Version:

vue-loader@9.4.2

Repro:

https://github.com/HerringtonDarkholme/vue-loader-test/tree/constructor

npm install && ./node_modules/.bin/webpack && python3 -m http.server

Expected:

Exported constructor should work according to the doc.

Actual:

Vue complains Failed to mount component: template or render function not defined. (found in root instance)

Problem:
typeof __vue_modules__.default === 'object' breaks exported constructors.

Though exported constructor is not recommended, but it is the only way I can find to cooperate with class component library...