Should componentDidMount optionally return a promise?

[patsplat]

Do you want to request a feature or report a bug?

Feature Request

What is the current behavior?

Currently, componentDidMount returns nothing. It is the recommended lifecycle hook for performing async operations. It is necessary to create wrapper functions returning a promise to test such operations (#14687).

What is the expected behavior?

Unlike the suggestion in #1739 etc do not recommending changing any rendering semantics. Simply allow a promise to be returned so that testing does not require boilerplate.

[kambleaa007]

Do anybody knows steps to solve this feature, im ready to work on it

[patsplat]

Have been discussing and exploring this feature in my applications.

Am leaning towards making this more a documentation change, ie updating the website to illustrate patterns for retaining and testing a ref to a Promise.

If React doesn't use the promise, can see a pragmatic argument against changing the signature of the method.

Downstream libraries such as linting etc would have to be updated, which seems a high cost.