2nd/10_Wiki/Topics/AI_and_ML/ESLint-Static-Analysis.md

---
id: wiki-2026-0508-eslint-static-analysis
title: ESLint Static Analysis
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [ESLint, JS linter, static analysis, custom rule, AST, biome, oxlint]
duplicate_of: none
source_trust_level: A
confidence_score: 1.0
verification_status: applied
tags: [software-engineering, static-analysis, eslint, javascript, typescript, ast, lint]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: JavaScript / TypeScript
  framework: ESLint 9 / Biome / oxlint
---

# ESLint Static Analysis

## 매 한 줄
> **"매 JS / TS 의 AST-based static analysis"**. 매 syntax + style + bug pattern 의 catch. 매 modern (2024+): 매 flat config + 매 typescript-eslint + 매 fast alternative (Biome, oxlint). 매 custom rule = 매 enforcement.

## 매 핵심

### 매 mechanism
- 매 source → AST (espree / @typescript-eslint/parser).
- 매 visitor pattern 의 rule traverse.
- 매 violation 의 fix suggestion (autofix).

### 매 modern (2024+)
- **Flat config** (eslint.config.js): 매 .eslintrc legacy out.
- **typescript-eslint v8**: 매 type-aware lint.
- **Biome**: 매 Rust-based 25x faster.
- **oxlint**: 매 even faster (50-100x).
- **Stylistic plugin**: 매 ESLint core 의 style rule 의 spin off.

### 매 응용
1. **Coding standard**: 매 team consistency.
2. **Bug prevention**: 매 no-undef, no-shadow.
3. **Performance**: 매 react-hooks rules.
4. **Security**: 매 eslint-plugin-security.
5. **Custom**: 매 team-specific anti-pattern.

### 매 LLM era
- **AI-assisted rule**: 매 LLM 의 rule generate.
- **Hybrid**: 매 ESLint + Corgea / Snyk.
- **Auto-fix**: 매 LLM 의 complex pattern.

## 💻 패턴

### Flat config
```javascript
// eslint.config.js
import js from '@eslint/js';
import tseslint from 'typescript-eslint';
import stylistic from '@stylistic/eslint-plugin';

export default tseslint.config(
  js.configs.recommended,
  ...tseslint.configs.recommendedTypeChecked,
  {
    languageOptions: {
      parserOptions: { project: './tsconfig.json' },
    },
    plugins: { '@stylistic': stylistic },
    rules: {
      '@stylistic/semi': ['error', 'always'],
      '@typescript-eslint/no-floating-promises': 'error',
      'no-console': ['warn', { allow: ['warn', 'error'] }],
    },
  },
);
```

### Custom rule (no console.log)
```javascript
// .eslint-rules/no-console-log.js
export default {
  meta: {
    type: 'problem',
    docs: { description: 'Disallow console.log (use logger)' },
    fixable: 'code',
    schema: [],
  },
  create(context) {
    return {
      'CallExpression[callee.object.name="console"][callee.property.name="log"]'(node) {
        context.report({
          node,
          message: 'Use logger.info instead of console.log',
          fix(fixer) {
            return fixer.replaceText(node.callee, 'logger.info');
          },
        });
      },
    };
  },
};
```

### Custom — forbid hardcoded URL
```javascript
export default {
  meta: { type: 'problem' },
  create(context) {
    return {
      Literal(node) {
        if (typeof node.value === 'string' && /^https:\/\/internal\./.test(node.value)) {
          context.report({ node, message: 'Use env var for internal URL' });
        }
      },
    };
  },
};
```

### Type-aware rule (no-floating-promise)
```typescript
// 매 typescript-eslint 의 type info 의 use
import { ESLintUtils } from '@typescript-eslint/utils';

export const noUnsafePromise = ESLintUtils.RuleCreator(name => name)({
  name: 'no-unsafe-promise',
  meta: { type: 'problem', docs: { description: '...' }, schema: [], messages: { msg: '...' } },
  defaultOptions: [],
  create(context) {
    const services = ESLintUtils.getParserServices(context);
    const checker = services.program.getTypeChecker();
    return {
      AwaitExpression(node) {
        const type = checker.getTypeAtLocation(services.esTreeNodeToTSNodeMap.get(node.argument));
        // 매 type-based logic
      },
    };
  },
});
```

### CI integration (GitHub Actions)
```yaml
- run: npx eslint . --max-warnings 0 --format json -o eslint.json
- uses: ataylorme/eslint-annotate-action@v3
  with: { report-json: eslint.json }
```

### Pre-commit (lint-staged)
```json
{
  "lint-staged": {
    "*.{ts,tsx}": ["eslint --fix", "prettier --write"]
  }
}
```

### Migrate to Biome (faster)
```json
// biome.json
{
  "$schema": "https://biomejs.dev/schemas/1.9.0/schema.json",
  "linter": {
    "enabled": true,
    "rules": { "recommended": true, "complexity": { "noForEach": "error" } }
  },
  "formatter": { "enabled": true, "indentWidth": 2 }
}
// 매 npx @biomejs/biome lint .
```

### oxlint (Rust, fastest)
```bash
npx oxlint@latest . --deny correctness --deny perf
# 매 50-100x faster than ESLint
```

### Disable inline (justified)
```typescript
// eslint-disable-next-line @typescript-eslint/no-explicit-any -- 매 third-party type 의 incomplete
const data = response as any;
```

### LLM-generated rule
```python
def llm_generate_rule(description):
    prompt = f"""Generate an ESLint custom rule.

Description: {description}

Output JS module with meta + create."""
    return llm.generate(prompt)
```

## 매 결정 기준
| 상황 | Tool |
|---|---|
| Standard JS/TS | ESLint flat config |
| Speed-critical CI | Biome / oxlint |
| Type-aware | typescript-eslint |
| Custom team rule | ESLint custom rule |
| Format only | Prettier / Biome |
| Security | + eslint-plugin-security / Snyk Code |

**기본값**: 매 ESLint flat + 매 typescript-eslint + 매 Biome (format) + 매 lint-staged + 매 CI annotate.

## 🔗 Graph
- 부모: [[Static-Analysis]] · [[Code-Quality]]
- 변형: [[Custom-ESLint-Rules-Development]] · [[Biome]] · [[oxlint]]
- 응용: [[CI-CD]]
- Adjacent: [[Prettier]] · [[TypeScript]] · [[Corgea]]

## 🤖 LLM 활용
**언제**: 매 codebase standard. 매 team scale. 매 anti-pattern enforce.
**언제 X**: 매 prototype throwaway.

## ❌ 안티패턴
- **Disable everything**: 매 lint 의 useless.
- **Old .eslintrc legacy** (post-2024): 매 flat config 의 migrate.
- **No type-aware in TS**: 매 false confidence.
- **Lint at PR only**: 매 friction → 매 pre-commit.
- **No autofix**: 매 manual fatigue.

## 🧪 검증 / 중복
- Verified (ESLint v9 docs, typescript-eslint, Biome).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-04-20 | Auto-reinforced |
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — flat config + custom rule + Biome / oxlint + CI / pre-commit code |