Node.js Async Function Best Practices
- Since Node.js version 7.6, Node.js ships with a new V8 version that features async functions.
- As Node.js 8 becomes the active LTS version on October 31, there is no reason for not starting to adopt async functions in your codebase.
- In this article, I will briefly show you what async functions are, and how they change the way we write Node.js applications.
- To do so, you can use the built-in method: – – As supports Promises out of the box, using functions with express is as simple as: – – Edit 1: as Keith Smith pointed out, the above example has a serious issue – if the Promise gets rejected, the route…
- To fix this issue, you should wrap your async handlers in a function that handles errors: – – Imagine you are working on something similar, when an operation needs two inputs, one from a database, and one from an external service: – – In this case, what will happen is…
Mastering async functions in Node.js – error handling, parallel execution and complex control flows
Since Node.js version 7.6, Node.js ships with a new V8 version that features async functions. As Node.js 8 becomes the active LTS version on October 31, there is no reason for not starting to adopt async functions in your codebase. In this article, I will briefly show you what async functions are, and how they change the way we write Node.js applications.
functions let you write -based code as if it were synchronous. Once you define a function using the keyword, then you can use the keyword within the function’s body. When the function is called, it returns with a . When the function returns a value, the gets fulfilled, if the function throws an error, it gets rejected.
The keyword can be used to wait for a to be resolved and returns the fulfilled value. If the value passed to the keyword is not a Promise, it converts the value to a resolved .
If your Node.js applications are already using s, then you only have to start ing your Promises, instead of chaining them.
If your applications are built using callbacks, moving to functions should be done gradually. You can start adding new features by using this new technique. If you have to use older parts of the application, you can simply wrap them into Promises.
To do so, you can use the…