lang-typescript_skill

Overview

This skill provides targeted TypeScript 5.9+ guidance and code patterns for SolidJS, TanStack Start, and Valibot-based validation. It helps write, debug, and configure .ts/.tsx files, create Solid components, wire TanStack routes/server functions, and craft type-safe validation schemas. Use it to enforce strict typing, reusable patterns, and predictable builds in modern TypeScript apps.

How this skill works

The skill inspects file extensions (.ts, .tsx, .mts, .cts), tsconfig and lint configs, and project scripts (justfile, package scripts) to align changes with project conventions. It suggests code that avoids forbidden patterns (no any, no enums, no default exports, no non-null assertions, no @ts-ignore) and uses SolidJS primitives, TanStack Start routing/server-function patterns, and Valibot schemas. It recommends running tsc --noEmit, bun/vitest tests, and lint checks after edits.

When to use it

• When asked to write or refactor TypeScript (.ts/.tsx/.mts/.cts) files
• When creating or debugging SolidJS components or patterns (signals, stores, resources)
• When configuring TanStack Start file-based routes, loaders, or server functions
• When validating or generating Valibot schemas and type-safe parsers
• When running type checks, linting, or test commands in a TypeScript project

Best practices

• Prefer named exports; avoid default exports for consistency and tree-shaking
• Never use any; use unknown or explicit types and narrow with type guards
• Avoid enum and non-null assertions; use union types and optional chaining/nullish coalescing
• Use tsconfig.json and eslint config to match project conventions; run tsc --noEmit after changes
• Match file extension to content: .tsx for JSX, .ts for plain logic; ensure created files follow project layout

Example use cases

• Create a SolidJS component using createSignal, createMemo, and <For> with strict props types
• Add a TanStack Start route with a server function and useLoaderData type-safe loader
• Write Valibot schema for an API payload and derive TypeScript types without any
• Refactor a module to remove enums and any, replace with union types and type guards
• Diagnose type errors by inspecting tsconfig, running tsc --noEmit, and updating types to satisfy the compiler