shallowMount will not stubs lazily registered components

[ktsn]

Version

1.0.0-beta.24

Reproduction link

https://github.com/ktsn/vue-test-utils-shallow-repro

Steps to reproduce

1. clone the reproduction
2. npm i
3. npm t

You will see the test case is failing.

What is expected?

The Child.vue component should be stubbed by shallowMount.

What is actually happening?

The Child.vue component is not stubbed and simply rendered as is.

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The pattern which written in reproduction is an approach to deal with circular reference between components. It is stated in Vue.js official documentation. So I think it would be useful if we can handle such pattern on shallowMount.