chore: import upstream snapshot with attribution

scripts/pr-labels/README.md

@@ -0,0 +1,58 @@
+# PR Label Sync
+
+This directory contains scripts and sample data for automatically classifying and labeling GitHub Pull Requests based on the files they modify.
+
+## Files
+
+- `index.js`: The main Node.js script. It fetches PR files, evaluates their risk level, calculates business impact, and uses GitHub APIs to add appropriate `size/*` and `domain/*` labels.
+- `samples.json`: A collection of historical PRs used as test cases to verify the labeling logic (especially for regression testing the S/M/L thresholds).
+
+## Features
+
+### Size Labels (`size/*`)
+The script evaluates the "effective" lines of code changed (ignoring tests, docs, and ci files) to classify the PR:
+- **`size/S`**: Low-risk changes involving only docs, tests, CI workflows, or chores.
+- **`size/M`**: Small-to-medium changes affecting a single business domain, with effective lines under 300.
+- **`size/L`**: Large features (>= 300 lines), cross-domain changes, or any changes touching core architecture paths (like `cmd/`).
+- **`size/XL`**: Architectural overhauls, extremely large PRs (>1200 lines), or sensitive refactors.
+
+### Domain Tags (`domain/*`)
+The script also identifies which business domains a PR touches to give reviewers an immediate sense of the impact scope. Currently tracked domains include:
+- `domain/im`
+- `domain/vc`
+- `domain/ccm`
+- `domain/base`
+- `domain/mail`
+- `domain/calendar`
+- `domain/task`
+- `domain/contact`
+
+Minor modules like docs and tests are omitted to keep PR tags clean and focused on structural changes.
+
+## Usage
+
+### In GitHub Actions
+This script is designed to run in CI workflows. It automatically reads the `GITHUB_EVENT_PATH` payload to get the PR context.
+
+```bash
+node scripts/pr-labels/index.js
+```
+
+### Local Dry Run
+You can test the labeling logic against an existing GitHub PR without actually applying labels by using the `--dry-run` flag.
+
+```bash
+# Requires GITHUB_TOKEN environment variable or passing --token
+node scripts/pr-labels/index.js --dry-run --repo larksuite/cli --pr-number 123
+```
+
+## Testing
+
+A regression test suite is available in `test.js` which verifies the output of the classification logic against historical PRs configured in `samples.json`.
+
+```bash
+# Requires GITHUB_TOKEN environment variable to avoid rate limits
+GITHUB_TOKEN=$(gh auth token) node scripts/pr-labels/test.js
+```
+
+This test suite also runs automatically in CI via `.github/workflows/pr-labels-test.yml` when changes are made to this directory.

scripts/pr-labels/index.js

@@ -0,0 +1,717 @@
+#!/usr/bin/env node
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+const fs = require("node:fs/promises");
+const path = require("node:path");
+const { labelDomainsForPath } = require("../domain-map");
+
+// ============================================================================
+// Constants & Configuration
+// ============================================================================
+
+const API_BASE = "https://api.github.com";
+const SCRIPT_DIR = __dirname;
+const ROOT = path.join(SCRIPT_DIR, "..", "..");
+
+const THRESHOLD_L = 300;
+const THRESHOLD_XL = 1200;
+
+const LABEL_DEFINITIONS = {
+  "size/S": { color: "77bb00", description: "Low-risk docs, CI, test, or chore only changes" },
+  "size/M": { color: "eebb00", description: "Single-domain feat or fix with limited business impact" },
+  "size/L": { color: "ff8800", description: "Large or sensitive change across domains or core paths" },
+  "size/XL": { color: "ee0000", description: "Architecture-level or global-impact change" },
+};
+
+const MANAGED_LABELS = new Set(Object.keys(LABEL_DEFINITIONS));
+
+// File path matching configurations
+const DOC_SUFFIXES = [".md", ".mdx", ".txt", ".rst"];
+const LOW_RISK_PREFIXES = [".github/", "docs/", ".changeset/", "testdata/", "tests/", "skill-template/"];
+const LOW_RISK_FILENAMES = new Set(["readme.md", "readme.zh.md", "changelog.md", "license", "cla.md"]);
+const LOW_RISK_TEST_SUFFIXES = ["_test.go", ".snap"];
+
+const CORE_PREFIXES = ["internal/auth/", "internal/engine/", "internal/config/", "cmd/"];
+const HEAD_BUSINESS_DOMAINS = new Set(["im", "contact", "ccm", "base", "docx"]);
+const LOW_RISK_TYPES = new Set(["docs", "ci", "test", "chore"]);
+
+const SENSITIVE_PATTERN = /(^|\/)(auth|permission|permissions|security)(\/|_|\.|$)/;
+
+const CLASS_STANDARDS = {
+  "size/S": {
