From 085335ca8736b67db05c02bbd11cccf5b9bf000b Mon Sep 17 00:00:00 2001
From: Vadim Dalecky <streamich@gmail.com>
Date: Thu, 15 Jun 2023 02:18:30 +0200
Subject: [PATCH] =?UTF-8?q?feat:=20=F0=9F=8E=B8=20add=20.truncate()=20meth?=
 =?UTF-8?q?od?=
MIME-Version: 1.0
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---
 src/node-to-fsa/NodeFileSystemSyncAccessHandle.ts    |  8 ++++++++
 .../__tests__/NodeFileSystemSyncAccessHandle.test.ts | 12 ++++++++++++
 src/node-to-fsa/types.ts                             |  2 +-
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/node-to-fsa/NodeFileSystemSyncAccessHandle.ts b/src/node-to-fsa/NodeFileSystemSyncAccessHandle.ts
index 28a90e81e..8dae957a2 100644
--- a/src/node-to-fsa/NodeFileSystemSyncAccessHandle.ts
+++ b/src/node-to-fsa/NodeFileSystemSyncAccessHandle.ts
@@ -55,6 +55,14 @@ export class NodeFileSystemSyncAccessHandle {
       throw error;
     }
   }
+
+  /**
+   * @see https://developer.mozilla.org/en-US/docs/Web/API/FileSystemSyncAccessHandle/truncate
+   * @param newSize The number of bytes to resize the file to.
+   */
+  public async truncate(newSize: number): Promise<void> {
+    this.fs.truncateSync(this.fd, newSize);
+  }
 }
 
 export interface FileSystemReadWriteOptions {
diff --git a/src/node-to-fsa/__tests__/NodeFileSystemSyncAccessHandle.test.ts b/src/node-to-fsa/__tests__/NodeFileSystemSyncAccessHandle.test.ts
index 9db6c161d..a6192a2d0 100644
--- a/src/node-to-fsa/__tests__/NodeFileSystemSyncAccessHandle.test.ts
+++ b/src/node-to-fsa/__tests__/NodeFileSystemSyncAccessHandle.test.ts
@@ -112,4 +112,16 @@ maybe('NodeFileSystemSyncAccessHandle', () => {
       }
     });
   });
+
+  describe('.truncate()', () => {
+    test('can read from beginning', async () => {
+      const { dir } = setup({
+        'file.txt': '0123456789',
+      });
+      const entry = await dir.getFileHandle('file.txt');
+      const sync = await entry.createSyncAccessHandle!();
+      const res = await sync.truncate(5);
+      expect(res).toBe(undefined);
+    });
+  });
 });
diff --git a/src/node-to-fsa/types.ts b/src/node-to-fsa/types.ts
index 950ab9ff7..0d0a058e9 100644
--- a/src/node-to-fsa/types.ts
+++ b/src/node-to-fsa/types.ts
@@ -3,7 +3,7 @@ import type { IFs } from '..';
 /**
  * Required Node.js `fs` module functions for File System Access API.
  */
-export type NodeFsaFs = Pick<IFs, 'promises' | 'openSync' | 'fsyncSync' | 'statSync' | 'closeSync' | 'readSync'>;
+export type NodeFsaFs = Pick<IFs, 'promises' | 'openSync' | 'fsyncSync' | 'statSync' | 'closeSync' | 'readSync' | 'truncateSync'>;
 
 export interface NodeFsaContext {
   separator: '/' | '\\';