// The WHATWG encoder pair, composed: new TextEncoder().encode(s) and
// new TextDecoder().decode(bytes) — utf-8 round trips, BOM stripping, and
// maximal-subpart replacement, byte-compared against Node.
const enc = new TextEncoder().encode("héllo😀");
console.log(enc.length, enc[0], enc[1], enc[2], enc[6]);
console.log(new TextDecoder().decode(enc));

// A leading BOM strips (Buffer.toString("utf8") keeps it — the one
// behavioral difference between the two decodes).
console.log(new TextDecoder().decode(new Uint8Array([0xef, 0xbb, 0xbf, 0x41, 0x42])));
console.log(new TextDecoder().decode(new Uint8Array([0xef, 0xbb, 0xbf])).length);
console.log(Buffer.from([0xef, 0xbb, 0xbf, 0x41]).toString("utf8").length);

// Invalid sequences replace per maximal subpart, exactly like Node.
console.log(JSON.stringify(new TextDecoder().decode(new Uint8Array([0x41, 0xff, 0x42]))));
console.log(JSON.stringify(new TextDecoder().decode(new Uint8Array([0xf0, 0x9f, 0x98]))));

// Zero-argument decode is "" per spec; the explicit utf-8 label works.
console.log(new TextDecoder().decode().length);
console.log(new TextDecoder("utf-8").decode(Buffer.from("hi", "utf8")));

// Round trip through both, Buffer input included.
const rt = new TextDecoder().decode(new TextEncoder().encode("round ✓ trip"));
console.log(rt === "round ✓ trip", rt);
console.log(new TextEncoder().encode("").length);