+    channel: "Fast track (S)",
+    gates: [
+      "Code quality: AI code review passed",
+      "Dependency and configuration security checks passed",
+    ],
+  },
+  "size/M": {
+    channel: "Fast track (M)",
+    gates: [
+      "Code quality: AI code review passed",
+      "Dependency and configuration security checks passed",
+      "Skill format validation: added or modified Skills load successfully",
+      "CLI automation tests: all required business-line tests passed",
+    ],
+  },
+  "size/L": {
+    channel: "Standard track (L)",
+    gates: [
+      "Code quality: AI code review passed",
+      "Dependency and configuration security checks passed",
+      "Skill format validation: added or modified Skills load successfully",
+      "CLI automation tests: all required business-line tests passed",
+      "Domain evaluation passed: reported success rate is greater than 95%",
+    ],
+  },
+  "size/XL": {
+    channel: "Strict track (XL)",
+    gates: [
+      "Code quality: AI code review passed",
+      "Dependency and configuration security checks passed",
+      "Skill format validation: added or modified Skills load successfully",
+      "CLI automation tests: all required business-line tests passed",
+      "Domain evaluation passed: reported success rate is greater than 95%",
+      "Cross-domain release gate: all domains and full integration evaluations passed",
+    ],
+  },
+};
+
+// ============================================================================
+// Utilities
+// ============================================================================
+
+function log(message) {
+  console.error(`sync-pr-labels: ${message}`);
+}
+
+function normalizePath(input) {
+  return String(input || "").trim().toLowerCase();
+}
+
+function envValue(name) {
+  return (process.env[name] || "").trim();
+}
+
+function envOrFail(name) {
+  const value = envValue(name);
+  if (!value) {
+    throw new Error(`missing required environment variable: ${name}`);
+  }
+  return value;
+}
+
+// ============================================================================
+// GitHub API Client
+// ============================================================================
+
+class GitHubClient {
+  constructor(token, repo, prNumber) {
+    this.token = token;
+    this.repo = repo;
+    this.prNumber = prNumber;
+  }
+
+  buildHeaders(hasBody = false) {
+    const headers = {
+      Accept: "application/vnd.github+json",
+      "X-GitHub-Api-Version": "2022-11-28",
+    };
+    if (this.token) {
+      headers.Authorization = `Bearer ${this.token}`;
+    }
+    if (hasBody) {
+      headers["Content-Type"] = "application/json";
+    }
+    return headers;
+  }
+
+  async request(endpoint, options = {}) {
+    const { method = "GET", payload, allow404 = false } = options;
+    const hasBody = payload !== undefined;
+    const url = endpoint.startsWith("http") ? endpoint : `${API_BASE}${endpoint}`;
+    
+    const response = await fetch(url, {
+      method,
+      headers: this.buildHeaders(hasBody),
+      body: hasBody ? JSON.stringify(payload) : undefined,
+    });
+
+    if (allow404 && response.status === 404) {
+      return null;
+    }
+
+    if (!response.ok) {
+      const detail = await response.text();
+      const error = new Error(`GitHub API ${method} ${url} failed: ${response.status} ${detail}`);
+      error.status = response.status;
+      throw error;
+    }
+
+    const text = await response.text();
+    return text ? JSON.parse(text) : null;
+  }
+
+  async getPullRequest() {
+    return this.request(`/repos/${this.repo}/pulls/${this.prNumber}`);
+  }
+
+  async listPrFiles() {
+    const files = [];
+    for (let page = 1; ; page += 1) {
+      const params = new URLSearchParams({ per_page: "100", page: String(page) });
+      const batch = await this.request(`/repos/${this.repo}/pulls/${this.prNumber}/files?${params}`);
+      if (!batch || batch.length === 0) {
+        break;
+      }
+      files.push(...batch);
+      if (batch.length < 100) {
+        break;
+      }
+    }
+    return files;
+  }
+
+  async listIssueLabels() {
+    const labels = await this.request(`/repos/${this.repo}/issues/${this.prNumber}/labels`);
+    return new Set(labels.map((item) => item.name));
+  }
+
+  async syncLabelDefinition(name) {
+    const label = LABEL_DEFINITIONS[name];
+    const createUrl = `/repos/${this.repo}/labels`;
+    const updateUrl = `/repos/${this.repo}/labels/${encodeURIComponent(name)}`;
+
