BabelConfig with rootMode: "upward" not loading babel config files

A simple monorepo with the following config:

// package/ui/jest.config.js

{
  globals: {
    "ts-jest": {
      babelConfig: {
        rootMode: "upward"
    }
  },
  preset: "ts-jest",
  transform: {
    "^.+\\.jsx?$": ["babel-jest", { rootMode: "upward" }]
  }
}

When I run yarn test it works as expected. When I run yarn lerna run test, ts-jest fails to load babel configs. If I use babel-jest instead of ts-jest, it works fine. The only way to make it work is to manually pass the entire babel config to globals[ts-jest].babelConfig.

Maybe something like globals[ts-jest].babelConfig.babelrc: true would be nice in such case to allow loading configs. It didn’t worked with globals[ts-jest].babelConfig: true

Minimal repo

https://github.com/arvigeus/monotest

[arvigeus]

Isn’t it possible to delegate this to babel-jest when it comes to it? Otherwise you are reimplementing logic. I am thinking about some general solution, not just my problem in particular.

[ahnpnl]

what I can see from the log is actually babelrc wasn’t loaded but only root babel config is loaded (you can search for "plugins" in your log).

So the main issue here is ts-jest doesn’t know about your babelrc in subpackages because ts-jest babel config is on global level. So when you specify ts-jest config to use babel, it only searches in the root folder (by default) or it searches based on specifying string path or use require. ts-jest doesn’t search for the whole project to find other babel config. Therefore it throws the error like you saw.

So temporarily workaround is you copy the content of babel config in your subpackages and paste to ts-jest babel config, for example:

globals: {
    'ts-jest': {
      babelConfig: {
        'plugins': [
          [
            'macros',
            {
              'styledComponents': {
                'pure': true,
              },
            },
          ],
        ],
        rootMode: 'upward',
      },
    },
  },

The question here is how does ts-jest know when to search for the whole project to find other babel configs. The idea of providing a subpackage babel config is the easiest implementation, but is it a good way to go ?

What do you think @kulshekhar ? I think perhaps for loading babel config, if user specifies rootMode: 'upward' we can somehow look for babel config in the whole project based on ? But this will create a question is how to find the config in subpackages quickly, can we rely on babelrcRoots in the root babel config ?