From c392d4ce6cd461a480d38fb7332aa40b94718fce Mon Sep 17 00:00:00 2001
From: vini <viniwarrior4@gmail.com>
Date: Thu, 8 Jan 2026 16:56:50 -0300
Subject: [PATCH] feat: add support for FB and Interop JID encoding/decoding
 and empty strings (#2189)

---
 src/WABinary/decode.ts | 27 +++++++++++++++++++++++++++
 src/WABinary/encode.ts |  7 ++++++-
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/WABinary/decode.ts b/src/WABinary/decode.ts
index e8a745c0..b0183d85 100644
--- a/src/WABinary/decode.ts
+++ b/src/WABinary/decode.ts
@@ -167,6 +167,29 @@ export const decodeDecompressedBinaryNode = (
 		return jidEncode(user, server, device)
 	}
 
+	const readFbJid = () => {
+		const user = readString(readByte()!)
+		const device = readInt(2)
+		const server = readString(readByte()!)
+		return `${user}:${device}@${server}`
+	}
+
+	const readInteropJid = () => {
+		const user = readString(readByte()!)
+		const device = readInt(2)
+		const integrator = readInt(2)
+
+		let server = 'interop'
+		const beforeServer = indexRef.index
+		try {
+			server = readString(readByte()!)
+		} catch (err) {
+			indexRef.index = beforeServer
+		}
+
+		return `${integrator}-${user}:${device}@${server}`
+	}
+
 	const readString = (tag: number): string => {
 		if (tag >= 1 && tag < SINGLE_BYTE_TOKENS.length) {
 			return SINGLE_BYTE_TOKENS[tag] || ''
@@ -188,6 +211,10 @@ export const decodeDecompressedBinaryNode = (
 				return readStringFromChars(readInt(4))
 			case TAGS.JID_PAIR:
 				return readJidPair()
+			case TAGS.FB_JID:
+				return readFbJid()
+			case TAGS.INTEROP_JID:
+				return readInteropJid()
 			case TAGS.AD_JID:
 				return readAdJid()
 			case TAGS.HEX_8:
diff --git a/src/WABinary/encode.ts b/src/WABinary/encode.ts
index f8f31ab4..c883e6ed 100644
--- a/src/WABinary/encode.ts
+++ b/src/WABinary/encode.ts
@@ -182,6 +182,11 @@ const encodeBinaryNodeInner = (
 			return
 		}
 
+		if (str === '') {
+			writeStringRaw(str)
+			return
+		}
+
 		const tokenIndex = TOKEN_MAP[str]
 		if (tokenIndex) {
 			if (typeof tokenIndex.dict === 'number') {
@@ -193,7 +198,7 @@ const encodeBinaryNodeInner = (
 			writePackedBytes(str, 'nibble')
 		} else if (isHex(str)) {
 			writePackedBytes(str, 'hex')
-		} else if (str) {
+		} else {
 			const decodedJid = jidDecode(str)
 			if (decodedJid) {
 				writeJid(decodedJid)