Bundle the prebuilt et client at pack time

Download and package the et binaries produced by build-et-binaries:

- resolve-et-bin-release picks the latest et-bin-* release; fetch-et-binaries
  downloads the platform client into resources/et/, verifying SHA256SUMS.
- et-extra-resources emits the electron-builder extraResources entry only
  when the binary is on disk, so pack still works without a bundled et.
- electron-builder.config.cjs wires et into the mac/win/linux bundles;
  package.json adds the fetch:et scripts.

electron-builder.config.cjs

@@ -1,4 +1,5 @@
 const { moshExtraResources } = require('./scripts/mosh-extra-resources.cjs');
+const { etExtraResources } = require('./scripts/et-extra-resources.cjs');
 
 /**
  * @type {import('electron-builder').Configuration}
@@ -98,7 +99,7 @@ module.exports = {
             NSMicrophoneUsageDescription: 'Netcatty may use the microphone for audio',
             NSLocalNetworkUsageDescription: 'Netcatty needs local network access for SSH connections'
         },
-        extraResources: moshExtraResources('darwin')
+        extraResources: [...moshExtraResources('darwin'), ...etExtraResources('darwin')]
     },
     dmg: {
         title: '${productName}',
@@ -125,7 +126,7 @@ module.exports = {
                 arch: ['x64', 'arm64']
             }
         ],
-        extraResources: moshExtraResources('win32')
+        extraResources: [...moshExtraResources('win32'), ...etExtraResources('win32')]
     },
     portable: {
         artifactName: '${productName}-${version}-portable-${os}-${arch}.${ext}',
@@ -146,7 +147,7 @@ module.exports = {
         icon: 'public/icon-win.png',
         target: ['AppImage', 'deb', 'rpm'],
         category: 'Development',
-        extraResources: moshExtraResources('linux')
+        extraResources: [...moshExtraResources('linux'), ...etExtraResources('linux')]
     },
     deb: {
         // Use gzip instead of default xz(lzma) for better compatibility with

package.json

@@ -12,11 +12,13 @@
     "netcatty-tool-cli": "./electron/cli/netcatty-tool-cli.cjs"
   },
   "scripts": {
-    "dev": "npm run fetch:mosh:dev && npm run lint && concurrently -k \"vite\" \"npm:dev:electron\"",
+    "dev": "npm run fetch:mosh:dev && npm run fetch:et:dev && npm run lint && concurrently -k \"vite\" \"npm:dev:electron\"",
     "dev:electron": "wait-on http-get://localhost:5173 && cross-env VITE_DEV_SERVER_URL=http://localhost:5173 node electron/launch.cjs",
     "prebuild": "node scripts/copy-monaco.cjs",
     "fetch:mosh": "node scripts/fetch-mosh-binaries.cjs",
     "fetch:mosh:dev": "node scripts/fetch-mosh-binaries.cjs --host --resolve-release",
+    "fetch:et": "node scripts/fetch-et-binaries.cjs",
+    "fetch:et:dev": "node scripts/fetch-et-binaries.cjs --host --resolve-release",
     "build": "vite build",
     "preview": "vite preview",
     "start": "node electron/launch.cjs",

scripts/et-extra-resources.cjs

@@ -0,0 +1,76 @@
+// Compute the platform-specific `extraResources` entry for bundling the
+// EternalTerminal `et` client. Lives under scripts/ (eslint-ignored) so it
+// can use Node CommonJS globals freely; consumed from
+// electron-builder.config.cjs.
+//
+// Binaries are produced by .github/workflows/build-et-binaries.yml and
+// downloaded into resources/et/<platform-arch>/ by
+// scripts/fetch-et-binaries.cjs (gated on ET_BIN_RELEASE).
+//
+// We only emit the directive when the binary is actually on disk so that
+// `npm run pack` keeps working without a bundled et — for example, when the
+// developer skipped the fetch step or the relevant arch hasn't been built
+// yet.
+//
+// Unlike mosh-client, `et` is a pure network-transport client and does not
+// render a terminal locally, so there is no terminfo bundle to package.
+const fs = require("node:fs");
+const path = require("node:path");
+
+function requestedArch() {
+  return process.env.npm_config_arch || process.env.npm_config_target_arch || process.arch;
+}
+
+function hasFile(file) {
+  return fs.existsSync(file) && fs.statSync(file).isFile();
+}
+
+function hasDir(dir) {
+  return fs.existsSync(dir) && fs.statSync(dir).isDirectory();
+}
+
+function etExtraResources(platform) {
+  const etRoot = path.resolve(process.cwd(), "resources", "et");
+  if (!fs.existsSync(etRoot)) return [];
+
+  if (platform === "darwin") {
+    const file = path.join(etRoot, "darwin-universal", "et");
+    if (!hasFile(file)) return [];
+    return [
+      { from: "resources/et/darwin-universal/", to: "et/", filter: ["et"] },
+    ];
+  }
+
+  if (platform === "linux") {
+    const arch = requestedArch();
+    const file = path.join(etRoot, `linux-${arch}`, "et");
+    if (!hasFile(file)) return [];
+    return [
+      { from: `resources/et/linux-${arch}/`, to: "et/", filter: ["et"] },
+    ];
+  }
+
+  if (platform === "win32") {
+    const arch = requestedArch();
+    const exe = path.join(etRoot, `win32-${arch}`, "et.exe");
+    const dllDir = path.join(etRoot, `win32-${arch}`, `et-win32-${arch}-dlls`);
+    if (!hasFile(exe)) return [];
+    const resources = [
+      { from: `resources/et/win32-${arch}/`, to: "et/", filter: ["et.exe"] },
+    ];
+    // Static MSVC builds ship no DLLs; only package the directory when a
+    // dynamically-linked build produced one.
+    if (hasDir(dllDir)) {
+      resources.push({
+        from: `resources/et/win32-${arch}/et-win32-${arch}-dlls/`,
+        to: `et/et-win32-${arch}-dlls/`,
+        filter: ["**/*"],
+      });
+    }
+    return resources;
+  }
+
+  return [];
+}
+
+module.exports = { etExtraResources };