+    try {
+      await this.request(createUrl, {
+        method: "POST",
+        payload: { name, color: label.color, description: label.description },
+      });
+      log(`created label ${name}`);
+    } catch (error) {
+      if (error.status !== 422) {
+        throw error;
+      }
+      await this.request(updateUrl, {
+        method: "PATCH",
+        payload: { new_name: name, color: label.color, description: label.description },
+      });
+      log(`updated label ${name}`);
+    }
+  }
+
+  async addLabels(labels) {
+    if (labels.length === 0) return;
+    await this.request(`/repos/${this.repo}/issues/${this.prNumber}/labels`, {
+      method: "POST",
+      payload: { labels },
+    });
+    log(`added labels: ${labels.join(", ")}`);
+  }
+
+  async removeLabel(name) {
+    await this.request(`/repos/${this.repo}/issues/${this.prNumber}/labels/${encodeURIComponent(name)}`, {
+      method: "DELETE",
+      allow404: true,
+    });
+    log(`removed label: ${name}`);
+  }
+}
+
+// ============================================================================
+// Path & Domain Heuristics
+// ============================================================================
+
+function parsePrType(title) {
+  const match = String(title || "").trim().match(/^([a-z]+)(?:\([^)]+\))?!?:/i);
+  return match ? match[1].toLowerCase() : "";
+}
+
+function isLowRiskPath(filePath) {
+  const normalized = normalizePath(filePath);
+  const basename = path.posix.basename(normalized);
+
+  if (normalized.startsWith("skills/lark-")) return false;
+  if (DOC_SUFFIXES.some((suffix) => normalized.endsWith(suffix))) return true;
+  if (LOW_RISK_FILENAMES.has(basename)) return true;
+  if (LOW_RISK_PREFIXES.some((prefix) => normalized.startsWith(prefix))) return true;
+  if (LOW_RISK_TEST_SUFFIXES.some((suffix) => normalized.endsWith(suffix))) return true;
+  return normalized.includes("/testdata/");
+}
+
+function isBusinessSkillPath(filePath) {
+  const normalized = normalizePath(filePath);
+  return normalized.startsWith("shortcuts/") || normalized.startsWith("skills/lark-");
+}
+
+function shortcutDomainForPath(filePath) {
+  const parts = normalizePath(filePath).split("/");
+  return parts.length >= 2 && parts[0] === "shortcuts" ? parts[1] : "";
+}
+
+function skillDomainForPath(filePath) {
+  const parts = normalizePath(filePath).split("/");
+  return parts.length >= 2 && parts[0] === "skills" && parts[1].startsWith("lark-")
+    ? parts[1].slice("lark-".length)
+    : "";
+}
+
+// Get business domain label based on CODEOWNERS path mapping
+function getBusinessDomain(filePath) {
+  return labelDomainsForPath(filePath)[0] || "";
+}
+
+async function detectNewShortcutDomain(files) {
+  for (const item of files) {
+    if (item.status !== "added") continue;
+    const domain = shortcutDomainForPath(item.filename);
+    if (!domain) continue;
+    try {
+      await fs.access(path.join(ROOT, "shortcuts", domain));
+    } catch {
+      return domain;
+    }
+  }
+  return "";
+}
+
+function collectCoreAreas(filenames) {
+  const areas = new Set();
+  for (const name of filenames) {
+    const normalized = normalizePath(name);
+    for (const prefix of CORE_PREFIXES) {
+      if (normalized.startsWith(prefix)) {
+        // remove trailing slash for area name
+        areas.add(prefix.slice(0, -1));
+      }
+    }
+  }
+  return areas;
+}
+
+function collectSensitiveKeywords(filenames) {
+  const hits = new Set();
+  for (const name of filenames) {
+    const match = normalizePath(name).match(SENSITIVE_PATTERN);
+    if (match && match[2]) {
+      hits.add(match[2]);
+    }
+  }
+  return [...hits].sort();
+}
+
+// ============================================================================
+// Classification Logic
+// ============================================================================
+
+function evaluateRules(context) {
+  const {
+    prType, effectiveChanges, lowRiskOnly,
+    domains, headDomains, coreAreas, coreSignals,
+    sensitiveKeywords, sensitive, newShortcutDomain,
+    singleDomain, multiDomain, filenames
+  } = context;
+
+  const reasons = [];
+  let label;
+
+  if (lowRiskOnly && (LOW_RISK_TYPES.has(prType) || effectiveChanges === 0)) {
+    reasons.push("Only low-risk docs, CI, test, or chore paths were changed, with no effective business code or Skill changes");
+    label = "size/S";
+    return { label, reasons };
+  }
+
+  // XL is reserved for architecture-level or global-impact changes.
