tsconfig.json

{
  "compilerOptions": {
    // Compilation target and standard library
    "target": "ES2022",
    "lib": ["ES2022"],

    // Module system.
    // "node16" / "node16": the modern Node-compatible pair introduced in TypeScript 4.7.
    // Because package.json has no "type": "module" field, every .ts file is treated as
    // CommonJS by Node16 semantics — emitted output is identical to "commonjs", but with
    // package.json exports/imports field support and no deprecated-resolution warning.
    // allowSyntheticDefaultImports is implied by esModuleInterop; not listed separately.
    "module": "node16",
    "moduleResolution": "node16",
    "esModuleInterop": true,

    // Output
    "outDir": "./dist",
    "rootDir": "./src",
    "declaration": true,
    "declarationMap": true,
    "sourceMap": true,
    "removeComments": true,
    "resolveJsonModule": true,

    // Type safety — all strict checks active
    "strict": true,
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,
    // noUnusedLocals / noUnusedParameters are off intentionally: many service files use
    // broad `any` types and partial implementations; enabling these would produce
    // non-actionable warnings during incremental development.
    "noUnusedLocals": false,
    "noUnusedParameters": false,

    // skipLibCheck: false — external type definitions are accurate and free of errors.
    // Setting this to true would mask real type errors in project code that originate
    // from mismatches with library types (e.g. jsonwebtoken SignOptions, Prisma input types).
    // Only change to true if a third-party package ships broken .d.ts files that block CI.
    "skipLibCheck": false,

    "forceConsistentCasingInFileNames": true,

    // isolatedModules: required by ts-jest when using module: "node16", and a best practice
    // for modern TypeScript — each file must be a standalone module (no global scripts).
    "isolatedModules": true,

    // Decorators — required by libraries that use reflect-metadata (e.g. class-validator)
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true

    // baseUrl and paths removed: no source file uses the @ aliases.
    // Jest resolves them independently via moduleNameMapper in jest.config.js.
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", "dist", "**/*.test.ts", "**/*.spec.ts"]
}