Non-null assertion operator syntax highlighting error in class based SF-component

[d-n-x]

• I have searched through existing issues
• I have read through docs
• I have read FAQ

Info

• Platform: Windows 10
• Vetur version: 0.11.7
• VS Code version: 1.20.1

Problem

It seems like that the non-null assertion operator inside vue component works correctly within the TypeScript compiler but the syntax highlighting seems to be wrong.

https://i.imgur.com/7luF67C.jpg

Reproducible Case

Create a class in a single-file component and add a variable with the non-null assertion operator:

export default class Test extends Vue {
  @Prop() msg!: string; // '=' expected.
  @Prop() test?: number; // Working.
}

[HerringtonDarkholme]

We will make a new release for this. Please wait patiently. #686