fix(ext/node/fs): `position` argument not applied (#24009)

We didn't honour the `position` options of `fd.read` and `fd.write`
because we checked if the buffer is of type `Buffer` instead of just
`Uint8Array`. Node does the latter. In doing so I noticed that the file
handle id was written to a public property which it definitely shouldn't
be. This was probably a typo.

Fixes https://github.com/denoland/deno/issues/23707

1 files changed, 24 insertions, 0 deletions

diff --git a/tests/unit_node/_fs/_fs_write_test.ts b/tests/unit_node/_fs/_fs_write_test.ts
index 43bc7a10e..148bc40e7 100644
--- a/tests/unit_node/_fs/_fs_write_test.ts
+++ b/tests/unit_node/_fs/_fs_write_test.ts
@@ -49,3 +49,27 @@ Deno.test({
     assertEquals(decoder.decode(data), "hello");
   },
 });
+
+Deno.test({
+  name: "Data is padded if position > length",
+  async fn() {
+    const tempFile: string = Deno.makeTempFileSync();
+
+    using file = await Deno.open(tempFile, {
+      create: true,
+      write: true,
+      read: true,
+    });
+
+    const str = "hello world";
+    const buffer = Buffer.from(str);
+    const bytesWritten = writeSync(file.rid, buffer, 0, str.length, 4);
+
+    const data = Deno.readFileSync(tempFile);
+    Deno.removeSync(tempFile);
+
+    assertEquals(bytesWritten, str.length);
+    // Check if result is padded
+    assertEquals(decoder.decode(data), "\x00\x00\x00\x00hello world");
+  },
+});