Understanding the toPromise() Deprecation
Explore the reasons behind the deprecation of the toPromise method in RxJS 7. Understand the differences between promises and observables, and learn how to use firstValueFrom and lastValueFrom as improved alternatives to convert observables into promises while handling errors and empty streams effectively.
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One of the major deprecations of RxJS 7 is toPromise(), which will be deleted permanently after the release of RxJS 8. So it’s highly recommended that we avoid using toPromise() in future development.
Now let’s give a little bit of background to understand the reason behind this deprecation. It’s important to understand the use case of toPromise(), why this particular method is available, and when to use it. Additionally, it’s important to understand the incoherent behavior of this method in RxJS 6 in order to anticipate problems that might arise.
What is a promise?
Promises are used by many developers nowadays, and there are thousands of promise-based libraries. A promise is an object that holds the result (or failure) of an asynchronous operation.
Promises have been available in JavaScript through ...