javascript

A set of JavaScript and TypeScript coding rules for XM Cloud projects, including names and file layouts for React components, variables, types, and utilities.

In plain words
What is it for?
Use it when naming JavaScript or TypeScript code, creating React components, choosing file names, or defining props and other types.
Why use it?
It keeps code consistent and makes project files easier to find and understand.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/sitecore/xmcloud-starter-js/javascript
Clone the repo
git clone --depth 1 https://github.com/Sitecore/xmcloud-starter-js

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 1,420 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.01420
Opus 5 $0.00000 $0.00710
Sonnet 5 $0.00000 $0.00284
Haiku 4.5 $0.00000 $0.00142

Measured yesterday against content hash 31c812774e45, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

javascript scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/javascript.mdc · 171 lines

How it starts

The opening of the file, as written. The whole thing — 171 lines — stays where its author put it; the contents beside it link to each section on GitHub.

JavaScript/TypeScript Rules

Naming Conventions

Variables and Functions:

  • Use camelCase: handleClick(), isActive, prefersReducedMotion
  • Boolean variables: prefix with is, has, can, should
  • Event handlers: prefix with handle or on: handleClick, handleKeyDown
  • State variables: descriptive names like activeIndex, isExpanding

Components (React):

  • Use PascalCase: ArticleHeader, ProductListing, VerticalImageAccordion
  • Main component files: Hero.tsx, ProductListing.tsx
  • Component directories: kebab-case like article-header/, product-listing/

Constants and Variables:

  • Use UPPER_SNAKE_CASE: USER_ZIPCODE, DEFAULT_TIMEOUT
  • Environment variables: SITECORE_EDGE_CONTEXT_ID, NEXT_PUBLIC_DEFAULT_SITE_NAME
  • Dictionary keys: dictionaryKeys.HERO_SubmitCTALabel

File Naming Patterns:

  • Utilities: NoDataFallback.tsx, date-utils.ts
  • Main components: ComponentName.tsx

Types and Interfaces:

  • Component props: HeroProps, ArticleHeaderProps, ProductListingProps
  • Field interfaces: ArticleHeaderFields, HeroFields
  • Parameter interfaces: ArticleHeaderParams, VerticalImageAccordionParams
  • Use { [key: string]: any; // eslint-disable-line } for flexible params

Code Layout and Organization

Directory Structure:

src/
  components/          # React components organized by feature
    hero/             # Component directories with variants
      Hero.tsx        # Main component file with props and variants
    article-header/   # Component with complex structure
    product-listing/  # Multi-variant component
    ui/              # Shadcn/ui components
    image/           # Reusable image wrapper
    button-component/ # Button variations
  lib/                # Configuration and utilities
    component-props/  # Shared component props
    constants.ts      # Application constants
    utils.ts          # Common utilities
  utils/              # Helper functions and utilities
    NoDataFallback.tsx # Standard fallback component
    date-utils.ts     # Date formatting utilities
  hooks/              # Custom React hooks
  variables/          # Constants and dictionary keys
  styles/             # Styling files (global CSS)

Read the full file on GitHub · 171 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 171 lines · 0 tokens per session scan A 31c812774e45

Subscribe to this mod's changes

javascript is a cursor rule published in the GitHub repository Sitecore/xmcloud-starter-js (29 stars, last pushed 7d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 1,420 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.