Unexpected token '-'. Expected ';' after variable declaration

[essekia]

beforeEach failed on setup: Unexpected token '-'. Expected ';' after variable declaration.@ 2 ms Source: eval@[native code] http://elementary.local/wp-content/plugins/elementary/tests/tests.bundle.js:96645:212 rewire@http://elementary.local/wp-content/plugins/elementary/tests/tests.bundle.js:80671:40 beforeEach@http://elementary.local/wp-content/plugins/elementary/tests/tests.bundle.js:96316:40

I get this error when loading by Qunit tests. These same tests were running a few weeks back. Some dependency update should have caused the problems I guess, but for the life of me I can figure out which one.

could updates in webpack, babel, Qunit, react, etc cause this?