MAIN_PLAN.md

@@ -95,6 +95,14 @@
  - Exporter CSS 토큰 회귀 확대(:root --primary, body font, skip-link base/focus, focus outline, reduced-motion)
  - 컴포넌트 i18n 회귀 스냅샷(en/ko 주요 라벨/버튼 키 존재)
  - 섹션 a11y 자동 검증 템플릿(testUtils/sectionA11y) 도입 및 템플릿 테스트 추가
+ - 이미지 최적화 옵션 1차(TDD): hero 이미지에 `fetchpriority`/`srcset`/`sizes` 조건부 렌더링
+  - 테스트: `lib/exporter/image.responsive.options.test.ts` (속성 존재 검증)
+  - 구현: `lib/exporter/html.ts`(`ExportOptions`에 옵션 추가 및 `<img>` 렌더 반영)
+  - 브랜치: `feat/image-optimization` (로컬 커밋, 푸쉬 보류)
+ - 이미지 최적화 옵션 2차(TDD): `srcset`만 제공 시 기본 `sizes` 자동 적용(`imageAutoSizes`)
+  - 기본값: `(max-width: 640px) 100vw, 600px`
+  - 테스트: `image.responsive.options.test.ts` (auto on/off 케이스)
+  - 구현: `ExportOptions.imageAutoSizes` 추가 및 `renderHero` 적용
   - 신규 섹션 추가: Benefits
   - 스키마 확장(`benefits`): props.items:string[]
   - Exporter 렌더 추가: `<section class="benefits" aria-labelledby>`, `<h2 id="benefits-heading">`, 리스트 렌더
@@ -373,6 +381,7 @@
 - `verifyIntegrity` 결과에 `summary`(total/missing/integrityMismatches/sizeMismatches/bundleHashMismatch) 추가
 - Export Options(폰트 프리커넥트/프리로드, 이미지 로딩/디코딩, robots 메타) UI/문서화
 - 브랜치 푸쉬 완료: `feat/export-bundle-integrity`
+ - 이미지 최적화 옵션(1차): `fetchpriority`/`srcset`/`sizes` 추가 및 테스트 그린
 
 ### 하드닝
 - ZIP 경로 가드: `../`, 절대경로(`/`), 역슬래시(`\`) 차단 (테스트 포함)
@@ -392,6 +401,7 @@
 2) CI 무결성 검증 스텝 추가: `verifyIntegrity`로 빌드 산출물 검사(요약 리포트 로깅)
 3) PR 라벨 자동화 및 조건부 머지(Gitea Actions/웹훅)
 4) README에 사용 가이드 보완(verifyIntegrity 활용 예시)
+5) 이미지 최적화 2차: `sizes` 기본 정책 프리셋 및 변환 파이프라인(AVIF/WebP) 설계 초안(TDD 스텁)
 
 ### CI/CD 계획(초안)
 - PR 오픈 시: 라벨 자동 지정, 테스트/빌드, 무결성 검증 스텝 실행

README.md

@@ -63,6 +63,13 @@ The Builder can export a production-ready ZIP that contains:
 - Image Options
   - Loading: `lazy` (default) or `eager` for `<img loading>`
   - Decoding: `async` (default) or `sync` for `<img decoding>`
+  - Fetch Priority: optional `high|low` for `<img fetchpriority>`
+  - Srcset/Sizes: optional responsive sources via `<img srcset>` and `<img sizes>`
+  - Auto Sizes: when enabled and only `srcset` is provided, a sensible default is applied to `<img sizes>`: `(max-width: 640px) 100vw, 600px`
+  - Sizes Preset: choose a preset for `<img sizes>` when `imageSizes` is not set.
+    - `mobile-first`: `(max-width: 640px) 100vw, 800px`
+    - `desktop-fixed`: `1200px`
+  - Precedence: explicit `imageSizes` > `imageSizesPreset` > `imageAutoSizes` > none
 
