From 591c43fb2937d73864aa5d75792fe2cc963e562d Mon Sep 17 00:00:00 2001
From: mayrang <pkss0626@naver.com>
Date: Fri, 17 Apr 2026 18:27:47 +0900
Subject: [PATCH 1/3] =?UTF-8?q?fix:=20classify=20Hangul=20Compatibility=20?=
 =?UTF-8?q?Jamo=20(U+3130=E2=80=93U+318F)=20as=20CJK?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

isCJKCodePoint() included Hangul syllables (U+AC00–U+D7AF) but not
Hangul Compatibility Jamo (U+3130–U+318F), the standalone consonants
and vowels (ㄱ ㄴ ㄷ ㅋ ㅠ ...) used constantly in Korean digital text.

Without CJK classification these characters were treated as atomic
segments the line-breaker could not split at grapheme boundaries,
producing line counts 1 too high for common expressions like ㅋㅋ, ㄹㅇ.

Verified against Chrome and Safari.
---
 src/analysis.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/analysis.ts b/src/analysis.ts
index 4abdac4..15c2ca8 100644
--- a/src/analysis.ts
+++ b/src/analysis.ts
@@ -121,6 +121,7 @@ function isCJKCodePoint(codePoint: number): boolean {
     (codePoint >= 0x3000 && codePoint <= 0x303F) ||
     (codePoint >= 0x3040 && codePoint <= 0x309F) ||
     (codePoint >= 0x30A0 && codePoint <= 0x30FF) ||
+    (codePoint >= 0x3130 && codePoint <= 0x318F) ||  // Hangul Compatibility Jamo (ㄱ-ㅣ)
     (codePoint >= 0xAC00 && codePoint <= 0xD7AF) ||
     (codePoint >= 0xFF00 && codePoint <= 0xFFEF)
   )

From 08b5ffa2fea12a5449510f4d1e3ff451e349f6fe Mon Sep 17 00:00:00 2001
From: mayrang <pkss0626@naver.com>
Date: Fri, 17 Apr 2026 18:27:47 +0900
Subject: [PATCH 2/3] fix: add korean-check oracle for Hangul edge cases and
 layout modes

---
 package.json            |   1 +
 scripts/korean-check.ts | 344 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 345 insertions(+)
 create mode 100644 scripts/korean-check.ts

diff --git a/package.json b/package.json
index 4e0c932..422bbc4 100644
--- a/package.json
+++ b/package.json
@@ -68,6 +68,7 @@
     "corpus-taxonomy": "bun run scripts/corpus-taxonomy.ts",
     "generate:bidi-data": "bun run scripts/generate-bidi-data.ts",
     "keep-all-check": "bun run scripts/keep-all-check.ts",
+    "korean-check": "bun run scripts/korean-check.ts",
     "package-smoke-test": "bun run scripts/package-smoke-test.ts",
     "prepack": "rm -rf dist && tsc -p tsconfig.build.json",
     "pre-wrap-check": "bun run scripts/pre-wrap-check.ts",
diff --git a/scripts/korean-check.ts b/scripts/korean-check.ts
new file mode 100644
index 0000000..3701131
--- /dev/null
+++ b/scripts/korean-check.ts
@@ -0,0 +1,344 @@
+import { type ChildProcess } from 'node:child_process'
+import {
+  acquireBrowserAutomationLock,
+  createBrowserSession,
+  ensurePageServer,
+  getAvailablePort,
+  loadHashReport,
+  type AutomationBrowserKind,
+  type BrowserKind,
+} from './browser-automation.ts'
+
+type ProbeReport = {
+  status: 'ready' | 'error'
+  requestId?: string
+  browserLineMethod?: 'range' | 'span'
+  width?: number
+  predictedHeight?: number
+  actualHeight?: number
+  diffPx?: number
+  predictedLineCount?: number
+  browserLineCount?: number
+  firstBreakMismatch?: {
+    line: number
+    deltaText: string
+    reasonGuess: string
+    oursText: string
+    browserText: string
+  } | null
+  extractorSensitivity?: string | null
