Escape JS try-catch hell with Untry

Error handling is a crucial aspect of software development, ensuring applications remain stable and user-friendly. However, managing errors in JavaScript can be cumbersome and time-consuming. That's where Untry comes in – a lightweight library that simplifies error handling.

JavaScript error handling.

JavaScript error handling relies on try-catch blocks, which can become unwieldy and difficult to manage, especially when dealing with nested asynchronous calls. This approach can lead to:

• Unhandled errors slipping through the cracks
• Difficulty in cleaning up resources after errors occur
• Code cluttered with error handling logic

Overly complex and deeply nested try-catch blocks creates a maintenance nightmare. By attemptin to handle errors using multiple layers of try-catch statements leads to code obfuscation, error masking, and swallowed exceptions. Asynchronous code and callbacks exacerbate the problem.

Let´s see an example of how complex can become try-catch error handling in JavaScript. Taking an eCommerce API endpoint that fetches product details:

app.get('/product/:id', async (req, res) => {
   try {
      const product = await fetchProduct(req.params.id)
      const reviews = await fetchReviews(req.params.id)
      res.json({ product, reviews })
   } catch (error) {
      res.status(500).send('Something went wrong!')
   }
});

If either fetchProduct or fetchReviews fails it will return the same generic response.

Let's refactor in a way that we can handle errors individually for each async call, and decide what to do in each case:

app.get('/product/:id', async (req, res) => {
   let product
   let reviews
   let productError
   let reviewsError

   // product
   try {
      product = await fetchProduct(req.params.id)
   } catch (error) {
      productError = error
   }

   if (productError) {
      res.status(500).json({ error: productError })
      return
   }

   // reviews
   try {
      reviews = await fetchReviews(req.params.id)
   } catch (error) {
      reviewsError = error
   }

   if (reviewsError) {
      res.status(500).json({ error: reviewsError })
      return
   }

   // final response
   res.json({ product, reviews })
})

Now the code handles each case separately, although it seems less readable and therefore less maintainable.

Let's make it possible to handle each case separately without sacrificing much readability by using Untry:

app.get('/product/:id', async (req, res) => {
   let [product, productError] = await untry(() => fetchProduct(req.params.id))
   if (productError) {
      res.status(500).json({ error: productError })
      return
   }

   let [reviews, reviewsError] = await untry(() => fetchReviews(req.params.id))
   if (reviewsError) {
      res.status(500).json({ error: reviewsError })
      return
   }

   res.json({ product, reviews })
})

What is Untry?

Untry is a lightweight JavaScript library inspired by Go's error handling philosophy. This approach eliminates the try-catch flow. Allows the explicit error management using error as value, not as exception.

How Untry Works

Untry executes a function, catches any error inside, and returns an array containing the resulting value and any thrown error. It is a simple solution for managing errors, making your code more robust, readable, and maintainable.

import untry from 'untry';

let [value, error] = untry(() => {
  // code that might throw an error
});

Key Benefits

• Simplified error handling
• Explicit error management
• Easy cleanup on failure
• Customizable error handling
• Streamline Your Development

With Untry, you can:

• Write more robust code
• Reduce error handling boilerplate
• Escape try-catch hell

NPM Package: https://www.npmjs.com/package/untry