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⚠️ This article was written in 2021. Some content may be outdated.

JavaScript Async Patterns Overview

JavaScript async patterns come up often in daily work, so I've put together a systematic roundup, hoping it helps everyone understand and apply them better.

Basic Concepts ​

We can implement it like this:

javascript
// 使用示例
import { createApp } from './app'

const config = {
  apiBase: process.env.API_BASE || '/api',
  timeout: 10000,
  retries: 3
}

const app = createApp(config)
app.mount('#root')

This pattern improves the code's maintainability.

Core Implementation ​

See the following code for specific usage:

javascript
// 工具函数封装
function createHandler(options = {}) {
  const { timeout = 5000, retries = 3 } = options

  return async function execute(url, data) {
    for (let attempt = 0; attempt < retries; attempt++) {
      try {
        const controller = new AbortController()
        const timer = setTimeout(() => controller.abort(), timeout)
        const res = await fetch(url, {
          method: 'POST',
          body: JSON.stringify(data),
          signal: controller.signal
        })
        clearTimeout(timer)
        return await res.json()
      } catch (err) {
        if (attempt === retries - 1) throw err
      }
    }
  }
}

It is recommended to unify conventions within the team to reduce inconsistency.

Practical Application ​

Let's look at the specific implementation:

javascript
// 核心实现
const processData = (input) => {
  return input
    .filter(item => item.active)
    .map(item => ({
      ...item,
      displayName: item.name.trim(),
      timestamp: Date.now()
    }))
    .sort((a, b) => b.timestamp - a.timestamp)
}

This implementation is concise and efficient, suitable for most scenarios.

Best Practices ​

Here is a practical example:

javascript
// 使用示例
import { createApp } from './app'

const config = {
  apiBase: process.env.API_BASE || '/api',
  timeout: 10000,
  retries: 3
}

const app = createApp(config)
app.mount('#root')

In real projects, you need to make appropriate adjustments based on specific requirements.

Common Issues ​

The core code is as follows:

javascript
// 工具函数封装
function createHandler(options = {}) {
  const { timeout = 5000, retries = 3 } = options

  return async function execute(url, data) {
    for (let attempt = 0; attempt < retries; attempt++) {
      try {
        const controller = new AbortController()
        const timer = setTimeout(() => controller.abort(), timeout)
        const res = await fetch(url, {
          method: 'POST',
          body: JSON.stringify(data),
          signal: controller.signal
        })
        clearTimeout(timer)
        return await res.json()
      } catch (err) {
        if (attempt === retries - 1) throw err
      }
    }
  }
}

Be sure to handle edge cases and exceptions properly.

Summary ​

  • Keep up with community trends and update your technical approach accordingly
  • Performance optimization should be based on real data; avoid over-optimizing
  • The core of JavaScript async patterns is understanding the underlying principles, not just memorizing APIs
  • In real projects, choosing the right approach matters more than chasing the latest technology

MIT Licensed