Is `.then(function(a){ return a; })` a No-Op in Promises?

Understanding the Function of ".then(function(a){ return a; })" on Promises

In the realm of JavaScript programming, promises provide a robust mechanism for handling asynchronous operations. The .then() method allows developers to chain operations based on the outcome of a preceding promise. However, a common question arises: is the following code snippet a no-op for promises?

.then(function(a){ return a; })

Analysis: A Useless No-Op

Yes, the code snippet is essentially a no-op. It serves no practical purpose within the promise chain. The function passed to .then() does nothing more than return the input it receives. Consequently, the promise returned by .then() contains the same value as the input promise, offering no added value to the chain.

Why the Author May Have Implemented It

The inclusion of this no-op in the tutorial example is likely an oversight or a misunderstanding of how promises operate. Promises are designed to enable chaining of operations in an asynchronous fashion, and the no-op defeats this purpose by simply replicating the fulfillment value of the preceding promise.

Removal Recommended

For clarity and efficiency, it is advisable to omit the no-op from promise chains. The following code provides the equivalent functionality without the unnecessary addition:

.fetch({withRelated: ['events'], require: true})

Conclusion

The code snippet ".then(function(a){ return a; })" is a redundant and unnecessary addition to promise chains. It does not contribute any meaningful functionality and should be removed to maintain simplicity and efficiency in asynchronous code handling.

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