tsconfig.build.json

{
  "compilerOptions": {
    "module": "ESNext",
    // use Node's module resolution algorithm, instead of the legacy TS one
    "moduleResolution": "node",
    "declaration": true,
    "declarationMap": true,
    "emitDeclarationOnly": true,
    "experimentalDecorators": true,
    "allowJs": true,
    "isolatedModules": true,
    "jsx": "react",
    "target": "ES6",
    // interop between ESM and CJS. Recommended by TS
    "esModuleInterop": true,
    // significant perf increase by skipping checking .d.ts files, particularly those in node_modules. Recommended by TS
    "skipLibCheck": true,
    // error out if import and file system have a casing mismatch. Recommended by TS
    "forceConsistentCasingInFileNames": true,

    // turn these settings on when we start to migrate the codebase
    "checkJs": false,
    "noImplicitAny": true,
    "strict": true,
    // linter checks for common issues
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,
    // noUnused* overlap with @typescript-eslint/no-unused-vars, can disable if duplicative
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    // ES2019 is needed so TS recognizes new features like Array.flat
    "lib": ["ES2019", "DOM", "DOM.Iterable"]
  },
  "exclude": ["node_modules"]
}