fix: support jest config function

[panjiesw]

fixes #126

Type of change

• Bug fix (change which fixes an issue)
• New feature or functionality (change which adds functionality)
• Style (white-space, formatting, etc...)
• Refactor (a code change that neither fixes a bug or adds a new feature)
• Performance (a code change that improves performance)
• Documentation (updates to documentation or READMEs)
• Chore (any other change that doesn't affect source or test files)

For changes visible to end-users

• Breaking change (this change will force users to change their own code or config)
• Relevant documentation has been updated
• Suggested release notes are provided below:

Test plan

How has this been tested?

• Covered by existing test cases
• New test cases added
• Manual testing

If part of the test plan included manual testing, please provide instructions so we can reproduce.
Please also list any relevant details for your test configuration.

[CLAassistant]

All committers have signed the CLA.

[jbedard]

Awesome 👍 🎉

Anything still in progress or is it good to go?

[panjiesw]

@jbedard no pending changes, good to go from me 🙂

[panjiesw]

@jbedard any chance of a new release that will include this soon?

[jbedard]

Done 👍