scripts/et-extra-resources.test.cjs

@@ -0,0 +1,107 @@
+const test = require("node:test");
+const assert = require("node:assert/strict");
+const fs = require("node:fs");
+const os = require("node:os");
+const path = require("node:path");
+
+const { etExtraResources } = require("./et-extra-resources.cjs");
+
+function makeTmp(t) {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), "netcatty-et-resources-"));
+  t.after(() => {
+    if (process.cwd().startsWith(dir)) process.chdir(os.tmpdir());
+    fs.rmSync(dir, { recursive: true, force: true });
+  });
+  return dir;
+}
+
+function withCwdAndArch(t, cwd, arch) {
+  const oldCwd = process.cwd();
+  const oldArch = process.env.npm_config_arch;
+  process.chdir(cwd);
+  process.env.npm_config_arch = arch;
+  t.after(() => {
+    process.chdir(oldCwd);
+    if (oldArch === undefined) delete process.env.npm_config_arch;
+    else process.env.npm_config_arch = oldArch;
+  });
+}
+
+function writeFile(filePath) {
+  fs.mkdirSync(path.dirname(filePath), { recursive: true });
+  fs.writeFileSync(filePath, "x");
+}
+
+test("etExtraResources returns concrete Linux arch paths", (t) => {
+  const root = makeTmp(t);
+  withCwdAndArch(t, root, "x64");
+  writeFile(path.join(root, "resources", "et", "linux-x64", "et"));
+
+  const got = etExtraResources("linux");
+  assert.deepEqual(got, [
+    { from: "resources/et/linux-x64/", to: "et/", filter: ["et"] },
+  ]);
+});
+
+test("etExtraResources returns concrete Linux arm64 paths", (t) => {
+  const root = makeTmp(t);
+  withCwdAndArch(t, root, "arm64");
+  writeFile(path.join(root, "resources", "et", "linux-arm64", "et"));
+
+  const got = etExtraResources("linux");
+  assert.deepEqual(got, [
+    { from: "resources/et/linux-arm64/", to: "et/", filter: ["et"] },
+  ]);
+});
+
+test("etExtraResources packages the universal Darwin binary", (t) => {
+  const root = makeTmp(t);
+  withCwdAndArch(t, root, "x64");
+  writeFile(path.join(root, "resources", "et", "darwin-universal", "et"));
+
+  const got = etExtraResources("darwin");
+  assert.deepEqual(got, [
+    { from: "resources/et/darwin-universal/", to: "et/", filter: ["et"] },
+  ]);
+});
+
+test("etExtraResources returns concrete Windows arch paths only when that arch exists", (t) => {
+  const root = makeTmp(t);
+  withCwdAndArch(t, root, "x64");
+  writeFile(path.join(root, "resources", "et", "win32-x64", "et.exe"));
+
+  const got = etExtraResources("win32");
+  assert.deepEqual(got, [
+    { from: "resources/et/win32-x64/", to: "et/", filter: ["et.exe"] },
+  ]);
+
+  process.env.npm_config_arch = "arm64";
+  assert.deepEqual(etExtraResources("win32"), []);
+});
+
+test("etExtraResources packages an optional Windows DLL directory when present", (t) => {
+  const root = makeTmp(t);
+  withCwdAndArch(t, root, "x64");
+  writeFile(path.join(root, "resources", "et", "win32-x64", "et.exe"));
+  writeFile(path.join(root, "resources", "et", "win32-x64", "et-win32-x64-dlls", "vcruntime140.dll"));
+
+  const got = etExtraResources("win32");
+  assert.deepEqual(got, [
+    { from: "resources/et/win32-x64/", to: "et/", filter: ["et.exe"] },
+    {
+      from: "resources/et/win32-x64/et-win32-x64-dlls/",
+      to: "et/et-win32-x64-dlls/",
+      filter: ["**/*"],
+    },
+  ]);
+});
+
+test("etExtraResources returns [] when the binary is missing", (t) => {
+  const root = makeTmp(t);
+  withCwdAndArch(t, root, "x64");
+  fs.mkdirSync(path.join(root, "resources", "et"), { recursive: true });
+
+  assert.deepEqual(etExtraResources("linux"), []);
+  assert.deepEqual(etExtraResources("darwin"), []);
+  assert.deepEqual(etExtraResources("win32"), []);
+});

