tsconfig.base.json

{
  "extends": "@tsconfig/strictest/tsconfig.json",
  "compilerOptions": {
    /* ES2025 language level. SWC does no downleveling (target: esnext), so
       whatever is written here is what ships. The runtime floor is Node 22.12
       (engines.node) — `lib` runs slightly ahead of it, so check availability
       before reaching for a brand-new built-in. CI's lowest leg is the floor. */
    "target": "ES2025",
    "lib": ["ES2025", "DOM", "DOM.Iterable"],

    /* TS6 requires an explicit, non-legacy module/resolution pair.
       `preserve` + `bundler` matches the ESM-with-.js-specifiers sources that
       SWC emits as-is; the packages are ESM only. */
    "module": "Preserve",
    "moduleResolution": "Bundler",
    "verbatimModuleSyntax": true,
    "isolatedModules": true,
    "esModuleInterop": true,
    "resolveJsonModule": true,

    "jsx": "react-jsx",
    "declaration": true,
    "declarationMap": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "noUncheckedSideEffectImports": true,
    "incremental": true
  }
}