@anacare/tsconfig — Shared TypeScript presets

Status: in use from day 0. This is the only packages/* that has real content today; everything else is a placeholder until Round 8.

The single source of truth for TypeScript compiler configuration in the monorepo. Every tsconfig.json in apps/* and packages/* (other than @anacare/tsconfig itself) extends one of the presets here.

Presets

| Preset | Use in | Key differences from base | |---|---|---| | base.json | Not used directly — the canonical foundation that every other preset extends. | strict: true + the seven strict-extra flags. Bundler module resolution. ESM-friendly. | | library.json | packages/* (other than this one) | Emits dist/, declarations, source maps. ESNext module. | | nextjs.json | apps/web-admin, apps/client-dashboard | DOM lib. JSX preserve (Next compiles). noEmit: true. Next plugin. | | expo.json | apps/mobile | React Native types. JSX react-jsx. noEmit: true. | | nestjs.json | apps/api | CommonJS module. Node moduleResolution. Decorator metadata enabled. verbatimModuleSyntax: false (decorators need elision). |

How to extend

In a consumer tsconfig.json:

{
  "extends": "@anacare/tsconfig/library",
  "compilerOptions": {
    // Only override what genuinely needs to be different.
    "paths": {
      "@/*": ["./src/*"]
    }
  },
  "include": ["src"]
}

The extends path uses the package's exports field (package.json). TypeScript 5+ resolves these natively.

Editing rules

• Changes to base.json ripple to every project. Open an ADR if the change tightens or loosens a strict flag. Loosening a flag is rarely the right answer; usually we add per-app // @ts-expect-error with a comment, or fix the code.
• Per-app overrides belong in the app's own tsconfig.json, not here.
• Never remove a flag from base.json without an ADR. The flags catch real bugs in clinical and financial code paths.

Why not just put presets in the repo root?

A package gives us:

• Versioning via Changesets — a breaking change to base.json is a major bump that consumers explicitly accept.
• Clean import path (@anacare/tsconfig/library) vs fragile relative paths (../../../tsconfig.base.json).
• A natural place to add adjacent helpers (e.g., @anacare/tsconfig/types with shared ambient declarations) without sprawling the root.