Rollup + TypeScript + source maps + .d.ts files

package.json.example

{
  ...
  "source": "src/index.ts",
  "main": "dist/main.cjs",
  "module": "dist/module.mjs",
  "types": "dist/index.d.ts",
  "scripts": {
    "dev": "rollup -w -c",
    "build": "rollup -c",
    "prepack": "yarn run build",
    "test": "jest"
  },
  "devDependencies": {
    "@rollup/plugin-typescript": "^8.3.1",
    "rollup": "^2.70.1",
    "rollup-plugin-delete": "^2.0.0",
    "rollup-plugin-dts": "^4.2.0",
    "rollup-plugin-sourcemaps": "^0.6.3",
    "tslib": "^2.3.1",
    "typescript": "^4.6.2",
  },
  "packageManager": "yarn@3.2.0"
}

rollup.config.js

import typescript from "@rollup/plugin-typescript";
import sourcemaps from "rollup-plugin-sourcemaps";
import dts from "rollup-plugin-dts";
import del from "rollup-plugin-delete";

export default [
  {
    input: "src/index.ts",
    output: [
      {
        sourcemap: "inline",
        file: "dist/main.cjs",
        format: "cjs"
      },
      {
        sourcemap: "inline",
        file: "dist/main.mjs",
        format: "es"
      },
    ],
    plugins: [
      typescript({ sourceMap: true, inlineSources: true, tsconfig: "./tsconfig.json" }),
      sourcemaps(),
    ],
  },
  {
    input: "dist/types/index.d.ts",
    output: [{
      file: "dist/index.d.ts",
      format: "es",
      plugins: []
    }],
    plugins: [      
      dts(),
      del({ targets: "dist/types", hook: "buildEnd" })
    ],
  }
];

tsconfig.json

{
  "compileOnSave": false,
  "compilerOptions": {
    "target": "es2015",
    "moduleResolution": "node",
    "strict": true,
    "declaration": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "sourceMap": true,
    "importHelpers": true,
    "skipLibCheck": true,
    "resolveJsonModule": true,
    "declarationDir": "./types" # NB this is inside the /dist dir as per rollup config!
  },  
  "include": [
    "src/**/*.ts",
    "types/globals.d.ts",
  ],
  "exclude": [
    "**/__tests__/*",
    "**/__mocks__/*"
  ]
}