tsconfig.base.json

{
  // https://www.npmjs.com/package/@tsconfig/node14
  "extends": "@tsconfig/node14/tsconfig.json",

  "compilerOptions": {
    "moduleResolution": "node", // modern
    "resolveJsonModule": true, // allow importing JSON filees
    "jsx": "preserve", // don't mangle JSX in intermediate phase
    "experimentalDecorators": true, // enable decorators
    "emitDecoratorMetadata": true, // for runtime use of decorators (typeORM)
    // "baseUrl": "packages", // allow absolute path imports for all project packages
    "strictPropertyInitialization": false, // for TypeORM

    "noImplicitAny": true, // strictness
    "noImplicitThis": true, // strictness
    // "noUnusedLocals": true /* Report errors on unused locals. */,
    // "noUnusedParameters": true /* Report errors on unused parameters. */,
    "noImplicitReturns": true /* Report error when not all code paths in function return a value. */,
    "noFallthroughCasesInSwitch": true /* Report errors for fallthrough cases in switch statement. */
  }
}