fix assertion failure (#2033)

1 files changed, 8 insertions, 0 deletions

diff --git a/test/bun.js/buffer.test.js b/test/bun.js/buffer.test.js
index 37484328b..6c4e9d721 100644
--- a/test/bun.js/buffer.test.js
+++ b/test/bun.js/buffer.test.js
@@ -2525,6 +2525,14 @@ it("should not crash on invalid UTF-8 byte sequence", () => {
   expect(str).toBe("\uFFFD\uFFFD");
 });
 
+it("should not crash on invalid UTF-8 byte sequence with ASCII head", () => {
+  const buf = Buffer.from([0x42, 0xc0, 0xfd]);
+  expect(buf.length).toBe(3);
+  const str = buf.toString();
+  expect(str.length).toBe(3);
+  expect(str).toBe("B\uFFFD\uFFFD");
+});
+
 it("should not perform out-of-bound access on invalid UTF-8 byte sequence", () => {
   const buf = Buffer.from([0x01, 0x9a, 0x84, 0x13, 0x12, 0x11, 0x10, 0x09]).subarray(2);
   expect(buf.length).toBe(6);