fix(cli): Buffer.bytes() ArrayBuffer size (#6511)

2 files changed, 14 insertions, 1 deletions

diff --git a/cli/js/buffer.ts b/cli/js/buffer.ts
index 473affe3d..6a5105908 100644
--- a/cli/js/buffer.ts
+++ b/cli/js/buffer.ts
@@ -40,7 +40,7 @@ export class Buffer implements Reader, ReaderSync, Writer, WriterSync {
   }
 
   bytes(): Uint8Array {
-    return this.#buf.subarray(this.#off);
+    return this.#buf.slice(this.#off);
   }
 
   empty(): boolean {
diff --git a/cli/tests/unit/buffer_test.ts b/cli/tests/unit/buffer_test.ts
index 644f05952..dc80c9c6d 100644
--- a/cli/tests/unit/buffer_test.ts
+++ b/cli/tests/unit/buffer_test.ts
@@ -298,3 +298,16 @@ unitTest(function testWriteAllSync(): void {
     assertEquals(testBytes[i], actualBytes[i]);
   }
 });
+
+unitTest(function testBufferBytesArrayBufferLength(): void {
+  const bytes = new TextEncoder().encode("a");
+  const reader = new Deno.Buffer();
+  Deno.writeAllSync(reader, bytes);
+
+  const writer = new Deno.Buffer();
+  writer.readFromSync(reader);
+  const actualBytes = writer.bytes();
+
+  assertEquals(bytes.byteLength, 1);
+  assertEquals(bytes.byteLength, actualBytes.buffer.byteLength);
+});