Allow ast transformer to specify options

[longlho]

🚀 Feature Proposal

Right now ast transformers only take in a path to the transformer factory but not further options. Our transformer has a lot of options but we have no idea how to pass those in other than creating a wrapper

Motivation

Example

// jest.config.js
module.exports = {
  // [...]
  globals: {
    'ts-jest': {
      astTransformers: {
        before: [{
			path: '@formatjs/ts-transformer',
			options: {}
		}],
      },
    }
  }
};

[ahnpnl]

At the moment, ts-jest only cares about the factory function which is passed in by users, see https://github.com/kulshekhar/ts-jest/blob/master/src/config/config-set.ts#L440 . When user defines the transformer path, ts-jest simply performs require on the path and then call factory. It doesn’t know anything about the context inside factory.

I think it is not possible now to have a feature like you request. Do you see other ways to apply your feature request by looking at the current codes ?