+  const isXL =
+    effectiveChanges > THRESHOLD_XL ||
+    (prType === "refactor" && sensitive && effectiveChanges >= THRESHOLD_L) ||
+    (coreAreas.size >= 2 && (multiDomain || effectiveChanges >= THRESHOLD_L)) ||
+    (headDomains.length >= 2 && sensitive);
+
+  if (isXL) {
+    if (effectiveChanges > THRESHOLD_XL) reasons.push("Effective business code or Skill changes are far beyond the L threshold");
+    if (prType === "refactor" && sensitive && effectiveChanges >= THRESHOLD_L) reasons.push("Refactor PR touches core or sensitive paths");
+    if (coreAreas.size >= 2) reasons.push("Touches multiple core areas at the same time");
+    if (headDomains.length >= 2) reasons.push("Impacts multiple major business domains");
+    coreSignals.forEach((signal) => reasons.push(`Core area hit: ${signal}`));
+    sensitiveKeywords.forEach((keyword) => reasons.push(`Sensitive keyword hit: ${keyword}`));
+    label = "size/XL";
+  } else if (
+    prType === "refactor" ||
+    effectiveChanges >= THRESHOLD_L ||
+    Boolean(newShortcutDomain) ||
+    multiDomain ||
+    sensitive
+  ) {
+    if (prType === "refactor") reasons.push("PR type is refactor");
+    if (effectiveChanges >= THRESHOLD_L) reasons.push(`Effective business code or Skill changes exceed ${THRESHOLD_L} lines`);
+    if (newShortcutDomain) reasons.push(`Introduces a new business domain directory: shortcuts/${newShortcutDomain}/`);
+    if (multiDomain) reasons.push("Touches multiple business domains");
+    coreSignals.forEach((signal) => reasons.push(`Core area hit: ${signal}`));
+    sensitiveKeywords.forEach((keyword) => reasons.push(`Sensitive keyword hit: ${keyword}`));
+    label = "size/L";
+  } else {
+    if (filenames.some(isBusinessSkillPath) || effectiveChanges > 0) {
+      reasons.push("Regular feat, fix, or Skill change within a single business domain");
+    }
+    if (singleDomain && domains.size > 0) {
+      reasons.push(`Impact is limited to a single business domain: ${[...domains].sort().join(", ")}`);
+    }
+    if (effectiveChanges < THRESHOLD_L) {
+      reasons.push(`Effective business code or Skill changes are below ${THRESHOLD_L} lines`);
+    }
+    label = "size/M";
+  }
+
+  return { label, reasons };
+}
+
+async function classifyPr(payload, files) {
+  const pr = payload.pull_request;
+  const title = pr.title || "";
+  const prType = parsePrType(title);
+  const filenames = files.map((item) => item.filename || "");
+  const impactedPaths = files.flatMap((item) => {
+    const paths = [item.filename || ""];
+    if (item.status === "renamed" && item.previous_filename) {
+      paths.push(item.previous_filename);
+    }
+    return paths.filter(Boolean);
+  });
+  
+  // Filter out docs, tests, and other low-risk paths so the size label tracks business impact.
+  const effectiveChanges = files.reduce(
+    (sum, item) => sum + (isLowRiskPath(item.filename) ? 0 : (item.changes || 0)),
+    0,
+  );
+  const totalChanges = files.reduce((sum, item) => sum + (item.changes || 0), 0);
+  
+  const domains = new Set();
+  const businessDomains = new Set();
+
+  for (const name of impactedPaths) {
+    const businessDomain = getBusinessDomain(name);
+    if (businessDomain) {
+      businessDomains.add(businessDomain);
+      domains.add(businessDomain);
+      continue;
+    }
+
+    const shortcutDomain = shortcutDomainForPath(name);
+    if (shortcutDomain) domains.add(shortcutDomain);
+
+    const skillDomain = skillDomainForPath(name);
+    if (skillDomain) domains.add(skillDomain);
+  }
+
+  const coreAreas = collectCoreAreas(impactedPaths);
+  const newShortcutDomain = await detectNewShortcutDomain(files);
+  
+  const lowRiskOnly = impactedPaths.length > 0 && impactedPaths.every(isLowRiskPath);
+  const singleDomain = domains.size <= 1;
+  const multiDomain = domains.size >= 2;
+  const headDomains = [...domains].filter((domain) => HEAD_BUSINESS_DOMAINS.has(domain));
+  const coreSignals = [...coreAreas].sort();
+  const sensitiveKeywords = collectSensitiveKeywords(impactedPaths);
+  const sensitive = coreSignals.length > 0 || sensitiveKeywords.length > 0;
+
+  const context = {
+    prType, effectiveChanges, lowRiskOnly,
+    domains, headDomains, coreAreas, coreSignals,
+    sensitiveKeywords, sensitive, newShortcutDomain,
+    singleDomain, multiDomain, filenames: impactedPaths
+  };
+
+  const { label, reasons } = evaluateRules(context);
+
+  return {
+    label,
+    title,
+    prType: prType || "unknown",
+    totalChanges,
+    effectiveChanges,
+    domains: [...domains].sort(),
+    businessDomains: [...businessDomains].sort(),
