Note that, in the context of bencoding, strings, including dictionary keys, are arbitrary byte sequences (uint8_t[]).
And Array.prototype.sort compares 16-bit units by default.
If compareFn is not supplied, all non-undefined array elements are sorted by converting them to strings and comparing strings in UTF-16 code units order.
The simple .sort() results in a different order (sorted_in_utf16) than the correct one (sorted_in_utf8). Observe:
const A = String.fromCodePoint(0xFF61);
const B = String.fromCodePoint(0x10002);
const sorted_in_utf8 = [A, B].sort((a, b) => Buffer.compare(Buffer.from(a), Buffer.from(b))); // [A, B]
const sorted_in_utf16 = [A, B].sort(); // [B, A]
Bug
https://github.com/webtorrent/node-bencode/blob/2fa2c7ea7d97791a0c7f0cb3dd0bb098c014738f/lib/encode.js#L80-L81
This is not the correct way of sorting dictionary entries.
When you say “strings” in the context of Bencoding, you mean “binary strings,” or more specifically, “8-bit byte sequences.”
And
Array.prototype.sortcompares 16-bit units by default.The simple
.sort()results in a different order (sorted_in_utf16) than the correct one (sorted_in_utf8). Observe:Related issues