From 3368a4f4ddcda6e9654b91db89ddca3e3e7a15ec Mon Sep 17 00:00:00 2001
From: Gildas <gildas.lormeau@gmail.com>
Date: Wed, 21 Aug 2024 16:08:25 +0200
Subject: [PATCH] add `offset` option

---
 index.d.ts             | 4 ++++
 lib/core/zip-writer.js | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/index.d.ts b/index.d.ts
index 84de0c57..413cefb7 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1372,6 +1372,10 @@ export interface ZipWriterConstructorOptions {
    * `true` to write encrypted data when `passThrough` is set to `true`.
    */
   encrypted?: boolean;
+  /**
+   * The offset of the first entry in the zip file.
+   */
+  offset?: number;
   /**
    * Encode the filename and the comment of the entry.
    * 
diff --git a/lib/core/zip-writer.js b/lib/core/zip-writer.js
index 2371d87d..cc85bc3b 100644
--- a/lib/core/zip-writer.js
+++ b/lib/core/zip-writer.js
@@ -119,7 +119,7 @@ class ZipWriter {
 			config: getConfiguration(),
 			files: new Map(),
 			filenames: new Set(),
-			offset: writer.writable.size,
+			offset: options.offset === UNDEFINED_VALUE ? writer.writable.size : options.offset,
 			pendingEntriesSize: 0,
 			pendingAddFileCalls: new Set(),
 			bufferedWrites: 0