Vue 2 - Jest stack trace line numbers wrong with TypeScript and Babel for SFC components

[truuman]

Subject of the issue

When running unit tests for Vue 2 SFC components with jest via vue-test-utils (+babel +typescript) the reported stack trace error line numbers are wrong.

Steps to reproduce

1. Create a new Vue CLI project: npx @vue/cli create repro-project
   
2. Edit HelloWorld.vue component by adding a mounted() {} lifecycle hook containing something like this:

   mounted() {
     this.iAmNotDefined = iAmNotDefineder
   }

3. Run npm run test:unit

or pull my repro repo and run npm install && npm run test:unit

Expected behaviour

The correct line number is shown in the stack trace.

Actual behaviour

The opposite of the expected behaviour.

Possible Solution

My hunch says it's a transformation issue, but I've no idea if it's ts-jest, vue-jest, babel-js or the sfc compiler.

[lmiller1990]

Almost certainly a Vue Jest issue!