+    coreAreas: [...coreAreas].sort(),
+    coreSignals,
+    sensitiveKeywords,
+    newShortcutDomain,
+    reasons,
+    lowRiskOnly,
+    filenames,
+  };
+}
+
+// ============================================================================
+// Output & Formatting
+// ============================================================================
+
+async function writeStepSummary(prNumber, classification) {
+  const summaryPath = (process.env.GITHUB_STEP_SUMMARY || "").trim();
+  if (!summaryPath) return;
+
+  const standard = CLASS_STANDARDS[classification.label];
+  const domains = classification.domains.join(", ") || "-";
+  const bDomains = classification.businessDomains.join(", ") || "-";
+  const coreAreas = classification.coreAreas.join(", ") || "-";
+  const reasons = classification.reasons.length > 0
+    ? classification.reasons
+    : ["No higher-severity rule matched, so the PR defaults to medium classification"];
+
+  const lines = [
+    "## PR Size Classification",
+    "",
+    `- PR: #${prNumber}`,
+    `- Label: \`${classification.label}\``,
+    `- PR Type: \`${classification.prType}\``,
+    `- Total Changes: \`${classification.totalChanges}\``,
+    `- Effective Business/SKILL Changes: \`${classification.effectiveChanges}\``,
+    `- Business Domains: \`${domains}\``,
+    `- Impacted Domains: \`${bDomains}\``,
+    `- Core Areas: \`${coreAreas}\``,
+    `- CI/CD Channel: \`${standard.channel}\``,
+    `- Low Risk Only: \`${classification.lowRiskOnly}\``,
+    "",
+    "### Reasons",
+    "",
+    ...reasons.map((reason) => `- ${reason}`),
+    "",
+    "### Pipeline Gates",
+    "",
+    ...standard.gates.map((gate) => `- ${gate}`),
+    "",
+  ];
+
+  await fs.appendFile(summaryPath, `${lines.join("\n")}\n`, "utf8");
+}
+
+function formatDryRunResult(repo, prNumber, classification) {
+  const standard = CLASS_STANDARDS[classification.label];
+  return {
+    repo,
+    prNumber,
+    label: classification.label,
+    prType: classification.prType,
+    totalChanges: classification.totalChanges,
+    effectiveChanges: classification.effectiveChanges,
+    lowRiskOnly: classification.lowRiskOnly,
+    domains: classification.domains,
+    businessDomains: classification.businessDomains,
+    coreAreas: classification.coreAreas,
+    coreSignals: classification.coreSignals,
+    sensitiveKeywords: classification.sensitiveKeywords,
+    reasons: classification.reasons,
+    channel: standard.channel,
+    gates: standard.gates,
+  };
+}
+
+function printDryRunResult(result, options) {
+  if (options.json) {
+    console.log(JSON.stringify(result, null, 2));
+    return;
+  }
+
+  const signalParts = [
+    ...result.coreSignals.map((signal) => `core:${signal}`),
+    ...result.sensitiveKeywords.map((keyword) => `keyword:${keyword}`),
+    ...(result.domains.length > 0 ? [`domains:${result.domains.join(",")}`] : []),
+  ];
+  const reasonParts = result.reasons.length > 0
+    ? result.reasons
+    : ["No higher-severity rule matched, so the PR defaults to medium classification"];
+  
+  console.log(
+    `${result.label} | #${result.prNumber} | type:${result.prType} | eff:${result.effectiveChanges} | `
+      + `sig:${signalParts.join(";") || "-"} | reason:${reasonParts.join("; ")}`,
+  );
+}
+
+function printHelp() {
+  const lines = [
+    "Usage:",
+    "  node scripts/pr-labels/index.js",
+    "  node scripts/pr-labels/index.js --dry-run --pr-url <github-pr-url> [--token <token>] [--json]",
+    "  node scripts/pr-labels/index.js --dry-run --repo <owner/name> --pr-number <number> [--token <token>] [--json]",
+    "",
+    "Modes:",
+    "  default    Read the GitHub Actions event payload and apply labels",
+    "  --dry-run  Fetch the PR, compute the managed label, and print the result without writing labels",
+    "",
+    "Options:",
+    "  --pr-url <url>       GitHub pull request URL, for example https://github.com/larksuite/cli/pull/123",
+    "  --repo <owner/name>  Repository name, used with --pr-number",
+    "  --pr-number <n>      Pull request number, used with --repo",
+    "  --token <token>      GitHub token override; falls back to GITHUB_TOKEN",
+    "  --json               Print dry-run output as JSON instead of the default one-line summary",
+    "  --help               Show this message",
+  ];
+  console.log(lines.join("\n"));
+}
+
+function parseArgs(argv) {
+  const options = {
+    dryRun: false,
+    json: false,
+    help: false,
+    prUrl: "",
+    repo: "",
+    prNumber: "",
+    token: "",
+  };
+
+  for (let i = 0; i < argv.length; i += 1) {
