typescript

name	typescript
description	Apply TypeScript performance and safety rules. Use for tsc speed, tsconfig, type errors, async patterns, module organization, import hygiene, type definitions, memory issues, or .ts/.tsx/.d.ts work. Not for TypeScript basics or framework-specific testing.

TypeScript Best Practices

Use this skill as a compact router to the TypeScript rule pack. A TypeScript rule is a narrow, evidence-backed coding guideline whose purpose is to improve compile speed, runtime behavior, type safety, or maintainability for TypeScript projects.

The full compiled document is AGENTS.md. Individual detailed rules live under references/.

Rules

1. Start with the highest-impact category that matches the work.
2. Read the specific reference file before applying a non-obvious rule.
3. Prefer project conventions when a rule conflicts with established local architecture.
4. Verify with the project typecheck, test, or build command after edits.

Categories

Priority	Category	Use for	Prefix
1	Type system performance	slow type checking, complex types, exported APIs	type-
2	Compiler configuration	tsconfig, project references, included files	tscfg-
3	Async patterns	Promise concurrency, async wrappers, return types	async-
4	Module organization	imports, barrels, dynamic imports, @types scope	module-
5	Type safety	unknown, guards, exhaustive checks, nullability	safety-
6	Memory management	timers, listeners, closures, global caches	mem-
7	Runtime optimization	hot loops, lookups, object spread, string methods	runtime-
8	Advanced patterns	branded types, satisfies, template literal types	advanced-

Quick Map

Type system:

• type-interfaces-over-intersections
• type-avoid-large-unions
• type-extract-conditional-types
• type-limit-recursion-depth
• type-explicit-return-types
• type-avoid-deep-generics
• type-simplify-mapped-types

Compiler:

• tscfg-enable-incremental
• tscfg-skip-lib-check
• tscfg-isolate-modules
• tscfg-project-references
• tscfg-exclude-properly
• tscfg-strict-function-types

Async and modules:

• async-parallel-promises
• async-defer-await
• async-avoid-loop-await
• async-explicit-return-types
• async-avoid-unnecessary-async
• module-avoid-barrel-imports
• module-avoid-circular-dependencies
• module-use-type-imports
• module-dynamic-imports
• module-control-types-inclusion

Safety, memory, runtime, advanced:

• safety-prefer-unknown-over-any
• safety-use-type-guards
• safety-exhaustive-checks
• safety-strict-null-checks
• safety-const-assertions
• safety-assertion-functions
• mem-use-weakmap-for-metadata
• mem-avoid-closure-leaks
• mem-cleanup-event-listeners
• mem-avoid-global-state
• mem-clear-timers
• runtime-use-set-for-lookups
• runtime-cache-property-access
• runtime-avoid-object-spread-in-loops
• runtime-use-for-of-for-iteration
• runtime-prefer-array-methods
• runtime-use-string-methods
• advanced-branded-types
• advanced-template-literal-types
• advanced-satisfies-operator

Use

Open the specific reference file for detailed examples, apply the smallest relevant rule, and verify with the local TypeScript check. The skill is complete only when the chosen rule, changed files, and verification command are reported.