- Using fallback content when no transclusion content is provided.
- Destroy unused scope (when using fallback content).
Fixes#13271
Paul Gschwendtner
Greg Magolan
George Kalpakas
Miško Hevery
Pete Bacon Darwin
Jason Aden