+    const arg = argv[i];
+    if (arg === "--dry-run") options.dryRun = true;
+    else if (arg === "--json") options.json = true;
+    else if (arg === "--help" || arg === "-h") options.help = true;
+    else if (arg === "--pr-url") options.prUrl = argv[++i] || "";
+    else if (arg === "--repo") options.repo = argv[++i] || "";
+    else if (arg === "--pr-number") options.prNumber = argv[++i] || "";
+    else if (arg === "--token") options.token = argv[++i] || "";
+    else throw new Error(`unknown argument: ${arg}`);
+  }
+
+  return options;
+}
+
+function parsePrUrl(prUrl) {
+  let parsed;
+  try {
+    parsed = new URL(prUrl);
+  } catch {
+    throw new Error(`invalid PR URL: ${prUrl}`);
+  }
+
+  const match = parsed.pathname.match(/^\/([^/]+)\/([^/]+)\/pull\/(\d+)\/?$/);
+  if (!match) throw new Error(`unsupported PR URL format: ${prUrl}`);
+
+  return { repo: `${match[1]}/${match[2]}`, prNumber: Number(match[3]) };
+}
+
+async function loadEventPayload(filePath) {
+  return JSON.parse(await fs.readFile(filePath, "utf8"));
+}
+
+async function resolveContext(options) {
+  const token = options.token;
+
+  if (options.prUrl) {
+    const { repo, prNumber } = parsePrUrl(options.prUrl);
+    const client = new GitHubClient(token, repo, prNumber);
+    const payload = {
+      repository: { full_name: repo },
+      pull_request: await client.getPullRequest(),
+    };
+    return { repo, prNumber, payload, client };
+  }
+
+  if (options.repo || options.prNumber) {
+    if (!options.repo || !options.prNumber) throw new Error("--repo and --pr-number must be provided together");
+    const prNumber = Number(options.prNumber);
+    if (!Number.isInteger(prNumber) || prNumber <= 0) throw new Error(`invalid PR number: ${options.prNumber}`);
+    
+    const client = new GitHubClient(token, options.repo, prNumber);
+    const payload = {
+      repository: { full_name: options.repo },
+      pull_request: await client.getPullRequest(),
+    };
+    return { repo: options.repo, prNumber, payload, client };
+  }
+
+  const eventPath = envOrFail("GITHUB_EVENT_PATH");
+  const payload = await loadEventPayload(eventPath);
+  const repo = payload.repository.full_name;
+  const prNumber = payload.pull_request.number;
+  const client = new GitHubClient(token, repo, prNumber);
+
+  return { repo, prNumber, payload, client };
+}
+
+// ============================================================================
+// Main Execution
+// ============================================================================
+
+async function main() {
+  const options = parseArgs(process.argv.slice(2));
+  if (options.help) {
+    printHelp();
+    return;
+  }
+
+  options.token = options.token || envValue("GITHUB_TOKEN");
+
+  if (!options.dryRun && !options.token) {
+    throw new Error("missing required GitHub token; set GITHUB_TOKEN or pass --token");
+  }
+
+  const { repo, prNumber, payload, client } = await resolveContext(options);
+
+  const files = await client.listPrFiles();
+  const classification = await classifyPr(payload, files);
+
+  if (options.dryRun) {
+    printDryRunResult(formatDryRunResult(repo, prNumber, classification), options);
+    return;
+  }
+
+  const desired = new Set([classification.label]);
+  for (const domain of classification.businessDomains) {
+    desired.add(`domain/${domain}`);
+  }
+
+  const current = await client.listIssueLabels();
+  const managedCurrent = [...current].filter((label) => MANAGED_LABELS.has(label) || label.startsWith("domain/"));
+  const toAdd = [...desired].filter((label) => !current.has(label)).sort();
+  const toRemove = managedCurrent.filter((label) => !desired.has(label)).sort();
+
+  for (const domain of classification.businessDomains) {
+    const labelName = `domain/${domain}`;
+    if (!LABEL_DEFINITIONS[labelName]) {
+      LABEL_DEFINITIONS[labelName] = { color: "1d76db", description: `PR touches the ${domain} domain` };
+    }
+  }
+
+  // Ensure labels to be added actually exist in the repository first
+  // If the label doesn't exist, GitHub API will return 422 Unprocessable Entity when trying to add it to a PR.
+  for (const label of toAdd) {
+    if (LABEL_DEFINITIONS[label]) {
+      try {
+        await client.syncLabelDefinition(label);
+      } catch (e) {
+        log(`Warning: Failed to bootstrap new label ${label}: ${e.message}`);
+      }
+    }
+  }
+
+  await client.addLabels(toAdd);
+
+  for (const label of toRemove) {
+    await client.removeLabel(label);
+  }
+
+  // Keep other label metadata consistent. This is best-effort trailing work.
