tsconfig.json

{
  "compilerOptions": {
    /* Basic Options */
    "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
    // Using es6 module for tree-shaking tslib in UMD build (https://github.com/microsoft/TypeScript/issues/16999)
    "module": "es6",                          /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
    "jsx": "react",                           /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
    "declaration": false,                     /* Generates corresponding '.d.ts' file. */
    "sourceMap": false,                       /* Generates corresponding '.map' file. */
    "outDir": "./esm",                         /* Redirect output structure to the directory. */
    "resolveJsonModule": true,                /* Include modules imported with .json extension. */
    "importHelpers": true,                    /* Import emit helpers from 'tslib'. */

    /* Strict Type-Checking Options */
    "strict": true,                           /* Enable all strict type-checking options. */

    /* Module Resolution Options */
    "moduleResolution": "node",               /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
    "esModuleInterop": true                   /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
  },
  "include": [
    "src"
  ],
  "exclude": [
    "./src/__tests__",
    "umd.ts",
  ]
}