rule-typescript

name	rule-typescript
description	Middle Earth TypeScript baseline guidelines (compiler, modules, best practices)

Rule typescript

Apply this rule whenever work touches:

• **/*.ts
• **/*.tsx

TypeScript (Middle Earth)

Compiler and language

• Respect tsconfig.base.json: strict true, verbatimModuleSyntax, noUnusedLocals/Parameters.
• Use the provided path aliases (@middle-earth/libs/publishable/*); do not import via relative ../../...
• No any or unsafe casts; favor precise types and narrowing.

Modules and barrels

• Import from library barrels (src/index.ts). Avoid deep imports into internal files.
• Keep public types exported from the barrel.

Functions and variables

• Prefer explicit function return types for exported functions and public APIs.
• Meaningful identifiers; no 1-2 letter names; avoid abbreviations unless industry-standard.
• Use early returns and narrow unions with type guards.
• Organize constants, helpers, and types by file: *.constants.ts, *.helpers.ts, *.types.ts.

Error handling

• Use Result-like patterns or typed errors. Do not swallow errors; add context.
• Prefer type-fest utility types where possible.

Lint integration

• Follow root ESLint config (Airbnb base/typescript, SonarJS, Unicorn, Security, Promise, Perfectionist, Prettier).
• Avoid default exports unless required by a framework (e.g., Next.js pages/layouts).