avoid-importing-barrel-files.md

Avoid importing barrel files

Rule Details

This rule aims to avoid importing barrel files that lead to loading large module graphs. This rule is different from the avoid-barrel-files rule, which lints against authoring barrel files. This rule lints against importing barrel files.

Examples of incorrect code for this rule:

// If `foo` is a barrel file leading to a module graph of more than 20 modules
export { foo } from 'foo';

Configuration

This rule takes an optional configuration:

{
  "rules": {
    "barrel-files/avoid-importing-barrel-files": [
      2,
      {
        "maxModuleGraphSizeAllowed": 40,
        "amountOfExportsToConsiderModuleAsBarrel": 5,
        "exportConditions": ["node", "import"],
        "mainFields": ["module", "main", "browser"],
        "extensions": [".js", ".ts", ".json", ".node"],
        "tsconfig": {
          "configFile": "./tsconfig.json",
          "references": []
        }
      }
    ]
  }
}

Path Aliases

The rule can accept an alias option whose value can be an object that matches Webpack's resolve.alias configuration.

// .eslintrc.cjs
const path = require('path')

module.exports = {
  // ...
  "rules": {
    "barrel-files/avoid-importing-barrel-files": [
      2,
      {
        alias: {
          // "@/foo/bar.js" => "./src/foo/bar.js"
          "@": [path.resolve(".", "src")]
        }
      }
    ]
  }
}