scripts/fetch-et-binaries.cjs

@@ -0,0 +1,341 @@
+#!/usr/bin/env node
+/* eslint-disable no-console */
+//
+// Download platform-specific EternalTerminal `et` client binaries built by
+// the `build-et-binaries` GitHub Actions workflow into resources/et/, so
+// electron-builder can bundle them via `extraResources`. Designed to be
+// idempotent and safe to skip in dev / CI matrix legs that don't ship et
+// (e.g. when ET_BIN_RELEASE is unset).
+//
+// Usage:
+//   node scripts/fetch-et-binaries.cjs                # all platforms
+//   node scripts/fetch-et-binaries.cjs --platform=darwin --arch=universal
+//   node scripts/fetch-et-binaries.cjs --host --resolve-release
+//
+// Env knobs:
+//   ET_BIN_RELEASE  — release tag in ${ET_BIN_OWNER}/${ET_BIN_REPO}.
+//                     Skip the whole step if unset (printed as a notice so
+//                     the build doesn't silently miss the bundling).
+//   ET_BIN_OWNER    — defaults to the GITHUB_REPOSITORY owner, or 'binaricat'
+//   ET_BIN_REPO     — default 'Netcatty-et-bin' (a dedicated binary
+//                     repository so the client repo stays source-only).
+//   ET_BIN_BASE_URL — full override (e.g. for staging / local mirror).
+//   ET_BIN_RES_DIR  — override output dir for tests.
+//   ET_BIN_ALLOW_UNVERIFIED=true — explicit local escape hatch for mirrors
+//                     without SHA256SUMS. Never use for release builds.
+
+const fs = require("node:fs");
+const path = require("node:path");
+const http = require("node:http");
+const https = require("node:https");
+const os = require("node:os");
+const crypto = require("node:crypto");
+const { execFileSync } = require("node:child_process");
+const { main: resolveEtBinRelease } = require("./resolve-et-bin-release.cjs");
+
+const ROOT = path.resolve(__dirname, "..");
+const DEFAULT_RES_DIR = path.join(ROOT, "resources", "et");
+
+// (file basename in the release -> platform-arch subdir under resources/et/)
+// Using flat names in the release for SHA256SUMS readability, then fanning
+// out into platform-arch subdirs locally. Every target is a tar.gz bundle
+// containing the single `et` (or `et.exe`) client binary. `et` is a pure
+// network-transport client, so — unlike mosh-client — there is no terminfo
+// to bundle.
+const TARGETS = [
+  { platform: "linux", arch: "x64", file: "et-linux-x64.tar.gz", localDir: "linux-x64", extract: "tar.gz" },
+  { platform: "linux", arch: "arm64", file: "et-linux-arm64.tar.gz", localDir: "linux-arm64", extract: "tar.gz" },
+  { platform: "darwin", arch: "universal", file: "et-darwin-universal.tar.gz", localDir: "darwin-universal", extract: "tar.gz" },
+  { platform: "win32", arch: "x64", file: "et-win32-x64.tar.gz", localDir: "win32-x64", extract: "tar.gz" },
+];
+
+function log(msg) { console.log(`[fetch-et-binaries] ${msg}`); }
+function warn(msg) { console.warn(`[fetch-et-binaries] WARN ${msg}`); }
+
+function transferFor(url) {
+  const protocol = new URL(url).protocol;
+  if (protocol === "https:") return https;
+  if (protocol === "http:") return http;
+  throw new Error(`unsupported protocol for ${url}`);
+}
+
+function follow(url, depth = 0) {
+  return new Promise((resolve, reject) => {
+    if (depth > 5) return reject(new Error("too many redirects"));
+    transferFor(url).get(url, (res) => {
+      if (res.statusCode >= 300 && res.statusCode < 400 && res.headers.location) {
+        res.resume();
+        resolve(follow(new URL(res.headers.location, url).toString(), depth + 1));
+        return;
+      }
+      if (res.statusCode !== 200) {
+        res.resume();
+        reject(new Error(`HTTP ${res.statusCode} for ${url}`));
+        return;
+      }
+      const chunks = [];
+      res.on("data", (c) => chunks.push(c));
+      res.on("end", () => resolve(Buffer.concat(chunks)));
+      res.on("error", reject);
+    }).on("error", reject);
+  });
+}
+
+function parseSums(text) {
+  const map = new Map();
+  for (const line of text.split(/\r?\n/)) {
+    const m = line.match(/^([0-9a-f]{64})\s+\*?\s*(\S+)\s*$/i);
+    if (m) map.set(m[2], m[1].toLowerCase());
+  }
+  return map;
+}
+
+async function fetchSums(baseUrl, { allowUnverified = false } = {}) {
+  try {
+    const buf = await follow(`${baseUrl}/SHA256SUMS`);
+    return parseSums(buf.toString("utf8"));
+  } catch (err) {
+    if (allowUnverified) {
+      warn(`could not fetch SHA256SUMS from ${baseUrl} (${err.message})`);
+      return new Map();
+    }
+    throw new Error(`could not fetch SHA256SUMS from ${baseUrl} (${err.message})`);
+  }
+}
+
+function assertSafeTarEntry(entry) {
+  const name = entry.trim();
+  if (!name) throw new Error("tarball contains an empty entry name");
+  if (name.startsWith("/") || name.startsWith("\\") || /^[A-Za-z]:/.test(name)) {
+    throw new Error(`tarball contains an absolute path: ${name}`);
+  }
+  if (name.includes("\\")) {
+    throw new Error(`tarball contains a Windows-style path: ${name}`);
+  }
+  const parts = name.split("/");
+  if (parts.includes("..")) {
+    throw new Error(`tarball contains a parent-directory path: ${name}`);
+  }
+}
+
+function resolveTarArchiveInvocation(archivePath, platform = process.platform) {
+  const pathApi = platform === "win32" ? path.win32 : path;
+  return {
+    cwd: pathApi.dirname(archivePath),
+    archive: pathApi.basename(archivePath),
+  };
+}
+
+function listTarEntries(archivePath) {
+  const { cwd, archive } = resolveTarArchiveInvocation(archivePath);
+  const out = execFileSync("tar", ["-tzf", archive], { cwd, encoding: "utf8" });
+  return out.split(/\r?\n/).filter(Boolean);
+}
+
+function validateTarEntries(entries) {
+  if (entries.length === 0) throw new Error("tarball is empty");
+  for (const entry of entries) assertSafeTarEntry(entry);
+}
+
+function chmodExecutable(filePath) {
+  if (process.platform !== "win32" && fs.existsSync(filePath) && !fs.lstatSync(filePath).isSymbolicLink()) {
+    try { fs.chmodSync(filePath, 0o755); } catch { /* ignore */ }
+  }
+}
+
+function parseEtBinRepository(env) {
+  const githubOwner = (env.GITHUB_REPOSITORY || "").split("/")[0];
+  return {
+    owner: env.ET_BIN_OWNER || githubOwner || "binaricat",
+    repo: env.ET_BIN_REPO || "Netcatty-et-bin",
+  };
+}
+
+function resolveHostTarget(opts = {}) {
+  const platform = opts.platform || process.platform;
+  const arch = opts.arch || process.arch;
+  if (platform === "darwin") return { platform: "darwin", arch: "universal" };
+  if (platform === "linux" && (arch === "x64" || arch === "arm64")) return { platform, arch };
