Rollup does not bundle declaration file

Question

I am trying to build a library made with TypeScript. I am using the paths property in tsconfig.json.

My tsconfig.json looks like this:

{
  "compilerOptions": {
    "module": "es2015",
    "moduleResolution": "node",
    "target": "es2015",
    "noImplicitAny": true,
    "removeComments": true,
    "preserveConstEnums": true,
    "experimentalDecorators": true,
    "sourceMap": true,
    "lib": [
      "esnext",
      "dom"
    ],
    "strict": true,
    "sourceRoot": "./src",
    "rootDir": "./src",
    "outDir": "build",
    "declaration": true,
    "declarationDir": "build",
    "baseUrl": "./src",
    "noUnusedLocals": true,
    "paths": {
      "modules/*": [
        "modules/*"
      ],
      "common/*": [
        "common/*"
      ]
    }
  },
  "exclude": [
    "node_modules",
    "build"
  ]
}

And my rollup config looks like this:

import typescript from 'rollup-plugin-typescript2'

export default {
  entry: "./src/index.ts",
  output: {
    file: './build/index.js',
    format: 'cjs'
  },
  plugins: [
    typescript({ typescript: require("typescript"), declaration: true, clean: true })
  ]
}

However, when I build using rollup -c, it creates this in my build folder:

Where the index.js is bundled just fine, but the declaration file here simply imports from the /common folder and that folder basically contains all the other folders from the src directory but only with a single declaration file per folder, furthermore, these files try to import using the paths aliases instead of being built with relative imports, so they do not work.

How do I tell rollup to build a single declaration file instead of this?

Answer 1

rollup-plugin-typescript keeps the folder structure for declaration files. To bundle the declaration too, you should use rollup-plugin-ts as well: https://github.com/wessberg/rollup-plugin-ts