egghead.io lesson 11: Creating async producers (and why you shouldn’t)
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It is allowed to return Promise objects from recipes. Or, in other words, to use
async / await. This can be pretty useful for long running processes, that only produce the new object once the promise chain resolves. Note that
produce itself (even in the curried form) will return a promise if the producer is async. Example:
Warning: please note that the draft shouldn't be 'leaked' from the async process and stored else where. The draft will still be revoked as soon as the async process completes.
finishDraft are two low-level functions that are mostly useful for libraries that build abstractions on top of immer. It avoids the need to always create a function in order to work with drafts. Instead, one can create a draft, modify it, and at some time in the future finish the draft, in which case the next immutable state will be produced. We could for example rewrite our above example as:
finishDraft takes a
patchListener as second argument, which can be used to record the patches, similarly to
Warning: in general, we recommend to use
produce instead of the
produce is less error prone in usage, and more clearly separates the concepts of mutability and immutability in your code base.