+  message?: string
+}
+
+type OracleCase = {
+  label: string
+  text: string
+  width: number
+  font: string
+  lineHeight: number
+  lang: string
+  dir?: 'ltr' | 'rtl'
+  whiteSpace?: 'normal' | 'pre-wrap'
+  wordBreak?: 'normal' | 'keep-all'
+}
+
+const ORACLE_CASES: OracleCase[] = [
+  // B: Edge cases — normal mode
+  {
+    label: 'B1: 한글 자모 단독 (U+1100)',
+    text: 'ᄀᄂᄃ 테스트 ᄀᄂᄃ 테스트 ᄀᄂᄃ',
+    width: 200,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B2: 한글 호환 자모 (U+3130)',
+    text: 'ㄱㄴㄷ 호환 자모 ㄱㄴㄷ 호환 자모 ㄱㄴㄷ',
+    width: 200,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B3: 한글+영어 혼합',
+    text: '안녕 Hello 세계 안녕 Hello 세계',
+    width: 200,
+    font: '20px "Apple SD Gothic Neo"',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B4: 한글+숫자',
+    text: '가격은 10,000원 입니다 배송은 3,500원 입니다',
+    width: 200,
+    font: '20px "Apple SD Gothic Neo"',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B5: 한글+CJK 구두점',
+    text: '안녕하세요。잘 부탁합니다。감사합니다。',
+    width: 200,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B6: NBSP + 한글',
+    text: '서울\u00A0시청역 부산\u00A0역',
+    width: 150,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  // B2-width-variants: same texts at different widths to confirm bug is width-sensitive
+  {
+    label: 'B2c-w160: ㅠㅠ 감정 (160px)',
+    text: 'ㅠㅠ 너무 슬퍼요 ㅠㅠ 정말로',
+    width: 160,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B2c-w140: ㅠㅠ 감정 (140px)',
+    text: 'ㅠㅠ 너무 슬퍼요 ㅠㅠ 정말로',
+    width: 140,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B2d-w150: ㄹㅇ 슬랭 (150px)',
+    text: '이거 ㄹㅇ임 ㄹㅇ 아니면 뭐야',
+    width: 150,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B2f-w150: ㅇㅋ ㄴㄴ (150px)',
+    text: 'ㅇㅋ 알겠어요 ㄴㄴ 그건 아니고',
+    width: 150,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  // B2-variants: Hangul Compatibility Jamo edge cases (the confirmed bug)
+  {
+    label: 'B2b: ㅋㅋ 슬랭 혼합',
+    text: 'ㅋㅋㅋ 진짜 웃기다 ㅋㅋㅋ 진짜로',
+    width: 200,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B2c: ㅠㅠ 감정 표현',
+    text: 'ㅠㅠ 너무 슬퍼요 ㅠㅠ 정말로',
+    width: 200,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B2d: 자음 단독 문장 중간',
+    text: '이거 ㄹㅇ임 ㄹㅇ 아니면 뭐야',
+    width: 180,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B2e: 자음만 연속',
+    text: 'ㄱㄴㄷㄹㅁㅂㅅㅇㅈㅊㅋㅌㅍㅎ',
+    width: 150,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  {
+    label: 'B2f: ㅇㅋ ㄴㄴ 인터넷 슬랭',
+    text: 'ㅇㅋ 알겠어요 ㄴㄴ 그건 아니고',
+    width: 180,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+  },
+  // C: Layout modes
+  {
+    label: 'C1: keep-all + 좁은 너비',
+    text: '한국어 테스트 입니다',
+    width: 80,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+    wordBreak: 'keep-all',
+  },
+  {
+    label: 'C2: keep-all + 한글+영어 혼합',
+    text: '한국어 Korean 혼합 테스트',
+    width: 150,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+    wordBreak: 'keep-all',
+  },
+  {
+    label: 'C3: pre-wrap + 한글 하드 브레이크',
+    text: '가나다\n라마바',
+    width: 300,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+    whiteSpace: 'pre-wrap',
+  },
+  {
+    label: 'C4: pre-wrap + 탭 + 한글',
+    text: '가나\t다라',
+    width: 300,
+    font: '20px serif',
+    lineHeight: 34,
+    lang: 'ko',
+    whiteSpace: 'pre-wrap',
+  },
+]
+
+function parseStringFlag(name: string): string | null {
