Rework configuration

[mkcode]

Summary: Jest has a very rich configuration which has accumulated a few years worth of additions. While this configuration works very well for those familiar with it, it has an overly large API surface which is daunting for people to approach, and changing config can often be an exercise in frustration. In addition to the approachability, the many different options also makes Jest’s internals and its behavior harder to reason about, as there are many ways to achieve the same thing. Jest should look into what ways configuration can be simplified so it’s easier to write, read, maintain and reason about. Jest also needs to provide a clear migration path for current configurations, either in Jest itself or some other tool so people are not forced to migrate manually.

• Issue: Simplifying configuration · Issue Simplifying configuration jestjs/jest#7185 · facebook/jest

Level of complexity: Medium

Experience wanted:

• JavaScript
• Jest testing framework

Deliverables:

• Design a new configuration model to satisfy the needs laid out in the summary
• Implement this new model
• Provide a migration path for current users - both via documentation and tooling