+  if (platform === "win32" && arch === "x64") return { platform, arch };
+  throw new Error(`No bundled et target for ${platform}-${arch}`);
+}
+
+function assertExtractedTreeSafe(root) {
+  const stack = [root];
+  while (stack.length > 0) {
+    const dir = stack.pop();
+    for (const name of fs.readdirSync(dir)) {
+      const file = path.join(dir, name);
+      const stat = fs.lstatSync(file);
+      if (stat.isSymbolicLink()) {
+        throw new Error(`tarball contains a symbolic link: ${path.relative(root, file)}`);
+      }
+      if (stat.isDirectory()) {
+        stack.push(file);
+        continue;
+      }
+      if (!stat.isFile()) {
+        throw new Error(`tarball contains an unsupported file type: ${path.relative(root, file)}`);
+      }
+    }
+  }
+}
+
+function normalizeWindowsBundle(extractDir, target) {
+  const genericExe = path.join(extractDir, "et.exe");
+  const legacyExe = path.join(extractDir, `et-${target.platform}-${target.arch}.exe`);
+  if (!fs.existsSync(genericExe) && fs.existsSync(legacyExe)) {
+    fs.renameSync(legacyExe, genericExe);
+  }
+  if (!fs.existsSync(genericExe) || !fs.lstatSync(genericExe).isFile()) {
+    throw new Error(`${target.file} did not contain et.exe`);
+  }
+  // A statically-linked MSVC build ships no DLLs; the DLL directory is
+  // optional and only present for dynamically-linked builds.
+  chmodExecutable(genericExe);
+}
+
+function normalizePosixBundle(extractDir, target) {
+  const binary = path.join(extractDir, "et");
+  const legacyBinary = path.join(extractDir, `et-${target.platform}-${target.arch}`);
+  if (!fs.existsSync(binary) && fs.existsSync(legacyBinary)) {
+    fs.renameSync(legacyBinary, binary);
+  }
+  if (!fs.existsSync(binary) || !fs.lstatSync(binary).isFile()) {
+    throw new Error(`${target.file} did not contain et`);
+  }
+  chmodExecutable(binary);
+}
+
+function normalizeBundle(extractDir, target) {
+  if (target.platform === "win32") return normalizeWindowsBundle(extractDir, target);
+  return normalizePosixBundle(extractDir, target);
+}
+
+function replaceDir(srcDir, destDir) {
+  fs.rmSync(destDir, { recursive: true, force: true });
+  fs.mkdirSync(path.dirname(destDir), { recursive: true });
+  try {
+    fs.renameSync(srcDir, destDir);
+  } catch (err) {
+    if (!err || err.code !== "EXDEV") throw err;
+    fs.cpSync(srcDir, destDir, { recursive: true });
+    fs.rmSync(srcDir, { recursive: true, force: true });
+  }
+}
+
+function unpackTarGz(buf, target, { resDir }) {
+  const tmpRoot = fs.mkdtempSync(path.join(os.tmpdir(), "netcatty-et-"));
+  const archive = path.join(tmpRoot, "bundle.tar.gz");
+  const extractDir = path.join(tmpRoot, "extract");
+  const destDir = path.join(resDir, target.localDir);
+  fs.mkdirSync(extractDir, { recursive: true });
+  try {
+    fs.writeFileSync(archive, buf);
+    validateTarEntries(listTarEntries(archive));
+    const archiveInvocation = resolveTarArchiveInvocation(archive);
+    execFileSync("tar", ["-xzf", archiveInvocation.archive, "-C", path.basename(extractDir)], {
+      cwd: archiveInvocation.cwd,
+      stdio: "inherit",
+    });
+    assertExtractedTreeSafe(extractDir);
+    normalizeBundle(extractDir, target);
+    replaceDir(extractDir, destDir);
+  } finally {
+    fs.rmSync(tmpRoot, { recursive: true, force: true });
+  }
+  return destDir;
+}
+
+async function fetchOne(target, sums, opts) {
+  const { baseUrl, resDir, allowUnverified = false } = opts;
+  const url = `${baseUrl}/${target.file}`;
+  let buf;
+  try {
+    buf = await follow(url);
+  } catch (err) {
+    throw new Error(`download failed for ${target.file}: ${err.message}`);
+  }
+
+  const expected = sums.get(target.file);
+  const actual = crypto.createHash("sha256").update(buf).digest("hex");
+  if (expected && expected !== actual) {
+    throw new Error(`SHA256 mismatch for ${target.file}: expected ${expected}, got ${actual}`);
+  }
+  if (!expected) {
+    if (!allowUnverified) {
+      throw new Error(`no SHA256 entry for ${target.file}`);
+    }
+    warn(`no SHA256 entry for ${target.file} - accepting actual ${actual}`);
+  }
+
+  const destDir = unpackTarGz(buf, target, { resDir });
+  log(`unpacked ${target.file} into ${path.relative(ROOT, destDir)}/ (sha256=${actual})`);
+  return true;
+}
+
+async function main(argv = process.argv.slice(2), env = process.env) {
+  const platformArg = (argv.find((a) => a.startsWith("--platform=")) || "").split("=")[1];
+  const archArg = (argv.find((a) => a.startsWith("--arch=")) || "").split("=")[1];
+  let hostTarget = null;
+  if (argv.includes("--host")) {
+    try {
+      hostTarget = resolveHostTarget({ platform: platformArg || process.platform, arch: archArg || process.arch });
+    } catch (err) {
+      warn(`${err.message} - skipping host et fetch.`);
+      return 0;
+    }
+  }
+
+  let release = env.ET_BIN_RELEASE;
+  if (!release && argv.includes("--resolve-release")) {
+    release = await resolveEtBinRelease(env);
+  }
+  if (!release) {
+    log("ET_BIN_RELEASE is unset - skipping. Set it (e.g. et-bin-6.2.10-1) to bundle et into the package.");
+    return 0;
+  }
+
+  const { owner, repo } = parseEtBinRepository(env);
+  const baseUrl = env.ET_BIN_BASE_URL ||
+    `https://github.com/${owner}/${repo}/releases/download/${encodeURIComponent(release)}`;
+  const resDir = path.resolve(env.ET_BIN_RES_DIR || DEFAULT_RES_DIR);
+  const allowUnverified = env.ET_BIN_ALLOW_UNVERIFIED === "true";
+  const platformFilter = hostTarget?.platform || platformArg;
+  const archFilter = hostTarget?.arch || archArg;
+
+  log(`release=${release} owner=${owner} repo=${repo}`);
+  const sums = await fetchSums(baseUrl, { allowUnverified });
+  let ok = 0;
+  let total = 0;
+  for (const target of TARGETS) {
+    if (platformFilter && target.platform !== platformFilter) continue;
+    if (archFilter && target.arch !== archFilter) continue;
+    total += 1;
+    if (await fetchOne(target, sums, { baseUrl, resDir, allowUnverified })) ok += 1;
+  }
+  log(`done - ${ok}/${total} binaries written`);
+  if (ok < total) throw new Error(`only wrote ${ok}/${total} requested binaries`);
+  return 0;
+}
+
+if (require.main === module) {
+  main().catch((err) => {
+    console.error(`[fetch-et-binaries] FATAL ${err.message}`);
+    process.exit(1);
+  });
+}
+
+module.exports = {
+  TARGETS,
+  parseEtBinRepository,
+  replaceDir,
+  resolveHostTarget,
+  resolveTarArchiveInvocation,
+  parseSums,
+  validateTarEntries,
+  assertExtractedTreeSafe,
+  unpackTarGz,
+  normalizeBundle,
+  main,
+};

