eslint-plugin-nestjs-leading-slash

ESLint plugin to enforce the use of leading slash in NestJS route decorators.

Description

This ESLint plugin validates that all routes defined in NestJS HTTP decorators (@Get(), @Post(), @Put(), @Patch(), @Delete(), @Options(), @Head(), @All()) start with a leading slash (/). This helps maintain consistency in your NestJS application routes and prevents common errors.

Installation

npm install --save-dev eslint-plugin-nestjs-leading-slash

Usage

Legacy Configuration (.eslintrc.js or .eslintrc.json)

{
  "plugins": ["nestjs-leading-slash"],
  "rules": {
    "nestjs-leading-slash/enforce-leading-slash": "error"
  }
}

Flat Config (eslint.config.js)

import nestjsLeadingSlash from "eslint-plugin-nestjs-leading-slash";

export default [
  {
    plugins: {
      "nestjs-leading-slash": nestjsLeadingSlash,
    },
    rules: {
      "nestjs-leading-slash/enforce-leading-slash": "error",
    },
  },
];

Rules

enforce-leading-slash

Enforces that all routes in NestJS HTTP decorators start with a leading slash.

Valid code examples

class UsersController {
  @Get("/users")
  getUsers() {}

  @Post("/api/users")
  createUser() {}

  @Put("/users/:id")
  updateUser() {}

  @Delete("/users/:id")
  deleteUser() {}

  @Get()
  getDefault() {}

  @Get("/")
  getRoot() {}

  @Get("")
  getEmpty() {}
}

Invalid code examples

class UsersController {
  @Get("users") // ❌ Missing leading slash
  getUsers() {}

  @Post("api/users") // ❌ Missing leading slash
  createUser() {}

  @Put("users/:id") // ❌ Missing leading slash
  updateUser() {}
}

Auto-fix

This rule is auto-fixable. ESLint can automatically fix errors by adding the leading slash:

// Before
@Get('users')

// After (auto-fix)
@Get('/users')

Supported decorators

• @Get()
• @Post()
• @Put()
• @Patch()
• @Delete()
• @Options()
• @Head()
• @All()

Special cases

• Routes without arguments: If the decorator has no arguments (e.g., @Get()), it is considered valid since NestJS uses '/' by default.
• Empty routes: Empty routes ('') or with only / are considered valid.
• Template literals: Simple template literals without variables are supported (e.g., `users`).

License

MIT

Contributing

Contributions are welcome. Please open an issue or a pull request in the repository.