+  const prefix = `--${name}=`
+  const arg = process.argv.find(value => value.startsWith(prefix))
+  return arg === undefined ? null : arg.slice(prefix.length)
+}
+
+function parseNumberFlag(name: string, fallback: number): number {
+  const raw = parseStringFlag(name)
+  if (raw === null) return fallback
+  const parsed = Number.parseInt(raw, 10)
+  if (!Number.isFinite(parsed)) throw new Error(`Invalid value for --${name}: ${raw}`)
+  return parsed
+}
+
+function parseBrowsers(value: string | null): AutomationBrowserKind[] {
+  const raw = (value ?? 'chrome,safari').trim()
+  if (raw.length === 0) return ['chrome', 'safari']
+
+  const browsers = raw
+    .split(',')
+    .map(part => part.trim().toLowerCase())
+    .filter(Boolean)
+
+  for (const browser of browsers) {
+    if (browser !== 'chrome' && browser !== 'safari' && browser !== 'firefox') {
+      throw new Error(`Unsupported browser ${browser}`)
+    }
+  }
+
+  return browsers as AutomationBrowserKind[]
+}
+
+function buildProbeUrl(baseUrl: string, requestId: string, testCase: OracleCase): string {
+  const dir = testCase.dir ?? 'ltr'
+  const whiteSpace = testCase.whiteSpace ?? 'normal'
+  const wordBreak = testCase.wordBreak ?? 'normal'
+  return (
+    `${baseUrl}/probe?text=${encodeURIComponent(testCase.text)}` +
+    `&width=${testCase.width}` +
+    `&font=${encodeURIComponent(testCase.font)}` +
+    `&lineHeight=${testCase.lineHeight}` +
+    `&dir=${encodeURIComponent(dir)}` +
+    `&lang=${encodeURIComponent(testCase.lang)}` +
+    `&whiteSpace=${encodeURIComponent(whiteSpace)}` +
+    `&wordBreak=${encodeURIComponent(wordBreak)}` +
+    `&method=span` +
+    `&requestId=${encodeURIComponent(requestId)}`
+  )
+}
+
+function reportIsExact(report: ProbeReport): boolean {
+  return (
+    report.status === 'ready' &&
+    report.diffPx === 0 &&
+    report.predictedLineCount === report.browserLineCount &&
+    report.predictedHeight === report.actualHeight &&
+    report.firstBreakMismatch === null
+  )
+}
+
+function printCaseResult(browser: AutomationBrowserKind, testCase: OracleCase, report: ProbeReport): void {
+  if (report.status === 'error') {
+    console.log(`  FAIL  ${testCase.label}: error: ${report.message ?? 'unknown error'}`)
+    return
+  }
+
+  const pass = reportIsExact(report)
+  const icon = pass ? '✓ PASS' : '✗ FAIL'
+  const lines = `[${report.predictedLineCount} lines]`
+  const detail = pass
+    ? lines
+    : `expected=${report.browserLineCount} got=${report.predictedLineCount}  width=${testCase.width}px font=${testCase.font}`
+
+  console.log(`  ${icon}  ${testCase.label.padEnd(40)} ${detail}`)
+
+  if (!pass && report.firstBreakMismatch != null) {
+    console.log(
+      `         break L${report.firstBreakMismatch.line}: ${report.firstBreakMismatch.reasonGuess} | ` +
+      `ours ${JSON.stringify(report.firstBreakMismatch.oursText)} | ` +
+      `browser ${JSON.stringify(report.firstBreakMismatch.browserText)}`,
+    )
+  }
+}
+
+async function runBrowser(browser: AutomationBrowserKind, port: number): Promise<boolean> {
+  const lock = await acquireBrowserAutomationLock(browser)
+  const reportBrowser: BrowserKind | null = browser === 'firefox' ? null : browser
