2nd/10_Wiki/Topics/Frontend/ESLint-Plugin-Development.md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-eslint-plugin-development	ESLint Plugin Development	10_Wiki/Topics	verified	self	ESLint Custom Rules ESLint Plugin Authoring	none	A	0.9	applied	eslint plugin ast linting		2026-05-10	pending	language framework JavaScript/TypeScript ESLint 9

ESLint Plugin Development

매 한 줄

"매 ESLint plugin은 AST visitor + RuleTester.". ESLint 9 (2024-) Flat config 시대에는 plugin = {rules, configs, processors} object 의 export. 매 rule = meta (docs, fixable, schema) + create(context) returning visitor map (e.g., CallExpression(node) { ... }).

매 핵심

매 AST 기반

• ESLint = ESTree spec (espree parser default; @typescript-eslint/parser for TS).
• 매 rule visitor가 specific node type 방문 — Identifier, CallExpression, JSXElement 등.
• context.report({node, message, fix}) 으로 violation 보고.

매 Plugin shape (Flat config)

• ESLint 9+ deprecated .eslintrc 형식 — 매 eslint.config.js flat config.
• Plugin export = {meta, rules, configs, processors} — meta에 name/version 명시.

매 응용

1. Internal style guide — 매 monorepo 의 component naming, import order.
2. Framework rules — eslint-plugin-react, eslint-plugin-vue 처럼 framework-specific.
3. Security lint — 매 dangerous API (eval, innerHTML) 금지.
4. Migration codemod — 매 deprecated API 의 자동 fixer.

💻 패턴

1. Minimal rule skeleton

// rules/no-foo.js
export default {
  meta: {
    type: 'problem',
    docs: { description: 'disallow Foo identifier', recommended: true },
    fixable: 'code',
    schema: [],
    messages: { unexpected: "'{{name}}' is not allowed." },
  },
  create(context) {
    return {
      Identifier(node) {
        if (node.name === 'Foo') {
          context.report({
            node,
            messageId: 'unexpected',
            data: { name: node.name },
            fix: (fixer) => fixer.replaceText(node, 'Bar'),
          });
        }
      },
    };
  },
};

2. Plugin entry (ESM, ESLint 9 flat)

// index.js
import noFoo from './rules/no-foo.js';

const plugin = {
  meta: { name: 'eslint-plugin-acme', version: '1.0.0' },
  rules: { 'no-foo': noFoo },
};

plugin.configs = {
  recommended: {
    plugins: { acme: plugin },
    rules: { 'acme/no-foo': 'error' },
  },
};

export default plugin;

3. Consumer flat config

// eslint.config.js
import acme from 'eslint-plugin-acme';

export default [
  acme.configs.recommended,
  { rules: { 'acme/no-foo': ['error'] } },
];

4. RuleTester (built-in test)

import { RuleTester } from 'eslint';
import rule from '../rules/no-foo.js';

const tester = new RuleTester({
  languageOptions: { ecmaVersion: 2024, sourceType: 'module' },
});

tester.run('no-foo', rule, {
  valid: ['const Bar = 1;'],
  invalid: [{
    code: 'const Foo = 1;',
    errors: [{ messageId: 'unexpected' }],
    output: 'const Bar = 1;',
  }],
});

5. TypeScript rule with @typescript-eslint

import { ESLintUtils } from '@typescript-eslint/utils';

const createRule = ESLintUtils.RuleCreator(
  (name) => `https://acme.dev/rules/${name}`,
);

export default createRule({
  name: 'no-any',
  meta: {
    type: 'suggestion',
    docs: { description: 'disallow any' },
    schema: [],
    messages: { noAny: 'Avoid any; use unknown.' },
  },
  defaultOptions: [],
  create(context) {
    return {
      TSAnyKeyword(node) {
        context.report({ node, messageId: 'noAny' });
      },
    };
  },
});

6. Suggestions (non-auto fix)

context.report({
  node,
  messageId: 'considerRename',
  suggest: [{
    messageId: 'renameToBar',
    fix: (fixer) => fixer.replaceText(node, 'Bar'),
  }],
});

7. AST exploration (astexplorer.net)

// Visitor pattern — leverage selector strings
return {
  'CallExpression[callee.name="eval"]'(node) {
    context.report({ node, message: 'eval disallowed' });
  },
};

8. Scope / variable analysis

create(context) {
  return {
    Identifier(node) {
      const scope = context.sourceCode.getScope(node);
      const variable = scope.references.find((r) => r.identifier === node);
      if (variable?.resolved?.defs[0]?.type === 'ImportBinding') {
        // imported identifier
      }
    },
  };
}

매 결정 기준

상황	Approach
Codebase-specific 매 규칙	Internal plugin (private npm).
OSS 공유	Publish eslint-plugin-foo.
TS-only	@typescript-eslint/utils RuleCreator.
매 codemod 용	jscodeshift / ts-morph (ESLint fix 보다 more powerful).
매 단순 ban API	no-restricted-syntax config — plugin 불필요.

기본값: 매 ESLint 9 flat config + @typescript-eslint/utils RuleCreator.

🔗 Graph

• 부모: ESLint · AST
• 변형: Biome
• Adjacent: Prettier · TypeScript

🤖 LLM 활용

언제: AST visitor 작성, RuleTester case 생성, 매 selector string 의 작성. 언제 X: 매 cross-file 분석 (ESLint = single-file) — 매 ts-morph / lsif 사용.

❌ 안티패턴

• Regex on source: 매 source string regex 의 X — 매 AST 사용.
• No tests: 매 RuleTester 없는 rule 의 X — false positive 의 즉시 발생.
• Auto-fix without safety: 매 fix가 매 semantics 변경 시 suggest 사용.
• .eslintrc in 2026: 매 flat config 으로 migrate.

🧪 검증 / 중복

• Verified (ESLint 9 docs, eslint.org/docs/latest/extend).
• 신뢰도 A.

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — ESLint 9 flat config plugin authoring 패턴