+  for (const label of Object.keys(LABEL_DEFINITIONS)) {
+    if (toAdd.includes(label)) continue; // Already synced above
+    try {
+      await client.syncLabelDefinition(label);
+    } catch (e) {
+      log(`Warning: Failed to sync label definition for ${label}: ${e.message}`);
+    }
+  }
+
+  await writeStepSummary(prNumber, classification);
+
+  log(
+    `pr #${prNumber} type=${classification.prType} total_changes=${classification.totalChanges} `
+      + `effective_changes=${classification.effectiveChanges} files=${files.length} `
+      + `desired=${[...desired].sort().join(",") || "-"} current_managed=${managedCurrent.sort().join(",") || "-"} `
+      + `reasons=${classification.reasons.join(" | ") || "-"}`,
+  );
+}
+
+main().catch((error) => {
+  log(error.message || String(error));
+  process.exit(1);
+});

scripts/pr-labels/samples.json

@@ -0,0 +1,145 @@
+[
+  {
+    "name": "size-s-docs-badge",
+    "number": 103,
+    "title": "docs: add official badge to distinguish from third-party Lark CLI tools",
+    "pr_url": "https://github.com/larksuite/cli/pull/103",
+    "status": "merged",
+    "merged_at": "2026-03-30T12:15:45Z",
+    "expected_label": "size/S",
+    "expected_domains": [],
+    "review_note": "Pure docs sample. Useful to confirm low-risk paths stay in S even when total changed lines are not tiny."
+  },
+  {
+    "name": "size-s-docs-simplify",
+    "number": 26,
+    "title": "docs: simplify installation steps by merging CLI and Skills into one …",
+    "pr_url": "https://github.com/larksuite/cli/pull/26",
+    "status": "merged",
+    "merged_at": "2026-03-28T09:33:24Z",
+    "expected_label": "size/S",
+    "expected_domains": [],
+    "review_note": "Docs sample, verifying docs changes remain in S."
+  },
+  {
+    "name": "size-s-docs-star-history",
+    "number": 12,
+    "title": "docs: add Star History chart to readmes",
+    "pr_url": "https://github.com/larksuite/cli/pull/12",
+    "status": "merged",
+    "merged_at": "2026-03-28T16:00:15Z",
+    "expected_label": "size/S",
+    "expected_domains": [],
+    "review_note": "Docs sample, no effective business code changes."
+  },
+  {
+    "name": "size-s-docs-clarify-install",
+    "number": 3,
+    "title": "docs: clarify install methods and add source build steps",
+    "pr_url": "https://github.com/larksuite/cli/pull/3",
+    "status": "merged",
+    "merged_at": "2026-03-28T03:43:44Z",
+    "expected_label": "size/S",
+    "expected_domains": [],
+    "review_note": "Docs sample, pure documentation clarification."
+  },
+  {
+    "name": "size-m-fix-base-scope",
+    "number": 96,
+    "title": "fix(base): correct scope for record history list shortcut",
+    "pr_url": "https://github.com/larksuite/cli/pull/96",
+    "status": "merged",
+    "merged_at": "2026-03-30T11:40:18Z",
+    "expected_label": "size/M",
+    "expected_domains": ["domain/base"],
+    "review_note": "Small fix sample. Verify the lower edge of the M bucket within a single domain."
+  },
+  {
+    "name": "size-m-fix-mail-sensitive",
+    "number": 92,
+    "title": "fix: remove sensitive send scope from reply and forward shortcuts",
+    "pr_url": "https://github.com/larksuite/cli/pull/92",
+    "status": "merged",
+    "merged_at": "2026-03-30T10:19:11Z",
+    "expected_label": "size/M",
+    "expected_domains": ["domain/mail"],
+    "review_note": "Security-like wording in the title but stays in one business domain (mail)."
+  },
+  {
+    "name": "size-m-ci-improve",
+    "number": 71,
+    "title": "ci: improve CI workflows and add golangci-lint config",
+    "pr_url": "https://github.com/larksuite/cli/pull/71",
+    "status": "merged",
+    "merged_at": "2026-03-30T03:09:31Z",
+    "expected_label": "size/M",
+    "expected_domains": [],
+    "review_note": "CI workflow change that goes beyond S threshold."
+  },
+  {
+    "name": "size-m-feat-im-pagination",
+    "number": 30,
+    "title": "feat: add auto-pagination to messages search and update lark-im docs",
+    "pr_url": "https://github.com/larksuite/cli/pull/30",
+    "status": "merged",
+    "merged_at": "2026-03-30T15:00:41Z",
+    "expected_label": "size/M",
+    "expected_domains": ["domain/im"],
+    "review_note": "Single-domain feature with larger diff but effective changes stay in M."
