@vue/cli-plugin-unit-mocha env var causes errors with vue-loader

[eddyerburgh]

Version

3.0.1

Reproduction link

https://github.com/girder/girder_web_components/blob/vue-test-utils-bug/tests/unit/HelloWorld.spec.js

Steps to reproduce

yarn install && yarn test:unit

What is expected?

Component should not error when mounted

What is actually happening?

Error is thrown (TypeError: Cannot read property 'parent' of undefined)

---

The issue is when a component has a prop of parent, component is built with vue-loader when target equals node, and the component is mounted.

When the normalizeComponent function runs, it accesses this.parent. This throws an error, because the component _props has not yet been added, although the parent getter already has been added in initProps.

Removing target: node fixes this. What was the reason for including it in the config?