tsconfig.json

{
  "compilerOptions": {
    "allowJs": false,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "noImplicitAny": false,
    "noUnusedLocals": true,
    "noImplicitReturns": true,
    "noLib": false,
    "removeComments": true,
    "declaration": true,
    "forceConsistentCasingInFileNames": true,
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "allowSyntheticDefaultImports": true,
    "esModuleInterop": true,
    "lib": ["es2015", "es2017", "dom", "esnext.asynciterable"],
    "target": "es5",
    "module": "commonjs",
    "sourceMap": true,
    "typeRoots": [
      "./node_modules/@types",
      "./node_modules/@counterfactual/typescript-typings/types"
    ],
    // @types/mocha has a duplicate conflict, this is the suggested temp fix.
    "skipLibCheck": true,
    "strict": true
  }
}