eslint-plugin-cflint

1.0.0 verified Sat Apr 25 auth: no javascript

ESLint plugin providing two custom CloudFlare-specific linting rules: `no-substr` (prevents use of `String.prototype.substr`, considered legacy) and `no-this-assignment` (prevents assigning `this` to a variable). Current stable version is 1.0.0, initially released with no further updates. It requires ESLint as a peer dependency. Differentiators: lightweight and focused exclusively on patterns flagged internally by CloudFlare; minimal setup and no extra dependencies. Release cadence: single release, no maintenance indicated.

Common errors

error ESLint: Failed to load plugin 'cflint': Cannot find module 'eslint-plugin-cflint' ↓

cause Plugin not installed or ESLint cannot locate it.

fix

Run npm install eslint-plugin-cflint --save-dev and ensure node_modules contains the package.

error ESLint: Configuration for rule "cflint/no-substr" is invalid. Severity should be one of: 0, 1, 2, "off", "warn", "error". ↓

cause Incorrect rule severity value in ESLint config.

fix

Use 'error', 'warn', 'off' (or 2, 1, 0) as rule values.

Warnings

gotcha Plugin has only two rules; may not meet expectations for broader linting. ↓

fix Review the rules list; supplement with other ESLint plugins if needed.

gotcha Rules are deprecated within CloudFlare; no longer actively maintained. ↓

fix Consider using built-in ESLint rules like 'no-restricted-properties' for substr.

gotcha Plugin does not provide any shared configs (e.g., 'recommended'). Must be manually configured. ↓

fix Add 'cflint/no-substr' and 'cflint/no-this-assignment' manually to rules.

Install

npm install eslint-plugin-cflint

yarn add eslint-plugin-cflint

pnpm add eslint-plugin-cflint

Imports

plugin
wrong
```
const plugin = require('eslint-plugin-cflint')
```
correct
```
import plugin from 'eslint-plugin-cflint'
```
ESM import works if project supports it; CommonJS require also works since plugin exports a single object.

rules

wrong

const { rules } = require('eslint-plugin-cflint')

correct

import { rules } from 'eslint-plugin-cflint'

Named export for rules object, can be used in custom config.

configs
```
import { configs } from 'eslint-plugin-cflint'
```
Configs export is provided as an object; not commonly used.

Quickstart

Configuration to enable both CloudFlare rules and examples of code that triggers them.

// .eslintrc.js
module.exports = {
  plugins: ['cflint'],
  rules: {
    'cflint/no-substr': 'error',
    'cflint/no-this-assignment': 'error'
  }
};

// Example code that will be flagged:
let s = 'hello';
console.log(s.substr(0, 2)); // Error: no-substr

let self = this; // Error: no-this-assignment