Uses deprecated core-js version 2.6.11

[eliorivero]

Hi, testcafe looks really cool so I wanted to try it. As soon as I yarn added it though, I got these messages:

warning testcafe > babel-runtime > core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
warning testcafe > testcafe-legacy-api > babel-runtime > core-js@1.2.7: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
warning testcafe > babel-core > babel-register > core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.

I knew something would be broken and indeed my app no longer compiles. As soon as I install testcafe I start getting a bunch of errors like this:

ERROR in ./app/App.js
Module not found: Error: Can't resolve 'core-js/modules/es.array.concat' in '/Users/xxx/Sites/xxx/app'
 @ ./app/App.js 4:0-41
 @ ./app/main.js
 @ multi ./app/main.js

This is happening because testcafe requires core-js@2.6.11 that's no longer maintained and my app is setup to use the most up to date core-js@3.6.5.

I really wanted to use testcafe since it looks very nice. Hope this issue can be addressed soon.

[miherlosev]

Hi @eliorivero

Module not found: Error: Can't resolve 'core-js/modules/es.array.concat' in '/Users/xxx/Sites/xxx/app'

This behavior is unexpected. Could you please share an example with which we can reproduce the problem locally?