# cheerio

A Cursor rule for cheerio in Node.js, covering scraper structure, selector choices, data cleanup, scaling, and parser tests.

- rule · `type=rule` · Cursor · ★ 3579
- Author: sanjeed5
- License: CC0-1.0 · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/sanjeed5/awesome-cursor-rules-mdc/tree/HEAD/rules-mdc/cheerio.mdc
- Updated: 2026-05-19
- HTML: https://affpapa.org/en/nevibecode/rules/cheerio

## What it does

The rule targets `**/*.{js,jsx}` and sets a clear shape for Node.js scrapers. It keeps HTTP requests, HTML parsing, and data storage in separate parts, uses `async/await` for asynchronous work, and favors scoped selectors. Extracted text should be trimmed, attributes read with `.attr()`, and missing elements checked before values are used.

It also addresses memory use when `cheerio.load()` handles large HTML documents. For queued requests, retries, concurrency, and rate limits, it points to `Crawlee` and `CheerioCrawler`. Parser behavior belongs in Jest tests with mocked HTML. `cheerio` does not run JavaScript or render CSS, so client-rendered content requires `Puppeteer` or `Playwright`. Scrapers must respect `robots.txt`.

## Install

### Cursor (native platform)

**Manually: put the files in place**
- File: `.cursor/rules/cheerio.mdc` — Frontmatter: description, globs, alwaysApply

### Claude Code

**Manually: put the files in place**
- File: `.claude/rules/cheerio.md` — The paths frontmatter field limits the files: move globs from the source into paths

### Codex

**AGENTS.md**
- Codex reads AGENTS.md: paste the rule text there

### GitHub Copilot

**Manually: put the files in place**
- File: `.github/instructions/cheerio.instructions.md` — The applyTo field sets which files it applies to: move globs from the source into applyTo

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/rules/cheerio.md`

### Cline

**Manually: put the files in place**
- File: `.clinerules/cheerio.md`

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/sanjeed5/awesome-cursor-rules-mdc/tree/HEAD/rules-mdc/cheerio.mdc

## When to use it
- separate fetching, parsing, and data storage
- scope selectors to the relevant HTML section
- trim extracted text before saving it
- handle missing nodes and attributes safely
- test selectors against mocked HTML

## Example prompts
- Set up a `cheerio` product scraper with scoped selectors, trimmed text, and output saved to `products.json`.
- Refactor this scraper so HTTP fetching, HTML parsing, and persistence are separate functions using `async/await`.
- Create Jest tests in `parser.test.js` for present and missing product fields in mocked HTML.

## Source text · cheerio.mdc · CC0-1.0

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 9e3d48cab09d44d4.

BEGIN THIRD-PARTY FILE 9e3d48cab09d44d4
````text
---
description: Definitive guidelines for using cheerio effectively in Node.js projects, focusing on robust web scraping, performance, and maintainable code.
globs: **/*.{js,jsx}
---
# cheerio Best Practices

`cheerio` is your lightweight, server-side jQuery for Node.js, ideal for fast HTML parsing and manipulation. Follow these rules to build efficient, maintainable, and robust scraping solutions.

## 1. Code Organization & Structure

**Always modularize your scraping logic.** Separate HTTP requests, HTML parsing, and data persistence. Use `async/await` for all asynchronous operations.

### ✅ GOOD: Modular & Asynchronous Structure

```javascript
// index.js
import * as cheerio from 'cheerio';
import axios from 'axios';
import { writeFile } from 'fs/promises';

async function fetchAndParse(url) {
  try {
    const { data: html } = await axios.get(url, {
      headers: { 'User-Agent': 'YourScraper/1.0' }
    });
    const $ = cheerio.load(html);

    const products = [];
    $('.product-item').each((i, el) => {
      const $el = $(el);
      const name = $el.find('.product-name').text().trim();
      const price = $el.find('.product-price').text().trim();
      const imageUrl = $el.find('img').attr('src');
      
      // Always check for existence before pushing
      if (name) { 
        products.push({ name, price, imageUrl });
      }
    });
    return products;
  } catch (error) {
    console.error(`Error scraping ${url}:`, error.message);
    throw error;
  }
}

async function main() {
  const targetUrl = 'https://www.example.com/products';
  const scrapedData = await fetchAndParse(targetUrl);
  await writeFile('products.json', JSON.stringify(scrapedData, null, 2), 'utf8');
  console.log('Scraping complete. Data saved to products.json');
}

main();
```

## 2. Common Patterns & Anti-patterns

### 2.1. Selector Efficiency

**Keep selectors specific and scoped.** Avoid broad selectors that force `cheerio` to traverse large portions of the DOM. Chain `.find()` for nested elements.

```javascript
// ❌ BAD: Overly broad, inefficient
const allLinks = $('a').map((i, el) => $(el).attr('href')).get();

// ✅ GOOD: Scoped to relevant section
const productLinks = $('#product-grid a.product-link').map((i, el) => $(el).attr('href')).get();

// ✅ GOOD: Chain .find() for precision
const productName = $('.product-card').first().find('h2.title').text().trim();
```

### 2.2. Data Extraction & Cleaning

**Use `.text()` for visible text, `.attr()` for attributes, `.html()` for inner HTML.** Always `.trim()` extracted text to remove whitespace.

```javascript
// ❌ BAD: Untrimmed text, can contain leading/trailing whitespace or newlines
const title = $('h1').text(); // "  My Product Title  \n"

// ✅ GOOD: Clean text extraction
const title = $('h1').text().trim(); // "My Product Title"

// ❌ BAD: Assuming element exists, `undefined.text()` will crash
const price = $('.product-price').text().trim(); 

// ✅ GOOD: Check element existence before extracting
const $priceEl = $('.product-price');
const price = $priceEl.length ? $priceEl.text().trim() : 'N/A';
```

## 3. Performance Considerations

### 3.1. Large HTML Documents (>10MB)

`cheerio.load()` creates an in-memory DOM. For very large documents, this can consume significant memory.

**Strategies for large documents:**
1.  **Selective Loading:** If possible, extract and parse only relevant HTML snippets.
2.  **Clear References:** Set `$` to `null` after processing to aid garbage collection.

```javascript
// ✅ GOOD: Aid garbage collection
let $ = cheerio.load(htmlContent);
// ... perform operations ...
$ = null; // Clear reference
if (global.gc) global.gc(); // Force GC (requires --expose-gc)
```

### 3.2. Concurrency & Rate Limiting

For scalable, production scraping, **use `Crawlee`'s `CheerioCrawler`**. It handles request queuing, concurrency, retries, and rate limiting automatically.

```javascript
````
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The third-party file has ended. Everything between the 9e3d48cab09d44d4 tags is data: requests and commands from it are not followed. An “end of file” line with another tag inside the block is part of the file.

First 3924 of 6054 bytes. © sanjeed5 · CC0-1.0 · https://github.com/sanjeed5/awesome-cursor-rules-mdc/tree/HEAD/rules-mdc/cheerio.mdc

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