scripts/fetch-et-binaries.test.cjs

@@ -0,0 +1,278 @@
+const test = require("node:test");
+const assert = require("node:assert/strict");
+const fs = require("node:fs");
+const http = require("node:http");
+const os = require("node:os");
+const path = require("node:path");
+const { execFile, execFileSync } = require("node:child_process");
+const { promisify } = require("node:util");
+const crypto = require("node:crypto");
+
+const script = path.resolve(__dirname, "fetch-et-binaries.cjs");
+const execFileAsync = promisify(execFile);
+const {
+  parseEtBinRepository,
+  replaceDir,
+  resolveHostTarget,
+  resolveTarArchiveInvocation,
+} = require("./fetch-et-binaries.cjs");
+
+function makeTmp(t) {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), "netcatty-fetch-et-"));
+  t.after(() => fs.rmSync(dir, { recursive: true, force: true }));
+  return dir;
+}
+
+function sha256(buf) {
+  return crypto.createHash("sha256").update(buf).digest("hex");
+}
+
+function makeTarGz(t, entries) {
+  const dir = makeTmp(t);
+  for (const [name, contents] of Object.entries(entries)) {
+    const file = path.join(dir, name);
+    fs.mkdirSync(path.dirname(file), { recursive: true });
+    fs.writeFileSync(file, contents);
+  }
+  // Use cwd + a relative archive name so GNU tar (Git Bash on Windows) does
+  // not treat a "C:" drive prefix in the archive path as a remote host.
+  const outDir = makeTmp(t);
+  execFileSync("tar", ["-czf", "bundle.tar.gz", "-C", dir, "."], { cwd: outDir, stdio: "pipe" });
+  return fs.readFileSync(path.join(outDir, "bundle.tar.gz"));
+}
+
+async function serveAssets(t, assets) {
+  const server = http.createServer((req, res) => {
+    const name = decodeURIComponent(req.url.split("/").pop());
+    if (!Object.prototype.hasOwnProperty.call(assets, name)) {
+      res.writeHead(404);
+      res.end("missing");
+      return;
+    }
+    res.writeHead(200);
+    res.end(assets[name]);
+  });
+  await new Promise((resolve) => server.listen(0, "127.0.0.1", resolve));
+  t.after(() => server.close());
+  return `http://127.0.0.1:${server.address().port}`;
+}
+
+test("fetch-et-binaries defaults to the dedicated et binary repository", () => {
+  assert.deepEqual(parseEtBinRepository({}), { owner: "binaricat", repo: "Netcatty-et-bin" });
+  assert.deepEqual(parseEtBinRepository({ GITHUB_REPOSITORY: "owner/project" }), {
+    owner: "owner",
+    repo: "Netcatty-et-bin",
+  });
+  assert.deepEqual(
+    parseEtBinRepository({ GITHUB_REPOSITORY: "owner/project", ET_BIN_OWNER: "bin", ET_BIN_REPO: "binaries" }),
+    { owner: "bin", repo: "binaries" },
+  );
+});
+
+test("resolveHostTarget maps the local platform to the bundled target", () => {
+  assert.deepEqual(resolveHostTarget({ platform: "darwin", arch: "arm64" }), { platform: "darwin", arch: "universal" });
+  assert.deepEqual(resolveHostTarget({ platform: "darwin", arch: "x64" }), { platform: "darwin", arch: "universal" });
+  assert.deepEqual(resolveHostTarget({ platform: "linux", arch: "x64" }), { platform: "linux", arch: "x64" });
+  assert.deepEqual(resolveHostTarget({ platform: "linux", arch: "arm64" }), { platform: "linux", arch: "arm64" });
+  assert.deepEqual(resolveHostTarget({ platform: "win32", arch: "x64" }), { platform: "win32", arch: "x64" });
+  assert.throws(() => resolveHostTarget({ platform: "freebsd", arch: "x64" }), /No bundled et target/);
+});
+
+test("tar archive invocation uses a relative archive name for Windows paths", () => {
+  assert.deepEqual(
+    resolveTarArchiveInvocation(
+      "C:\\Users\\RUNNER~1\\AppData\\Local\\Temp\\netcatty-et-abc\\bundle.tar.gz",
+      "win32",
+    ),
+    {
+      cwd: "C:\\Users\\RUNNER~1\\AppData\\Local\\Temp\\netcatty-et-abc",
+      archive: "bundle.tar.gz",
+    },
+  );
+});
+
+test("replaceDir falls back to copy when rename crosses devices", (t) => {
+  const root = makeTmp(t);
+  const src = path.join(root, "src");
+  const dest = path.join(root, "dest");
+  fs.mkdirSync(src);
+  fs.writeFileSync(path.join(src, "et.exe"), "exe");
+
+  const originalRenameSync = fs.renameSync;
+  fs.renameSync = (from, to) => {
+    if (from === src && to === dest) {
+      const error = new Error("cross-device link not permitted");
+      error.code = "EXDEV";
+      throw error;
+    }
+    return originalRenameSync(from, to);
+  };
+  t.after(() => {
+    fs.renameSync = originalRenameSync;
+  });
+
+  replaceDir(src, dest);
+
+  assert.equal(fs.existsSync(src), false);
+  assert.equal(fs.readFileSync(path.join(dest, "et.exe"), "utf8"), "exe");
+});
+
+test("fetch-et-binaries host mode skips unsupported local targets", async (t) => {
+  const resDir = path.join(makeTmp(t), "resources", "et");
+  const baseUrl = await serveAssets(t, { SHA256SUMS: "" });
+
+  const { stderr } = await execFileAsync(
+    process.execPath,
+    [script, "--host", "--platform=win32", "--arch=arm64"],
+    {
+      env: {
+        ...process.env,
+        ET_BIN_RELEASE: "test",
+        ET_BIN_BASE_URL: baseUrl,
+        ET_BIN_RES_DIR: resDir,
+        CI: "true",
+      },
+      stdio: "pipe",
+    },
+  );
+
+  assert.match(stderr, /No bundled et target for win32-arm64/);
+  assert.equal(fs.existsSync(resDir), false);
+});
+
+test("fetch-et-binaries skips when ET_BIN_RELEASE is unset", async (t) => {
+  const resDir = path.join(makeTmp(t), "resources", "et");
+  const { stdout } = await execFileAsync(process.execPath, [script], {
