fix: store LID-PN mapping from contactAction sync (#2266)

* fix: store LID-PN mapping from contactAction sync

* chore: improve testing of sync actions

src/Utils/chat-utils.ts

@@ -24,6 +24,7 @@ import { toNumber } from './generics'
 import type { ILogger } from './logger'
 import { LT_HASH_ANTI_TAMPERING } from './lt-hash'
 import { downloadContentFromMessage } from './messages-media'
+import { emitSyncActionResults, processContactAction } from './sync-action-utils'
 
 type FetchAppStateSyncKey = (keyId: string) => Promise<proto.Message.IAppStateSyncKeyData | null | undefined>
 
@@ -832,14 +833,8 @@ export const processSyncAction = (
 			]
 		})
 	} else if (action?.contactAction) {
-		ev.emit('contacts.upsert', [
-			{
-				id: id!,
-				name: action.contactAction.fullName!,
-				lid: action.contactAction.lidJid || undefined,
-				phoneNumber: action.contactAction.pnJid || undefined
-			}
-		])
+		const results = processContactAction(action.contactAction, id, logger)
+		emitSyncActionResults(ev, results)
 	} else if (action?.pushNameSetting) {
 		const name = action?.pushNameSetting?.name
 		if (name && me?.name !== name) {
@@ -935,7 +930,7 @@ export const processSyncAction = (
 		ev.emit('contacts.upsert', [
 			{
 				id: id!,
-				name: action.lidContactAction.fullName!,
+				name: action.lidContactAction.fullName || undefined,
 				lid: id!,
 				phoneNumber: undefined
 			}

src/Utils/sync-action-utils.ts

@@ -0,0 +1,74 @@
+import { proto } from '../../WAProto/index.js'
+import type { BaileysEventEmitter, BaileysEventMap, Contact } from '../Types'
+import { isLidUser, isPnUser } from '../WABinary'
+import type { ILogger } from './logger'
+
+export type ContactsUpsertResult = {
+	event: 'contacts.upsert'
+	data: Contact[]
+}
+
+export type LidMappingUpdateResult = {
+	event: 'lid-mapping.update'
+	data: BaileysEventMap['lid-mapping.update']
+}
+
+export type SyncActionResult = ContactsUpsertResult | LidMappingUpdateResult
+
+/**
+ * Process contactAction and return events to emit.
+ * Pure function - no side effects.
+ */
+export const processContactAction = (
+	action: proto.SyncActionValue.IContactAction,
+	id: string | undefined,
+	logger?: ILogger
+): SyncActionResult[] => {
+	const results: SyncActionResult[] = []
+
+	if (!id) {
+		logger?.warn(
+			{ hasFullName: !!action.fullName, hasLidJid: !!action.lidJid, hasPnJid: !!action.pnJid },
+			'contactAction sync: missing id in index'
+		)
+		return results
+	}
+
+	const lidJid = action.lidJid
+	const idIsPn = isPnUser(id)
+	// PN is in index[1], not in contactAction.pnJid which is usually null
+	const phoneNumber = idIsPn ? id : action.pnJid || undefined
+
+	// Always emit contacts.upsert
+	results.push({
+		event: 'contacts.upsert',
+		data: [
+			{
+				id,
+				name: action.fullName || undefined,
+				lid: lidJid || undefined,
+				phoneNumber
+			}
+		]
+	})
+
+	// Emit lid-mapping.update if we have valid LID-PN pair
+	if (lidJid && isLidUser(lidJid) && idIsPn) {
+		results.push({
+			event: 'lid-mapping.update',
+			data: { lid: lidJid, pn: id }
+		})
+	}
+
+	return results
+}
+
+export const emitSyncActionResults = (ev: BaileysEventEmitter, results: SyncActionResult[]): void => {
+	for (const result of results) {
+		if (result.event === 'contacts.upsert') {
+			ev.emit('contacts.upsert', result.data)
+		} else {
+			ev.emit('lid-mapping.update', result.data)
+		}
+	}
+}