Fix: Use defaultName when it exists to correctly stub async components

[Evertvdw]

When mounting a component that has components defined with defineAsyncComponent the result of type.name is AsyncComponentWrapper. The defaultName contains the filename which should get precedence over the type.name to make stubbing work correctly.

[cexbrayat]

Looks reasonable.

@xanf is that OK with you, as you changed this recently?

[Evertvdw]

@cexbrayat I just ran yarn run lint in the project in my branch but that has 100+ warnings. Seemed to also be indicated here: https://github.com/vuejs/vue-test-utils-next/runs/4445921989?check_suite_focus=true. Is that something I need to fix because I did not change anything in those files :)

[cexbrayat]

@Evertvdw It looks like it fails in files you updated (tests/components/ScriptSetupWithChildren.vue). Run yarn lint:fix and you should be good to go. If you have other errors, make sure you have up-to-date dependencies, as it should not be the case?

[Evertvdw]

Probably some git glitch, I ran the lint:fix and git changes said 105 changed files, but when comparing there were no differences for 104 out of 105. Fixed the one error that was there though :)