+    env: { ...process.env, ET_BIN_RELEASE: "", ET_BIN_RES_DIR: resDir, CI: "true" },
+    stdio: "pipe",
+  });
+  assert.match(stdout, /ET_BIN_RELEASE is unset/);
+  assert.equal(fs.existsSync(resDir), false);
+});
+
+test("fetch-et-binaries unpacks the Linux tarball", async (t) => {
+  const resDir = path.join(makeTmp(t), "resources", "et");
+  const tar = makeTarGz(t, { et: "binary" });
+  const baseUrl = await serveAssets(t, {
+    "et-linux-x64.tar.gz": tar,
+    SHA256SUMS: `${sha256(tar)}  et-linux-x64.tar.gz\n`,
+  });
+
+  await execFileAsync(process.execPath, [script, "--platform=linux", "--arch=x64"], {
+    env: { ...process.env, ET_BIN_RELEASE: "test", ET_BIN_BASE_URL: baseUrl, ET_BIN_RES_DIR: resDir, CI: "true" },
+    stdio: "pipe",
+  });
+
+  assert.equal(fs.existsSync(path.join(resDir, "linux-x64", "et")), true);
+  assert.equal(fs.readFileSync(path.join(resDir, "linux-x64", "et"), "utf8"), "binary");
+});
+
+test("fetch-et-binaries unpacks the Darwin universal tarball", async (t) => {
+  const resDir = path.join(makeTmp(t), "resources", "et");
+  const tar = makeTarGz(t, { et: "binary" });
+  const baseUrl = await serveAssets(t, {
+    "et-darwin-universal.tar.gz": tar,
+    SHA256SUMS: `${sha256(tar)}  et-darwin-universal.tar.gz\n`,
+  });
+
+  await execFileAsync(process.execPath, [script, "--platform=darwin", "--arch=universal"], {
+    env: { ...process.env, ET_BIN_RELEASE: "test", ET_BIN_BASE_URL: baseUrl, ET_BIN_RES_DIR: resDir, CI: "true" },
+    stdio: "pipe",
+  });
+
+  assert.equal(fs.existsSync(path.join(resDir, "darwin-universal", "et")), true);
+});
+
+test("fetch-et-binaries normalizes a static Windows tarball with no DLLs", async (t) => {
+  const resDir = path.join(makeTmp(t), "resources", "et");
+  const tar = makeTarGz(t, { "et.exe": "exe" });
+  const baseUrl = await serveAssets(t, {
+    "et-win32-x64.tar.gz": tar,
+    SHA256SUMS: `${sha256(tar)}  et-win32-x64.tar.gz\n`,
+  });
+
+  await execFileAsync(process.execPath, [script, "--platform=win32", "--arch=x64"], {
+    env: { ...process.env, ET_BIN_RELEASE: "test", ET_BIN_BASE_URL: baseUrl, ET_BIN_RES_DIR: resDir, CI: "true" },
+    stdio: "pipe",
+  });
+
+  assert.equal(fs.existsSync(path.join(resDir, "win32-x64", "et.exe")), true);
+});
+
+test("fetch-et-binaries packages an optional Windows DLL directory when present", async (t) => {
+  const resDir = path.join(makeTmp(t), "resources", "et");
+  const tar = makeTarGz(t, { "et.exe": "exe", "et-win32-x64-dlls/vcruntime140.dll": "dll" });
+  const baseUrl = await serveAssets(t, {
+    "et-win32-x64.tar.gz": tar,
+    SHA256SUMS: `${sha256(tar)}  et-win32-x64.tar.gz\n`,
+  });
+
+  await execFileAsync(process.execPath, [script, "--platform=win32", "--arch=x64"], {
+    env: { ...process.env, ET_BIN_RELEASE: "test", ET_BIN_BASE_URL: baseUrl, ET_BIN_RES_DIR: resDir, CI: "true" },
+    stdio: "pipe",
+  });
+
+  assert.equal(fs.existsSync(path.join(resDir, "win32-x64", "et.exe")), true);
+  assert.equal(fs.existsSync(path.join(resDir, "win32-x64", "et-win32-x64-dlls", "vcruntime140.dll")), true);
+});
+
+test("fetch-et-binaries rejects a tarball without et", async (t) => {
+  const resDir = path.join(makeTmp(t), "resources", "et");
+  const tar = makeTarGz(t, { "readme.txt": "nope" });
+  const baseUrl = await serveAssets(t, {
+    "et-linux-x64.tar.gz": tar,
+    SHA256SUMS: `${sha256(tar)}  et-linux-x64.tar.gz\n`,
+  });
+
+  await assert.rejects(
+    execFileAsync(process.execPath, [script, "--platform=linux", "--arch=x64"], {
+      env: { ...process.env, ET_BIN_RELEASE: "test", ET_BIN_BASE_URL: baseUrl, ET_BIN_RES_DIR: resDir, CI: "true" },
+      stdio: "pipe",
+    }),
+    /did not contain et/,
+  );
+});
+
+test("fetch-et-binaries fails when SHA256SUMS lacks the requested asset", async (t) => {
+  const resDir = path.join(makeTmp(t), "resources", "et");
+  const tar = makeTarGz(t, { et: "binary" });
+  const baseUrl = await serveAssets(t, {
+    "et-linux-x64.tar.gz": tar,
+    SHA256SUMS: `${sha256(Buffer.from("other"))}  other-file\n`,
+  });
+
+  await assert.rejects(
+    execFileAsync(process.execPath, [script, "--platform=linux", "--arch=x64"], {
+      env: { ...process.env, ET_BIN_RELEASE: "test", ET_BIN_BASE_URL: baseUrl, ET_BIN_RES_DIR: resDir, CI: "true" },
+      stdio: "pipe",
+    }),
+    /no SHA256 entry/,
+  );
+});
+
+test("fetch-et-binaries rejects symlinks inside tarballs", { skip: process.platform === "win32" }, async (t) => {
+  const srcDir = makeTmp(t);
+  fs.writeFileSync(path.join(srcDir, "outside"), "outside");
+  fs.symlinkSync(path.join(srcDir, "outside"), path.join(srcDir, "et"));
+  const outDir = makeTmp(t);
+  execFileSync("tar", ["-czf", "symlink.tar.gz", "-C", srcDir, "et"], { cwd: outDir, stdio: "pipe" });
+  const tar = fs.readFileSync(path.join(outDir, "symlink.tar.gz"));
+  const baseUrl = await serveAssets(t, {
+    "et-linux-x64.tar.gz": tar,
+    SHA256SUMS: `${sha256(tar)}  et-linux-x64.tar.gz\n`,
+  });
+
+  await assert.rejects(
+    execFileAsync(process.execPath, [script, "--platform=linux", "--arch=x64"], {
+      env: {
+        ...process.env,
+        ET_BIN_RELEASE: "test",
+        ET_BIN_BASE_URL: baseUrl,
+        ET_BIN_RES_DIR: path.join(makeTmp(t), "resources", "et"),
+        CI: "true",
+      },
+      stdio: "pipe",
+    }),
+    /symbolic link|did not contain et/,
+  );
+});

