tsconfig.json

{
  "compilerOptions": {
    "module": "commonjs",
    "moduleResolution": "node",
    "target": "es6",
    /* Strict Type-Checking Options */
    "strict": true,
    /* Additional Checks */
    /* next line commented out because we need unused vars for type tests */
    // "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,
    "lib": ["es2017"]
  },
  "include": [
        "types/**/*"
    ]
}