+  const session = reportBrowser === null ? null : createBrowserSession(reportBrowser)
+  let serverProcess: ChildProcess | null = null
+  let ok = true
+  let pass = 0
+
+  try {
+    if (session === null || reportBrowser === null) {
+      throw new Error('Firefox is not supported for korean oracle checks')
+    }
+
+    const pageServer = await ensurePageServer(port, '/probe', process.cwd())
+    serverProcess = pageServer.process
+
+    console.log(`\nKorean Layout Check — ${browser.charAt(0).toUpperCase() + browser.slice(1)}`)
+    console.log('─'.repeat(60))
+
+    for (const testCase of ORACLE_CASES) {
+      const requestId = `${browser}-${Date.now()}-${Math.random().toString(36).slice(2)}`
+      const url = buildProbeUrl(pageServer.baseUrl, requestId, testCase)
+      const report = await loadHashReport<ProbeReport>(session, url, requestId, reportBrowser, timeoutMs)
+      printCaseResult(browser, testCase, report)
+      if (reportIsExact(report)) {
+        pass++
+      } else {
+        ok = false
+      }
+    }
+
+    console.log(`\nSummary: ${browser} ${pass}/${ORACLE_CASES.length} pass`)
+  } finally {
+    session?.close()
+    serverProcess?.kill()
+    lock.release()
+  }
+
+  return ok
+}
+
+const requestedPort = parseNumberFlag('port', 0)
+const browsers = parseBrowsers(parseStringFlag('browser'))
+const timeoutMs = parseNumberFlag('timeout', 60_000)
+
+const port = await getAvailablePort(requestedPort === 0 ? null : requestedPort)
+let overallOk = true
+for (const browser of browsers) {
+  const browserOk = await runBrowser(browser, port)
+  if (!browserOk) overallOk = false
+}
+
+if (!overallOk) process.exitCode = 1

From 00025d7e81148fe11869e9e86ad84834e7d328dc Mon Sep 17 00:00:00 2001
From: mayrang <pkss0626@naver.com>
Date: Fri, 17 Apr 2026 22:53:07 +0900
Subject: [PATCH 3/3] fix: translate korean-check labels to English

---
 scripts/korean-check.ts | 38 +++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/scripts/korean-check.ts b/scripts/korean-check.ts
index 3701131..c9e056a 100644
--- a/scripts/korean-check.ts
+++ b/scripts/korean-check.ts
@@ -45,7 +45,7 @@ type OracleCase = {
 const ORACLE_CASES: OracleCase[] = [
   // B: Edge cases — normal mode
   {
-    label: 'B1: 한글 자모 단독 (U+1100)',
+    label: 'B1: Hangul Jamo standalone (U+1100)',
     text: 'ᄀᄂᄃ 테스트 ᄀᄂᄃ 테스트 ᄀᄂᄃ',
     width: 200,
     font: '20px serif',
@@ -53,7 +53,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B2: 한글 호환 자모 (U+3130)',
+    label: 'B2: Hangul Compatibility Jamo (U+3130)',
     text: 'ㄱㄴㄷ 호환 자모 ㄱㄴㄷ 호환 자모 ㄱㄴㄷ',
     width: 200,
     font: '20px serif',
@@ -61,7 +61,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B3: 한글+영어 혼합',
+    label: 'B3: Korean+English mixed',
     text: '안녕 Hello 세계 안녕 Hello 세계',
     width: 200,
     font: '20px "Apple SD Gothic Neo"',
@@ -69,7 +69,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B4: 한글+숫자',
+    label: 'B4: Korean+numbers mixed',
     text: '가격은 10,000원 입니다 배송은 3,500원 입니다',
     width: 200,
     font: '20px "Apple SD Gothic Neo"',
@@ -77,7 +77,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B5: 한글+CJK 구두점',
+    label: 'B5: Korean+CJK punctuation',
     text: '안녕하세요。잘 부탁합니다。감사합니다。',
     width: 200,
     font: '20px serif',
