tsconfig.json

{
  "compilerOptions": {
    "module": "commonjs",
    "target": "es6",
    "moduleResolution": "node",
    "outDir": "build",
    "sourceMap": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "esModuleInterop": true,
    "noUnusedLocals": true /* Report errors on unused locals. */,
    "noUnusedParameters": true /* Report errors on unused parameters. */,
    "noFallthroughCasesInSwitch": true, /* Report errors for fallthrough cases in switch statement. */
    "strict": true, /* Enable all strict type-checking options. */
    "noImplicitAny": true, /* Raise error on expressions and declarations with an implied 'any' type. */
    "strictNullChecks": false,
    "strictFunctionTypes": true, /* Enable strict checking of function types. */
    "strictBindCallApply": true, /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
    "noImplicitThis": true, /* Raise error on 'this' expressions with an implied 'any' type. */
    "alwaysStrict": true /* Parse in strict mode and emit "use strict" for each source file. */
  },
  "exclude": ["build", "node_modules"]
}