tsconfig.json

{
    "compilerOptions": {
        "outDir": "./build",
        "allowJs": false,
        "module": "commonjs",
        "target": "es5",
        "lib": ["es2018", "es2015", "es6", "es2015.promise", "dom"],
        "strict": false,
        "declaration": true,
        "moduleResolution": "node",
        "allowSyntheticDefaultImports": true,
        "types": ["node", "jest"],
        "sourceMap": true,
        "resolveJsonModule": true,
        "downlevelIteration": true,
        "skipLibCheck": true
    },
    "include": ["src/**/*"],
    "exclude": ["./node_modules", "./build", "src/__tests__/**/*"]
}