Code Quality

Linting, documentation, and general code quality standards.

Lint Commands

bash

# Pre-commit (fast, only staged files)
yarn lint:staged
yarn tsc:staged

# CI only (full project check)
yarn lint        # Comprehensive: TypeScript, ESLint, folder structure, i18n
yarn lint:only   # Quick: oxlint only
yarn tsc:only    # Full type check

Note: yarn lint is for CI only. For pre-commit, always use yarn lint:staged.

Pre-Commit Workflow

For fast pre-commit validation:

bash

# Lint only modified files (recommended)
yarn lint:staged

# Or with type check
yarn lint:staged && yarn tsc:staged

Common Lint Fixes

typescript

// Unused variable - prefix with underscore
const { used, unused } = obj;     // ❌ Error: 'unused' is defined but never used
const { used, unused: _unused } = obj;  // ✅ OK

// Unused parameter - prefix with underscore
function foo(used: string, unused: number) {}     // ❌ Error
function foo(used: string, _unused: number) {}    // ✅ OK

// Floating promise - add void or await
someAsyncFunction();        // ❌ Error: Promises must be awaited
void someAsyncFunction();   // ✅ OK (fire-and-forget)
await someAsyncFunction();  // ✅ OK (wait for result)

Language Requirements

All comments must be written in English:

typescript

// ✅ GOOD: English comment
// Calculate the total balance including pending transactions

// ❌ BAD: Chinese comment
// 计算总余额，包括待处理的交易

// ✅ GOOD: JSDoc in English
/**
 * Fetches user balance from the blockchain.
 * @param address - The wallet address to query
 * @returns The balance in native token units
 */
async function fetchBalance(address: string): Promise<bigint> {
  // ...
}

When to Comment

typescript

// ✅ GOOD: Explain non-obvious logic
// Use 1.5x gas limit to account for estimation variance on this chain
const gasLimit = estimatedGas * 1.5n;

// ✅ GOOD: Explain business logic
// Premium users get 50% discount on transaction fees
const fee = isPremium ? baseFee * 0.5 : baseFee;

// ❌ BAD: Obvious comment
// Set the value to 5
const value = 5;

Development Principles

Single Responsibility

Each function should perform a single, atomic task:

typescript

// ✅ GOOD: Single responsibility
async function fetchUserBalance(userId: string): Promise<Balance> {
  const user = await getUser(userId);
  return await getBalanceForAddress(user.address);
}

// ❌ BAD: Multiple responsibilities
async function fetchUserBalanceAndUpdateUI(userId: string) {
  const user = await getUser(userId);
  const balance = await getBalanceForAddress(user.address);
  setBalanceState(balance);
  showNotification('Balance updated');
  logAnalytics('balance_fetched');
}

Avoid Over-Abstraction

Don't create helpers for one-time operations:

typescript

// ❌ BAD: Over-abstracted
const createUserFetcher = (config: Config) => {
  return (userId: string) => {
    return fetchWithConfig(config, `/users/${userId}`);
  };
};
const fetchUser = createUserFetcher(defaultConfig);
const user = await fetchUser(userId);

// ✅ GOOD: Simple and direct
const user = await fetch(`/api/users/${userId}`).then(r => r.json());

Detailed Guides

Code Quality Standards

See code-quality.md for comprehensive guidelines:

•Linting commands and pre-commit workflow
•Comment and documentation standards
•Language requirements (English only)
•Single responsibility principle
•Avoiding over-abstraction
•Consistent naming conventions
•Code quality checklist

Fixing Lint Warnings

See fix-lint.md for complete lint fix workflow:

•Analyzing lint warnings
•Categorizing lint errors
•Common fix patterns by category
•Spellcheck fixes
•Unused variable/parameter handling
•Automated fix strategies
•Testing after fixes

Spellcheck

If a technical term triggers spellcheck errors:

bash

# Check if word exists
grep -i "yourword" development/spellCheckerSkipWords.txt

# Add if not present (ask team lead first)
echo "yourword" >> development/spellCheckerSkipWords.txt

Checklist

Pre-commit

• yarn lint:staged passes
• yarn tsc:staged passes

Code Quality

• All comments are in English
• No commented-out code committed
• Functions have single responsibility
• No unnecessary abstractions
• Consistent naming conventions

Related Skills

•/sentry-analysis - Sentry error analysis and fixes
•/coding-patterns - General coding patterns