fix: build Windows exe from Windows node binary on non-Windows CI

scripts/build-win.js

@@ -1,3 +1,4 @@
+const crypto = require('crypto');
 const fs = require('fs');
 const os = require('os');
 const path = require('path');
@@ -10,6 +11,39 @@ function normalizeBuildVersion(value) {
   return version.startsWith('v') ? version : `v${version}`;
 }
 
+async function download(url) {
+  const response = await fetch(url);
+  if (!response.ok) {
+    throw new Error(`Failed to download ${url}: ${response.status} ${response.statusText}`);
+  }
+  return Buffer.from(await response.arrayBuffer());
+}
+
+// SEA blobs must be injected into a node binary of the same version, and non-Windows hosts need a Windows base binary.
+async function getWindowsNodeBinary(tempDir) {
+  if (process.platform === 'win32') {
+    return process.execPath;
+  }
+
+  const baseUrl = `https://nodejs.org/dist/${process.version}`;
+  const [binary, shasums] = await Promise.all([
+    download(`${baseUrl}/win-x64/node.exe`),
+    download(`${baseUrl}/SHASUMS256.txt`),
+  ]);
+
+  const expected = shasums.toString('utf8').split('\n')
+    .map(line => line.trim().split(/\s+/))
+    .find(([, file]) => file === 'win-x64/node.exe');
+  const actual = crypto.createHash('sha256').update(binary).digest('hex');
+  if (!expected || expected[0] !== actual) {
+    throw new Error('Checksum verification failed for downloaded win-x64/node.exe');
+  }
+
+  const binaryPath = path.join(tempDir, 'node.exe');
+  fs.writeFileSync(binaryPath, binary);
+  return binaryPath;
+}
+
 async function main() {
   const distDir = path.resolve(__dirname, '..', 'dist');
   if (!fs.existsSync(distDir)) {
@@ -33,8 +67,11 @@ async function main() {
     logLevel: 'info',
   });
 
+  const executable = await getWindowsNodeBinary(tempDir);
+
   fs.writeFileSync(seaConfigPath, JSON.stringify({
     main: bundlePath,
+    executable,
     output: outputFile,
     mainFormat: 'commonjs',
     disableExperimentalSEAWarning: true,
@@ -43,6 +80,14 @@ async function main() {
   }, null, 2));
 
   execFileSync(process.execPath, ['--build-sea', seaConfigPath], {stdio: 'inherit'});
+
+  const header = Buffer.alloc(2);
+  const fd = fs.openSync(outputFile, 'r');
+  fs.readSync(fd, header, 0, 2, 0);
+  fs.closeSync(fd);
+  if (header.toString('latin1') !== 'MZ') {
+    throw new Error(`${outputFile} is not a Windows PE executable`);
+  }
 }
 
 main().catch(error => {