# Fabiensalles Claude Marketplace TS Code Conventions

> Code Conventions — TypeScript

- Skill: `tomevault-io/fabiensalles-claude-marketplace-ts-code-conventions` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/fabiensalles-claude-marketplace-ts-code-conventions`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/fabiensalles-claude-marketplace-ts-code-conventions/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/fabiensalles-claude-marketplace-ts-code-conventions

---


# Code Conventions — TypeScript

> The **cross-language rules** (control-structure spacing, early return, continue vs if/else, parameter ordering, flatten null checks) are defined in `craft:code-style-principles`. This skill keeps TS-specific syntax (optional chaining, nullish coalescing, template literals) and pointers to the project's `references/code-examples.md`.

> See also: `ts-conventions` for typing rules (strict mode, branded types).

These conventions go beyond standard linting rules (eslint/prettier).

> **For complete worked examples** (control-structure spacing, early return, continue patterns, parameter ordering), read `references/code-examples.md`.

## TS-specific: Optional Chaining and Nullish Coalescing

Use `?.` to flatten nested null checks, and `??` for "default if null/undefined".

```typescript
// Optional chaining
if (customer.personalInfo?.usPerson === true) {
  types.push('us_person');
}

// Nullish coalescing
const name = user.displayName ?? 'Anonymous';
```

## TS-specific: No Implicit Truthy / Falsy

Use **explicit comparisons** instead of relying on JavaScript's truthy/falsy coercion.

```typescript
// ✅ Explicit checks
if (array.length > 0) { /* ... */ }
if (string === '') { /* ... */ }
if (value !== null && value !== undefined) { /* ... */ }

// ✅ Exception — booleans can be checked directly
if (isValid) { /* ... */ }
```

## TS-specific: Template Literals Over Concatenation

```typescript
const message = `Hello ${user.name}, you have ${count} items`;
```

## Quick Reference (TS-specific only)

> For the cross-language quick reference (early return, continue, blank lines, parameter ordering), see `craft:code-style-principles`.

| Rule | Example |
|------|---------|
| Optional chaining | `a?.b?.c` instead of nested `if` |
| Nullish coalescing | `value ?? 'default'` |
| Explicit checks | `array.length > 0` (not `array.length`) |
| Template literals | `` `Hello ${name}` `` (not `'Hello ' + name`) |

---
> Source: [FabienSalles/claude-marketplace](https://github.com/FabienSalles/claude-marketplace) — distributed by [TomeVault](https://tomevault.io).
<!-- tomevault:4.0:skill_md:2026-06-01 -->