fix(zip): handle writePromise rejection from the start

A write-stream error (ENOSPC, EACCES, output path is a directory) can come
while diff or RepackSink is still building entries, long before anyone
awaits writePromise; with no handler attached yet it surfaced as an
unhandled rejection and ended the process before abort() could clean up.
The no-op handler now goes on at creation; awaiting the promise still
rejects.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: sunnylqm

src/utils/zip-entries.ts

@@ -159,9 +159,12 @@ export function createOutputZip(output: string) {
       resolve(void 0);
     });
   });
+  // a write error can come while the caller is still building entries, long
+  // before it awaits writePromise: mark it handled now (awaiting the original
+  // promise still rejects) so it never surfaces as an unhandled rejection
+  writePromise.catch(() => {});
   // 失败时释放输出 fd 并删掉半成品,避免残留一个截断的包
   const abort = async () => {
-    writePromise.catch(() => {});
     zipfile.outputStream.unpipe(writeStream);
     // yazl 的 outputStream 类型声明缺 destroy,运行时是 PassThrough
     (zipfile.outputStream as unknown as { destroy(): void }).destroy();

tests/zip-entries.test.ts

@@ -4,7 +4,7 @@ import os from 'os';
 import path from 'path';
 import { ZipFile } from 'yazl';
 import { removeSync } from '../src/utils/fs-helpers';
-import { enumZipEntries } from '../src/utils/zip-entries';
+import { createOutputZip, enumZipEntries } from '../src/utils/zip-entries';
 
 function zipBuffer(entries: Record<string, Buffer>): Promise<Buffer> {
   const zip = new ZipFile();
@@ -81,3 +81,26 @@ describe('enumZipEntries', () => {
     expect(nestedTempDirs()).toEqual(before);
   });
 });
+
+describe('createOutputZip', () => {
+  test('a write error before writePromise is awaited is not an unhandled rejection', async () => {
+    const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'rnu-output-zip-'));
+    const unhandled: unknown[] = [];
+    const onUnhandled = (reason: unknown) => unhandled.push(reason);
+    process.on('unhandledRejection', onUnhandled);
+    try {
+      // a directory where the zip should go: the write stream fails at once,
+      // while the caller would still be adding entries
+      const output = path.join(dir, 'out.ppk');
+      fs.mkdirSync(output);
+      const { writePromise, abort } = createOutputZip(output);
+      await new Promise((resolve) => setTimeout(resolve, 50));
+      expect(unhandled).toEqual([]);
+      await expect(writePromise).rejects.toMatchObject({ code: 'EISDIR' });
+      await abort();
+    } finally {
+      process.off('unhandledRejection', onUnhandled);
+      removeSync(dir);
+    }
+  });
+});