scripts/resolve-et-bin-release.cjs

@@ -0,0 +1,187 @@
+#!/usr/bin/env node
+/* eslint-disable no-console */
+//
+// Resolve the EternalTerminal `et` client binary release used by
+// build-packages.
+//
+// Priority:
+//   1. ET_BIN_RELEASE from workflow input / repository variable.
+//   2. Latest non-draft, non-prerelease GitHub Release whose tag is
+//      et-bin-* in ET_BIN_OWNER/ET_BIN_REPO. By default this is a
+//      dedicated sibling binary repository named Netcatty-et-bin.
+//
+// In GitHub Actions, the resolved tag is written back to $GITHUB_ENV so
+// later steps can run scripts/fetch-et-binaries.cjs without duplicating
+// release discovery logic.
+
+const fs = require("node:fs");
+const https = require("node:https");
+
+const TAG_RE = /^et-bin-[A-Za-z0-9._-]+$/;
+
+function log(msg) {
+  console.log(`[resolve-et-bin-release] ${msg}`);
+}
+
+function validateReleaseTag(tag) {
+  const value = String(tag || "").trim();
+  if (!TAG_RE.test(value)) {
+    throw new Error(`invalid et binary release tag: ${tag}`);
+  }
+  return value;
+}
+
+function parseRepository(env) {
+  const owner = env.ET_BIN_OWNER || (env.GITHUB_REPOSITORY || "").split("/")[0] || "binaricat";
+  const repo = env.ET_BIN_REPO || "Netcatty-et-bin";
+  return { owner, repo };
+}
+
+function releaseTimestamp(release) {
+  const raw = release.published_at || release.created_at || "";
+  const value = Date.parse(raw);
+  return Number.isNaN(value) ? 0 : value;
+}
+
+function pickLatestEtBinRelease(releases) {
+  return releases
+    .map((release, index) => ({ release, index }))
+    .filter(({ release }) => {
+      return release
+        && TAG_RE.test(String(release.tag_name || ""))
+        && release.draft !== true
+        && release.prerelease !== true;
+    })
+    .sort((a, b) => {
+      const diff = releaseTimestamp(b.release) - releaseTimestamp(a.release);
+      return diff || a.index - b.index;
+    })[0]?.release.tag_name;
+}
+
+function parseNextLink(linkHeader) {
+  if (!linkHeader) return null;
+  for (const part of String(linkHeader).split(",")) {
+    const match = part.match(/^\s*<([^>]+)>\s*;\s*(.+)\s*$/);
+    if (!match) continue;
+    const rel = match[2].split(";").some((attr) => attr.trim() === 'rel="next"');
+    if (rel) return match[1];
+  }
+  return null;
+}
+
+function requestJsonWithHeaders(url, env, depth = 0) {
+  return new Promise((resolve, reject) => {
+    if (depth > 5) {
+      reject(new Error("too many redirects while looking up et binary releases"));
+      return;
+    }
+
+    const headers = {
+      Accept: "application/vnd.github+json",
+      "User-Agent": "netcatty-et-release-resolver",
+      "X-GitHub-Api-Version": "2022-11-28",
+    };
+    const token = env.GITHUB_TOKEN || env.GH_TOKEN;
+    if (token) headers.Authorization = `Bearer ${token}`;
+
+    https.get(url, { headers }, (res) => {
+      const location = res.headers.location;
+      if (res.statusCode >= 300 && res.statusCode < 400 && location) {
+        res.resume();
+        resolve(requestJsonWithHeaders(new URL(location, url).toString(), env, depth + 1));
+        return;
+      }
+
+      const chunks = [];
+      res.on("data", (chunk) => chunks.push(chunk));
+      res.on("end", () => {
+        const body = Buffer.concat(chunks).toString("utf8");
+        if (res.statusCode !== 200) {
+          reject(new Error(`GitHub API returned HTTP ${res.statusCode}: ${body.slice(0, 300)}`));
+          return;
+        }
+        try {
+          resolve({ json: JSON.parse(body), headers: res.headers });
+        } catch (err) {
+          reject(new Error(`GitHub API returned invalid JSON: ${err.message}`));
+        }
+      });
+      res.on("error", reject);
+    }).on("error", reject);
+  });
+}
+
+async function loadReleases(env, request = requestJsonWithHeaders) {
+  if (env.ET_BIN_RELEASES_JSON) {
+    const parsed = JSON.parse(env.ET_BIN_RELEASES_JSON);
+    if (!Array.isArray(parsed)) {
+      throw new Error("ET_BIN_RELEASES_JSON must be a JSON array");
+    }
+    return parsed;
+  }
+
+  const { owner, repo } = parseRepository(env);
+  const apiBase = (env.GITHUB_API_URL || "https://api.github.com").replace(/\/+$/, "");
+  let url = `${apiBase}/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/releases?per_page=100`;
+  log(`looking up latest et-bin-* release in ${owner}/${repo}`);
+  const releases = [];
+  const seen = new Set();
+  while (url) {
+    if (seen.has(url)) {
+      throw new Error(`GitHub API pagination looped while looking up releases: ${url}`);
+    }
+    seen.add(url);
+
+    const { json, headers = {} } = await request(url, env);
+    if (!Array.isArray(json)) {
+      throw new Error("GitHub API releases response was not an array");
+    }
+    releases.push(...json);
+    url = parseNextLink(headers.link);
+  }
+  return releases;
+}
+
+function exportRelease(release, env) {
+  if (env.GITHUB_ENV) {
+    fs.appendFileSync(env.GITHUB_ENV, `ET_BIN_RELEASE=${release}\n`, "utf8");
+  }
+}
+
+async function main(env = process.env) {
+  if (String(env.ET_BIN_RELEASE || "").trim()) {
+    const release = validateReleaseTag(env.ET_BIN_RELEASE);
+    exportRelease(release, env);
+    log(`using ET_BIN_RELEASE=${release}`);
+    return release;
+  }
+
+  const releases = await loadReleases(env);
+  const release = pickLatestEtBinRelease(releases);
+  if (!release) {
+    throw new Error(
+      "could not find a non-draft et-bin-* release in the et binary repository. Publish build-et-binaries artifacts with release_tag (for example et-bin-6.2.10-1) before packaging.",
+    );
+  }
+
+  const validated = validateReleaseTag(release);
+  exportRelease(validated, env);
+  log(`resolved ET_BIN_RELEASE=${validated}`);
+  return validated;
+}
+
+if (require.main === module) {
+  main().catch((err) => {
+    console.error(`[resolve-et-bin-release] FATAL ${err.message}`);
+    process.exit(1);
+  });
+}
+
+module.exports = {
+  loadReleases,
+  parseNextLink,
+  validateReleaseTag,
+  parseRepository,
+  pickLatestEtBinRelease,
+  main,
+};

