signaltree rollup-entry-points.instructions.md

Nx Rollup additionalEntryPoints - Filename Collision Issue

The Problem

When using @nx/rollup:rollup executor with additionalEntryPoints, if multiple entry points have the same filename (e.g., all named index.ts), Rollup will output them with the same name, causing files to overwrite each other.

Example of the Problem

// project.json - THIS CAUSES PROBLEMS
{
  "build": {
    "executor": "@nx/rollup:rollup",
    "options": {
      "main": "packages/events/src/index.ts",
      "additionalEntryPoints": [
        "packages/events/src/nestjs/index.ts",   // Output: index.esm.js
        "packages/events/src/angular/index.ts",  // Output: index.esm.js (OVERWRITES!)
        "packages/events/src/testing/index.ts"   // Output: index.esm.js (OVERWRITES!)
      ]
    }
  }
}

Result: Only one index.esm.js survives. The other subpaths are broken.

The Solution

Create uniquely-named barrel files at the package root that re-export from the subdirectory:

1. Create Barrel Files

// packages/events/src/nestjs.ts
/**
 * @signaltree/events/nestjs
 * Re-export barrel for NestJS integration.
 */
export * from './nestjs/index';

// packages/events/src/angular.ts
export * from './angular/index';

// packages/events/src/testing.ts
export * from './testing/index';

2. Update project.json

{
  "build": {
    "executor": "@nx/rollup:rollup",
    "options": {
      "main": "packages/events/src/index.ts",
      "additionalEntryPoints": [
        "packages/events/src/nestjs.ts",   // Output: nestjs.esm.js ✓
        "packages/events/src/angular.ts",  // Output: angular.esm.js ✓
        "packages/events/src/testing.ts"   // Output: testing.esm.js ✓
      ]
    }
  }
}

3. Update package.json exports

{
  "exports": {
    ".": {
      "types": "./index.d.ts",
      "import": "./index.esm.js"
    },
    "./nestjs": {
      "types": "./nestjs.d.ts",
      "import": "./nestjs.esm.js"
    },
    "./angular": {
      "types": "./angular.d.ts",
      "import": "./angular.esm.js"
    },
    "./testing": {
      "types": "./testing.d.ts",
      "import": "./testing.esm.js"
    }
  }
}