tsconfig.json

{
  "compilerOptions": {
    "module": "commonjs",
    "target": "es5",
    "lib": ["es2015", "es2016", "es2017", "dom"],
    "outDir": "build",
    "typeRoots": [
      "node_modules/@types"
    ],
    "types": [
      "node",
      "jest"
    ],
    "declaration": true,
    "downlevelIteration": true,
    "emitDecoratorMetadata": true,
    "esModuleInterop": true,
    "experimentalDecorators": true,
    "forceConsistentCasingInFileNames": true,
    "inlineSourceMap": true,
    "noFallthroughCasesInSwitch": true,
    "noImplicitAny": false,
    "noImplicitReturns": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "resolveJsonModule": true,
    "strict": true,
    "useUnknownInCatchVariables": false
  },
  "include": [
    "scripts",
    "src",
    "__tests__"
  ],
  "compileOnSave": true
}