@systemfsoftware/arethetypeswrong-core

The API behind arethetypeswrong.github.io.

⚠️ This package is in major version v0 and the API may change significantly in patch and minor releases. Use at your own risk. Documentation will not be provided at least until the package reaches version v1.

TypeScript version pin

The runtime dependency typescript runs on the 6.x JS bridge (catalog:attw, ^6.0.3) — the last TypeScript line with the full JS compiler API — while the rest of the monorepo runs typescript@7 (native Go compiler, catalog:).

typescript@7 exports no JS compiler API: the package main entry is ./lib/version.cjs (version strings only), and the unstable/* exports are an LSP-style snapshot client (API/Snapshot/Project/Program/Checker) with no createProgram, no resolveModuleName, no CompilerHost, no module-resolution caches, and no resolution traces. The analysis engine in src/internal/multiCompilerHost.ts (and getEntrypointInfo.ts) is built on exactly those internals, several of which are only reachable via ts-expose-internals (which tops out at 5.6.3 — its type augmentation still typechecks cleanly against 6.0.3). A tsgo-API rewrite would require reimplementing TypeScript's module resolution and would change analysis fidelity — the checks this package produces are resolution-behavior reports, so fidelity is the product.

typescript@6 (the bridge release) keeps the full compiler API, so this package is as close to TypeScript 7 as its architecture allows. Two snapshot fixtures ([email protected], [email protected]) embed the compiler version in resolution traces and were regenerated when moving 5.9.3 → 6.0.3.

The original arethetypeswrong pins [email protected] for the same fidelity reason.

Dependabot is configured to never propose a typescript major bump for this repo (see .github/dependabot.yml); majors are manual, deliberate migrations. The durable record of this decision lives in docs/solutions/tooling-decisions/arethetypeswrong-core-requires-js-typescript-api.md.