tsconfig.json

{
  "compilerOptions": {
    "jsx": "react-jsx",
    "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
    "module": "commonjs",                                /* Specify what module code is generated. */
    "lib": [
      "es2017",
      "es7",
      "es6",
      "dom"
    ],
    "rootDir": "src",
    "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables `allowSyntheticDefaultImports` for type compatibility. */
    "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */
    "strict": true,                                      /* Enable all strict type-checking options. */
    "skipLibCheck": true,
    "declaration": true, /* Generates corresponding '.d.ts' file. */
    "emitDeclarationOnly": false,
    "declarationMap": true, /* Generates a sourcemap for each corresponding '.d.ts' file. */
    "outDir": "build",
    "typeRoots": ["./node_modules/@types", "./src/types"],
  },
  "include": ["./src/index.ts", "./src/components/FastMasonry/FastMasonry.tsx", "./src/**/*"],
}