@sagar-oi/toast v0.1.6

 npm i react typescript @types/react tslib --save-dev

npx tsc -init

{
  "compilerOptions": {
    "target": "es5",
    "lib": ["dom", "dom.iterable", "esnext"],
    "allowJs": true,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "noFallthroughCasesInSwitch": true,
    "module": "esnext",
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true,
    "jsx": "react-jsx"
  },
  "include": ["src"]
}

Set up rollup

npm i rollup

npm i @rollup/plugin-node-resolve @rollup/plugin-commonjs @rollup/plugin-typescript rollup-plugin-peer-deps-external @rollup/plugin-terser rollup-plugin-dts --save-dev

Update package.json

{
    ...
    "main": "dist/index.js",
    "module": "dist/index.mjs",
    "types": "dist/index.d.ts",
    ...
}

Create roll up config rollup.config.js in root folder

//rollup.config.js

import resolve from "@rollup/plugin-node-resolve";
import commonjs from "@rollup/plugin-commonjs";
import typescript from "@rollup/plugin-typescript";
import dts from "rollup-plugin-dts";
import terser from "@rollup/plugin-terser";
import peerDepsExternal from "rollup-plugin-peer-deps-external";

const packageJson = require("./package.json");

export default [
  {
    input: "src/index.ts",
    output: [
      {
        file: packageJson.main,
        format: "cjs",
        sourcemap: true,
      },
      {
        file: packageJson.module,
        format: "esm",
        sourcemap: true,
      },
    ],
    plugins: [peerDepsExternal(), resolve(), commonjs(), typescript({ tsconfig: "./tsconfig.json" }), terser()],
    external: ["react", "react-dom"],
  },
  {
    input: "src/index.ts",
    output: [{ file: packageJson.types }],
    plugins: [dts.default()],
  },
];

Add build script in package.json

{
   ...
   "scripts": {
     "rollup": "rollup -c --bundleConfigAsCjs",
     ...
   }
 }