 ### site.webmanifest and robots.txt
 

lib/exporter/html.ts

@@ -12,6 +12,8 @@ export type ExportOptions = {
   imageFetchPriority?: 'high' | 'low'
   imageSrcset?: string
   imageSizes?: string
+  imageAutoSizes?: boolean
+  imageSizesPreset?: 'mobile-first' | 'desktop-fixed'
 }
 
 function renderFaq(section: { props: { items: Array<{ q: string; a: string }> } }) {
@@ -130,7 +132,15 @@ function renderHero(section: { props: { heading: string; subheading?: string; im
   const decoding = opts?.imageDecoding ?? 'async'
   const fetchpriority = opts?.imageFetchPriority ? ` fetchpriority="${escapeHtml(opts.imageFetchPriority)}"` : ''
   const srcset = opts?.imageSrcset ? ` srcset="${escapeHtml(opts.imageSrcset)}"` : ''
-  const sizes = opts?.imageSizes ? ` sizes="${escapeHtml(opts.imageSizes)}"` : ''
+  const defaultSizes = '(max-width: 640px) 100vw, 600px'
+  const presetSizes = (() => {
+    if (!opts?.imageSizesPreset) return ''
+    if (opts.imageSizesPreset === 'mobile-first') return '(max-width: 640px) 100vw, 800px'
+    if (opts.imageSizesPreset === 'desktop-fixed') return '1200px'
+    return ''
+  })()
+  const sizesValue = opts?.imageSizes ?? (presetSizes || (opts?.imageSrcset && opts?.imageAutoSizes ? defaultSizes : ''))
+  const sizes = sizesValue ? ` sizes="${escapeHtml(sizesValue)}"` : ''
   return `
     <section class="hero" aria-labelledby="hero-heading">
       <div class="container">

lib/exporter/image.responsive.options.test.ts

@@ -35,4 +35,53 @@ describe('image responsive/export options', () => {
     expect(html).toMatch(/<img[^>]*srcset="https:\/\/example.com\/hero.jpg 1x, https:\/\/example.com\/hero@2x.jpg 2x"/)
     expect(html).toMatch(/<img[^>]*sizes="\(max-width: 640px\) 100vw, 600px"/)
   })
+
+  it('applies default sizes when srcset is provided and imageAutoSizes is true', () => {
+    const options: ExportOptions = {
+      imageSrcset: 'https://example.com/hero.jpg 1x, https://example.com/hero@2x.jpg 2x',
+      imageAutoSizes: true,
+    }
+    const { html } = exportPage(basePage, options)
+    expect(html).toMatch(/<img[^>]*srcset="https:\/\/example.com\/hero.jpg 1x, https:\/\/example.com\/hero@2x.jpg 2x"/)
+    expect(html).toMatch(/<img[^>]*sizes="\(max-width: 640px\) 100vw, 600px"/)
+  })
+
+  it('does not include sizes when srcset is provided but imageAutoSizes is false and sizes not provided', () => {
+    const options: ExportOptions = {
+      imageSrcset: 'https://example.com/hero.jpg 1x, https://example.com/hero@2x.jpg 2x',
+      imageAutoSizes: false,
+    }
+    const { html } = exportPage(basePage, options)
+    expect(html).toMatch(/<img[^>]*srcset="https:\/\/example.com\/hero.jpg 1x, https:\/\/example.com\/hero@2x.jpg 2x"/)
+    expect(html).not.toMatch(/<img[^>]*sizes="/)
+  })
+
+  it('applies preset sizes when imageSizesPreset is set (mobile-first)', () => {
+    const options: ExportOptions = {
+      imageSrcset: 'https://example.com/hero.jpg 1x, https://example.com/hero@2x.jpg 2x',
+      imageSizesPreset: 'mobile-first',
+    }
+    const { html } = exportPage(basePage, options)
+    expect(html).toMatch(/<img[^>]*sizes="\(max-width: 640px\) 100vw, 800px"/)
+  })
+
+  it('applies desktop-fixed preset when selected', () => {
+    const options: ExportOptions = {
+      imageSrcset: 'https://example.com/hero.jpg 1x, https://example.com/hero@2x.jpg 2x',
+      imageSizesPreset: 'desktop-fixed',
+    }
+    const { html } = exportPage(basePage, options)
+    expect(html).toMatch(/<img[^>]*sizes="1200px"/)
+  })
+
+  it('explicit imageSizes overrides presets and auto', () => {
+    const options: ExportOptions = {
+      imageSrcset: 'https://example.com/hero.jpg 1x, https://example.com/hero@2x.jpg 2x',
+      imageAutoSizes: true,
+      imageSizesPreset: 'desktop-fixed',
+      imageSizes: '(max-width: 768px) 100vw, 700px',
+    }
+    const { html } = exportPage(basePage, options)
+    expect(html).toMatch(/<img[^>]*sizes="\(max-width: 768px\) 100vw, 700px"/)
+  })
 })