@@ -85,7 +85,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B6: NBSP + 한글',
+    label: 'B6: NBSP + Korean',
     text: '서울\u00A0시청역 부산\u00A0역',
     width: 150,
     font: '20px serif',
@@ -94,7 +94,7 @@ const ORACLE_CASES: OracleCase[] = [
   },
   // B2-width-variants: same texts at different widths to confirm bug is width-sensitive
   {
-    label: 'B2c-w160: ㅠㅠ 감정 (160px)',
+    label: 'B2c-w160: ㅠㅠ crying expression (160px)',
     text: 'ㅠㅠ 너무 슬퍼요 ㅠㅠ 정말로',
     width: 160,
     font: '20px serif',
@@ -102,7 +102,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B2c-w140: ㅠㅠ 감정 (140px)',
+    label: 'B2c-w140: ㅠㅠ crying expression (140px)',
     text: 'ㅠㅠ 너무 슬퍼요 ㅠㅠ 정말로',
     width: 140,
     font: '20px serif',
@@ -110,7 +110,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B2d-w150: ㄹㅇ 슬랭 (150px)',
+    label: 'B2d-w150: ㄹㅇ literally slang (150px)',
     text: '이거 ㄹㅇ임 ㄹㅇ 아니면 뭐야',
     width: 150,
     font: '20px serif',
@@ -118,7 +118,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B2f-w150: ㅇㅋ ㄴㄴ (150px)',
+    label: 'B2f-w150: ㅇㅋ/ㄴㄴ okay/nope slang (150px)',
     text: 'ㅇㅋ 알겠어요 ㄴㄴ 그건 아니고',
     width: 150,
     font: '20px serif',
@@ -127,7 +127,7 @@ const ORACLE_CASES: OracleCase[] = [
   },
   // B2-variants: Hangul Compatibility Jamo edge cases (the confirmed bug)
   {
-    label: 'B2b: ㅋㅋ 슬랭 혼합',
+    label: 'B2b: ㅋㅋ laughter slang mixed',
     text: 'ㅋㅋㅋ 진짜 웃기다 ㅋㅋㅋ 진짜로',
     width: 200,
     font: '20px serif',
@@ -135,7 +135,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B2c: ㅠㅠ 감정 표현',
+    label: 'B2c: ㅠㅠ crying expression',
     text: 'ㅠㅠ 너무 슬퍼요 ㅠㅠ 정말로',
     width: 200,
     font: '20px serif',
@@ -143,7 +143,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B2d: 자음 단독 문장 중간',
+    label: 'B2d: ㄹㅇ literally slang mid-sentence',
     text: '이거 ㄹㅇ임 ㄹㅇ 아니면 뭐야',
     width: 180,
     font: '20px serif',
@@ -151,7 +151,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B2e: 자음만 연속',
+    label: 'B2e: consonants-only run',
     text: 'ㄱㄴㄷㄹㅁㅂㅅㅇㅈㅊㅋㅌㅍㅎ',
     width: 150,
     font: '20px serif',
@@ -159,7 +159,7 @@ const ORACLE_CASES: OracleCase[] = [
     lang: 'ko',
   },
   {
-    label: 'B2f: ㅇㅋ ㄴㄴ 인터넷 슬랭',
+    label: 'B2f: ㅇㅋ/ㄴㄴ okay/nope internet slang',
     text: 'ㅇㅋ 알겠어요 ㄴㄴ 그건 아니고',
     width: 180,
     font: '20px serif',
@@ -168,7 +168,7 @@ const ORACLE_CASES: OracleCase[] = [
   },
   // C: Layout modes
   {
-    label: 'C1: keep-all + 좁은 너비',
+    label: 'C1: keep-all + narrow width',
     text: '한국어 테스트 입니다',
     width: 80,
     font: '20px serif',
@@ -177,7 +177,7 @@ const ORACLE_CASES: OracleCase[] = [
     wordBreak: 'keep-all',
   },
   {
-    label: 'C2: keep-all + 한글+영어 혼합',
+    label: 'C2: keep-all + Korean+English mixed',
     text: '한국어 Korean 혼합 테스트',
     width: 150,
     font: '20px serif',
@@ -186,7 +186,7 @@ const ORACLE_CASES: OracleCase[] = [
     wordBreak: 'keep-all',
   },
   {
-    label: 'C3: pre-wrap + 한글 하드 브레이크',
+    label: 'C3: pre-wrap + Korean hard break',
     text: '가나다\n라마바',
     width: 300,
     font: '20px serif',
@@ -195,7 +195,7 @@ const ORACLE_CASES: OracleCase[] = [
     whiteSpace: 'pre-wrap',
   },
   {
-    label: 'C4: pre-wrap + 탭 + 한글',
+    label: 'C4: pre-wrap + tab + Korean',
     text: '가나\t다라',
     width: 300,
     font: '20px serif',