tsconfig.json

{
  "compilerOptions": {
    "allowArbitraryExtensions":true,
    "target": "es2017",
    "lib": [
       "es2018"
    ],
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "strictFunctionTypes": true,
    "module": "CommonJS",
    "allowImportingTsExtensions":true,
    "esModuleInterop":true,
    "noImplicitAny": true,
    "alwaysStrict":true,
    "noImplicitReturns":true,
    "strictNullChecks"             : true,
    "noUncheckedIndexedAccess"     : true,
    "noErrorTruncation"            : true,
    "strictPropertyInitialization": true,
    // Generate d.ts files
    "declaration": true,
    // This compiler run should
    // only output d.ts files
    "emitDeclarationOnly": true,
    // Types should go into this directory.
    // Removing this would place the .d.ts files
    // next to the .js files
    "outDir": "dist/types",
    // go to js file when using IDE functions like
    // "Go to Definition" in VSCode
    "declarationMap": true,
  },
  "exclude": ["node_modules", "dist","tmp"]
}