Error Unexpected token (Object spread) when running jest with --coverage OR transform key

Not entirely sure if this is an issue with jest or ts-jest, but ts-jest seemed more likely so opening the issue here.

Issue

When I run jest with coverage turned on jest --coverage and the tranform key present in package.json e.g.:

"transform": {
      "^.+\\.tsx?$": "ts-jest"
    },

every test that involves an object spread operator fails.

If I either:

• run jest without --coverage or
• run jest without the transform key present in package.json

all tests pass fine (in the second case, minus of course typescript tests, which I need ts-jest’s transform for 😬 )

I’m running: ts-jest: 21.2.4 jest: 21.2.1 node: v8.9.0 npm: 5.6.0

I am not using any kind of babel config, although while investigating this problem I tried using babel-plugin-transform-object-rest-spread, but it didn’t seem to have made a difference.

Minimal Repo

Link to a minimal repo that reproduces this issue. There’s also a branch that shows what happens when transform is removed from package.json Travis is configured on this repo. Relevant build

Additional background info

Before using ts-jest, I had this problem with core jest as well, but then a new release of jest fixed the problem and everything worked as expected. The PR that fixed it was this one: https://github.com/facebook/jest/pull/4519

Any thoughts on what the problem might be? 🙇

[kulshekhar]

@wilhelmklopp I haven’t looked at this yet but I’m hoping to find some time after work today.

[kulshekhar]

it could be, and this is just conjecture, because jest processes everything using babel whereas instanbul doesn’t.