+  },
+  {
+    "name": "size-l-fix-api-silent",
+    "number": 85,
+    "title": "fix: resolve silent failure in `lark-cli api` error output (#39)",
+    "pr_url": "https://github.com/larksuite/cli/pull/85",
+    "status": "merged",
+    "merged_at": "2026-03-30T09:19:24Z",
+    "expected_label": "size/L",
+    "expected_domains": [],
+    "review_note": "Touches core area (cmd), bumping the size to L."
+  },
+  {
+    "name": "size-l-fix-cli",
+    "number": 91,
+    "title": "fix: correct CLI examples in root help and READMEs (closes #48)",
+    "pr_url": "https://github.com/larksuite/cli/pull/91",
+    "status": "closed",
+    "merged_at": null,
+    "expected_label": "size/L",
+    "expected_domains": [],
+    "review_note": "Closed PR touching core area (cmd)."
+  },
+  {
+    "name": "size-m-skill-format-check",
+    "number": 134,
+    "title": "feat(ci): add skill format check workflow to ensure SKILL.md compliance",
+    "pr_url": "https://github.com/larksuite/cli/pull/134",
+    "status": "closed",
+    "merged_at": null,
+    "expected_label": "size/M",
+    "expected_domains": [],
+    "review_note": "Includes updates to tests/bad-skill/SKILL.md inside skills-like paths, testing how skill mock files and test scripts are handled."
+  },
+  {
+    "name": "size-l-ccm-multi-path",
+    "number": 57,
+    "title": "feat(docs): support local image upload in docs +create",
+    "pr_url": "https://github.com/larksuite/cli/pull/57",
+    "status": "closed",
+    "merged_at": null,
+    "expected_label": "size/L",
+    "expected_domains": ["domain/ccm"],
+    "review_note": "Touches docs_create_images.go and table_auto_width.go, representing multiple CCM sub-paths but resolving to a single ccm domain."
+  },
+  {
+    "name": "size-l-domain-rename",
+    "number": 11,
+    "title": "docs: rename user-facing Bitable references to Base",
+    "pr_url": "https://github.com/larksuite/cli/pull/11",
+    "status": "merged",
+    "merged_at": "2026-03-28T16:00:52Z",
+    "expected_label": "size/L",
+    "expected_domains": ["domain/base", "domain/ccm"],
+    "review_note": "A rename across paths. Since we track previous_filename to evaluate domains, this should properly capture the base domain."
+  }
+]

scripts/pr-labels/test.js

@@ -0,0 +1,55 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+const fs = require('fs');
+const { execFileSync } = require('child_process');
+const path = require('path');
+
+const samplesPath = path.join(__dirname, 'samples.json');
+const indexPath = path.join(__dirname, 'index.js');
+const samples = JSON.parse(fs.readFileSync(samplesPath, 'utf8'));
+
+if (!process.env.GITHUB_TOKEN) {
+  console.error("❌ Error: GITHUB_TOKEN environment variable is required to run tests without hitting API rate limits.");
+  console.error("Please run: GITHUB_TOKEN=$(gh auth token) node scripts/pr-labels/test.js");
+  process.exit(1);
+}
+
+let passed = 0;
+let failed = 0;
+
+for (const sample of samples) {
+  try {
+    const output = execFileSync(
+      process.execPath,
+      [indexPath, '--dry-run', '--json', '--pr-url', sample.pr_url],
+      { encoding: 'utf8', env: process.env }
+    );
+    const result = JSON.parse(output);
+
+    const matchLabel = result.label === sample.expected_label;
+    
+    // Sort before comparing to ignore order
+    const actualDomains = (result.businessDomains || []).sort();
+    const expectedDomains = (sample.expected_domains || []).map(d => d.replace('domain/', '')).sort();
+    
+    const matchDomains = JSON.stringify(actualDomains) === JSON.stringify(expectedDomains);
+
+    if (matchLabel && matchDomains) {
+      console.log(`✅ Passed: ${sample.name}`);
+      passed++;
+    } else {
+      console.log(`❌ Failed: ${sample.name}`);
+      console.log(`   Label expected: ${sample.expected_label}, got: ${result.label}`);
+      console.log(`   Domains expected: ${expectedDomains}, got: ${actualDomains}`);
+      failed++;
+    }
+  } catch (e) {
+    console.log(`❌ Failed: ${sample.name} (Execution error)`);
+    console.error(e.message);
+    failed++;
+  }
+}
+
+console.log(`\nTest Summary: ${passed} passed, ${failed} failed`);
+if (failed > 0) process.exit(1);