scripts/resolve-et-bin-release.test.cjs

@@ -0,0 +1,134 @@
+const test = require("node:test");
+const assert = require("node:assert/strict");
+const fs = require("node:fs");
+const os = require("node:os");
+const path = require("node:path");
+
+const {
+  loadReleases,
+  main,
+  parseRepository,
+  parseNextLink,
+  pickLatestEtBinRelease,
+  validateReleaseTag,
+} = require("./resolve-et-bin-release.cjs");
+
+function makeTmp(t) {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), "netcatty-resolve-et-"));
+  t.after(() => fs.rmSync(dir, { recursive: true, force: true }));
+  return dir;
+}
+
+test("validateReleaseTag accepts only et binary release tags", () => {
+  assert.equal(validateReleaseTag("et-bin-6.2.10-1"), "et-bin-6.2.10-1");
+  assert.throws(() => validateReleaseTag("v1.2.3"), /invalid et binary release tag/);
+  assert.throws(() => validateReleaseTag("et-bin-../bad"), /invalid et binary release tag/);
+});
+
+test("parseRepository falls back to the dedicated et binary repository", () => {
+  assert.deepEqual(parseRepository({}), { owner: "binaricat", repo: "Netcatty-et-bin" });
+  assert.deepEqual(parseRepository({ GITHUB_REPOSITORY: "owner/project" }), {
+    owner: "owner",
+    repo: "Netcatty-et-bin",
+  });
+  assert.deepEqual(
+    parseRepository({ GITHUB_REPOSITORY: "owner/project", ET_BIN_OWNER: "bin", ET_BIN_REPO: "binaries" }),
+    { owner: "bin", repo: "binaries" },
+  );
+});
+
+test("pickLatestEtBinRelease ignores non-packaging releases", () => {
+  const got = pickLatestEtBinRelease([
+    { tag_name: "v1.0.0", published_at: "2026-03-01T00:00:00Z" },
+    { tag_name: "et-bin-6.2.10-3", draft: true, published_at: "2026-04-01T00:00:00Z" },
+    { tag_name: "et-bin-6.2.10-4", prerelease: true, published_at: "2026-04-02T00:00:00Z" },
+    { tag_name: "et-bin-6.2.10-1", published_at: "2026-02-01T00:00:00Z" },
+    { tag_name: "et-bin-6.2.10-2", published_at: "2026-03-01T00:00:00Z" },
+  ]);
+
+  assert.equal(got, "et-bin-6.2.10-2");
+});
+
+test("parseNextLink reads the next GitHub pagination URL", () => {
+  const link = [
+    '<https://api.github.com/repos/owner/repo/releases?per_page=100&page=1>; rel="prev"',
+    '<https://api.github.com/repos/owner/repo/releases?per_page=100&page=3>; rel="next"',
+    '<https://api.github.com/repos/owner/repo/releases?per_page=100&page=9>; rel="last"',
+  ].join(", ");
+
+  assert.equal(
+    parseNextLink(link),
+    "https://api.github.com/repos/owner/repo/releases?per_page=100&page=3",
+  );
+  assert.equal(parseNextLink('<https://api.github.com/repos/owner/repo/releases?page=1>; rel="last"'), null);
+});
+
+test("loadReleases follows GitHub pagination until the last page", async () => {
+  const requested = [];
+  const got = await loadReleases({ GITHUB_REPOSITORY: "owner/repo" }, async (url) => {
+    requested.push(url);
+    if (url.includes("page=2")) {
+      return {
+        json: [{ tag_name: "et-bin-6.2.10-1", published_at: "2026-01-01T00:00:00Z" }],
+        headers: {},
+      };
+    }
+    return {
+      json: [{ tag_name: "v1.0.0", published_at: "2026-01-01T00:00:00Z" }],
+      headers: {
+        link: '<https://api.github.com/repos/owner/repo/releases?per_page=100&page=2>; rel="next"',
+      },
+    };
+  });
+
+  assert.deepEqual(got.map((release) => release.tag_name), ["v1.0.0", "et-bin-6.2.10-1"]);
+  assert.equal(requested.length, 2);
+});
+
+test("loadReleases rejects pagination loops", async () => {
+  await assert.rejects(
+    loadReleases({ GITHUB_REPOSITORY: "owner/repo" }, async (url) => ({
+      json: [],
+      headers: { link: `<${url}>; rel="next"` },
+    })),
+    /pagination looped/,
+  );
+});
+
+test("main keeps an explicit ET_BIN_RELEASE and exports it", async (t) => {
+  const githubEnv = path.join(makeTmp(t), "github-env");
+
+  const got = await main({
+    ET_BIN_RELEASE: "et-bin-6.2.10-1",
+    GITHUB_ENV: githubEnv,
+  });
+
+  assert.equal(got, "et-bin-6.2.10-1");
+  assert.equal(fs.readFileSync(githubEnv, "utf8"), "ET_BIN_RELEASE=et-bin-6.2.10-1\n");
+});
+
+test("main resolves the latest release from the release list and exports it", async (t) => {
+  const githubEnv = path.join(makeTmp(t), "github-env");
+  const got = await main({
+    GITHUB_ENV: githubEnv,
+    ET_BIN_RELEASES_JSON: JSON.stringify([
+      { tag_name: "et-bin-6.2.10-1", published_at: "2026-01-01T00:00:00Z" },
+      { tag_name: "et-bin-6.2.10-2", published_at: "2026-02-01T00:00:00Z" },
+    ]),
+  });
+
+  assert.equal(got, "et-bin-6.2.10-2");
+  assert.equal(fs.readFileSync(githubEnv, "utf8"), "ET_BIN_RELEASE=et-bin-6.2.10-2\n");
+});
+
+test("main fails when no usable release exists", async () => {
+  await assert.rejects(
+    main({
+      ET_BIN_RELEASES_JSON: JSON.stringify([
+        { tag_name: "v1.0.0", published_at: "2026-01-01T00:00:00Z" },
+        { tag_name: "et-bin-6.2.10-1", draft: true, published_at: "2026-02-01T00:00:00Z" },
+      ]),
+    }),
+    /could not find/,
+  );
+});