Add skipDuplicateCheck option

Author: dapplion

src/index.ts

@@ -85,6 +85,10 @@ type ReceivedMessageResult =
   | ({ code: MessageStatus.invalid; msgIdStr?: MsgIdStr } & RejectReasonObj)
   | { code: MessageStatus.valid; messageId: MessageId; msg: Message }
 
+export type PublishOpts = {
+  skipDuplicateCheck: boolean
+}
+
 export const multicodec: string = constants.GossipsubIDv11
 
 export interface GossipsubOpts extends GossipsubOptsSpec, PubSubInit {
@@ -1922,7 +1926,7 @@ export class GossipSub extends EventEmitter<GossipsubEvents> implements Initiali
    *
    * For messages not from us, this class uses `forwardMessage`.
    */
-  async publish(topic: TopicStr, data: Uint8Array): Promise<PublishResult> {
+  async publish(topic: TopicStr, data: Uint8Array, opts?: PublishOpts): Promise<PublishResult> {
     const transformedData = this.dataTransform ? this.dataTransform.outboundTransform(topic, data) : data
 
     if (this.publishConfig == null) {
@@ -1936,7 +1940,7 @@ export class GossipSub extends EventEmitter<GossipsubEvents> implements Initiali
     const msgId = await this.msgIdFn(msg)
     const msgIdStr = this.msgIdToStrFn(msgId)
 
-    if (this.seenCache.has(msgIdStr)) {
+    if (!opts?.skipDuplicateCheck && this.seenCache.has(msgIdStr)) {
       // This message has already been seen. We don't re-publish messages that have already
       // been published on the network.
       throw Error('PublishError.Duplicate')