eslint-plugin-force-barrel-imports

eslint-plugin-force-barrel-imports

This ESLint plugin adds a single rule force-barrel-imports that prevents importing a JavaScript/TypeScript file directly if it has a parent barrel file (index.js/index.ts). This helps enforce internal modularization of projects and promote file-level visibility control.

Consider the following file structure for example:

root
├ module1
│ ├ index.ts
│ └ private1.ts
│
├ module2
│ ├ index.ts
│ └ private2.ts
│
└ top.ts

The rule will forbid directly importing private1.ts file from outside of module1 folder. Symbols defined in private1.ts can only be accessed from top.ts and private2.ts if they are re-exported from module1/index.ts.

Rule allows reaching to parent files. In this case, both private1.ts and private2.ts can reach to top.ts. Reaching to parent index.ts is not allowed.

Modules can contain other modules, in this case same rules apply.

root
├ module1
│ ├ module3
│ │ ├ index.ts
│ │ └ private3.ts
│ │
│ ├ index.ts
│ └ private1.ts
│
├ module2
│ ├ index.ts
│ └ private2.ts
│
└ top.ts

• private1.ts can reach to module3/index.ts but not to private3.ts
• private3.ts can reach to private1.ts, module2/index.ts and top.ts
• top.ts can reach to module1/index.ts and module2/index.ts, but not to any of the private*.ts files

Installation

This plugin depends on the resolver logic from eslint-plugin-import, so it has to be installed too along with the required resolvers.

npm install --save-dev \
  eslint-plugin-force-barrel-imports \
  eslint-plugin-import \
  eslint-import-resolver-node \
  eslint-import-resolver-typescript

Enable both plugins, resolvers, and the force-barrel-imports rule in the eslint config of your project (.eslintrc.json):

{
  "plugins": [
    "import",
    "force-barrel-imports"
  ],
  "rules": {
    "force-barrel-imports/force-barrel-imports": "error"
  },
  "settings": {
    "import/resolver": {
      "typescript": true,
      "node": true
    }
  }
}

If you are not using TypeScript, eslint-import-resolver-typescript and "typescript": true should be omitted.