Gsd-skill-creator typescript-patterns

TypeScript best practices and patterns. Use when writing TypeScript, fixing type errors, or working with generics.

install

source · Clone the upstream repo

git clone https://github.com/Tibsfox/gsd-skill-creator

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/Tibsfox/gsd-skill-creator "$T" && mkdir -p ~/.claude/skills && cp -r "$T/examples/skills/dev/typescript-patterns" ~/.claude/skills/tibsfox-gsd-skill-creator-typescript-patterns && rm -rf "$T"

manifest: examples/skills/dev/typescript-patterns/SKILL.md

source content

TypeScript Patterns

Type vs Interface

Use Case	Prefer
Object shape	interface
Union types	type
Extending shapes	interface
Intersection	type
Tuple/primitives	type

Key Patterns

Discriminated Unions — model state with tagged types:

type Result<T> = { ok: true; value: T } | { ok: false; error: Error };

Type Guards — narrow at runtime:

function isUser(obj: unknown): obj is User {
  return typeof obj === 'object' && obj !== null && 'id' in obj;
}

Generic Constraints:

function getProperty<T, K extends keyof T>(obj: T, key: K): T[K] { return obj[key]; }

Utility Types

Type	Purpose
Partial<T>	All optional
Required<T>	All required
Pick<T,K>	Select properties
Omit<T,K>	Remove properties
Record<K,V>	Key-value map
ReturnType<T>	Function return type

Avoid

```
any
```
— use
```
unknown
```
and narrow
Type assertions (
```
as
```
) — use type guards
```
!
```
operator — handle null properly
Missing return types on complex functions