typescript-fix

Use the typescript-expert skill. Preserve the user's scope and the project's runtime behavior.

1. Discover the Actual Checker

Inspect:

• package.json, workspaces, and the lockfile to identify the package manager;
• all relevant tsconfig*.json files and their extends chains;
• the installed TypeScript version;
• existing typecheck/build scripts and framework checkers such as vue-tsc, svelte-check, Angular, Astro, or MDX tooling;
• the current working-tree diff so unrelated user changes are preserved.

If TypeScript 7 is installed or proposed, check whether the toolchain imports the Compiler API or requires the TypeScript 6 compatibility line. Do not upgrade dependencies unless the user requested an upgrade.

2. Establish the Baseline

Run the repository's existing type-check script. If none exists, invoke the local compiler through the detected package manager; do not use a command that can silently download a different TypeScript version.

Examples:

npm exec -- tsc --noEmit
pnpm exec tsc --noEmit
yarn exec tsc --noEmit
bun run tsc --noEmit

Do not force --noEmit when the project validates declarations, uses project references/build mode, or relies on emit. Capture the command, compiler/checker version, exit code, and complete diagnostics.

If the baseline is clean, report it and stop. If the command cannot run for an environmental reason, report BLOCKED rather than editing from guessed diagnostics.

3. Find Root Causes

Group related diagnostics, but fix dependency order rather than raw error count:

1. wrong project/config or file selection;
2. missing or incompatible declarations and module resolution;
3. incorrect shared domain/API types;
4. implementation narrowing, generics, and nullability;
5. isolated downstream errors.

For each group, inspect the source, the expected runtime behavior, and the declaring dependency. A single wrong export or widened type can cause many secondary diagnostics.

4. Apply Minimal Type-safe Fixes