From c534bd6cffa7848eab2bc737391d2d355b72096c Mon Sep 17 00:00:00 2001
From: Nicholas Molnar <nicholas@xmtp.com>
Date: Mon, 16 May 2022 10:57:50 -0700
Subject: [PATCH] Add more comments

---
 src/lib/waku_filter/filter_rpc.ts | 12 ++++++++++++
 src/lib/waku_filter/index.ts      | 29 ++++++++++++++++++++++++++---
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/src/lib/waku_filter/filter_rpc.ts b/src/lib/waku_filter/filter_rpc.ts
index 38624bef82..6ce3b7bc23 100644
--- a/src/lib/waku_filter/filter_rpc.ts
+++ b/src/lib/waku_filter/filter_rpc.ts
@@ -7,6 +7,9 @@ export type ContentFilter = {
   contentTopic: string;
 };
 
+/**
+ * FilterRPC represents a message conforming to the Waku Filter protocol
+ */
 export class FilterRPC {
   public constructor(public proto: proto.FilterRPC) {}
 
@@ -27,11 +30,20 @@ export class FilterRPC {
     });
   }
 
+  /**
+   *
+   * @param bytes Uint8Array of bytes from a FilterRPC message
+   * @returns FilterRPC
+   */
   static decode(bytes: Uint8Array): FilterRPC {
     const res = proto.FilterRPC.decode(Reader.create(bytes));
     return new FilterRPC(res);
   }
 
+  /**
+   * Encode the current FilterRPC request to bytes
+   * @returns Uint8Array
+   */
   encode(): Uint8Array {
     return proto.FilterRPC.encode(this.proto).finish();
   }
diff --git a/src/lib/waku_filter/index.ts b/src/lib/waku_filter/index.ts
index 562a19efd8..ee71fb8f07 100644
--- a/src/lib/waku_filter/index.ts
+++ b/src/lib/waku_filter/index.ts
@@ -17,8 +17,17 @@ export const FilterCodec = "/vac/waku/filter/2.0.0-beta1";
 const log = debug("waku:filter");
 
 type FilterSubscriptionOpts = {
+  /**
+   * The Pubsub topic for the subscription
+   */
   topic?: string;
+  /**
+   * Optionally specify a PeerId for the subscription. If not included, will use a random peer
+   */
   peerId?: PeerId;
+  /**
+   * Array of ContentTopics to subscribe to. If empty, will subscribe to all messages on the network
+   */
   contentTopics: string[];
 };
 
@@ -26,6 +35,11 @@ type FilterCallback = (msg: WakuMessage) => void | Promise<void>;
 
 type UnsubscribeFunction = () => Promise<void>;
 
+/**
+ * Implements part of the [Waku v2 Filter protocol](https://rfc.vac.dev/spec/12/).
+ *
+ * WakuFilter can be used as a light filter node, but cannot currently be used as a full node that pushes messages to clients
+ */
 export class WakuFilter {
   private subscriptions: {
     [requestId: string]: FilterCallback;
@@ -36,11 +50,17 @@ export class WakuFilter {
   >;
 
   constructor(public libp2p: Libp2p) {
-    this.libp2p.handle(FilterCodec, this.onRequest.bind(this));
     this.subscriptions = {};
     this.decryptionKeys = new Map();
+    this.libp2p.handle(FilterCodec, this.onRequest.bind(this));
   }
 
+  /**
+   *
+   * @param opts The FilterSubscriptionOpts used to narrow which messages are returned, and which peer to connect to
+   * @param callback A function that will be called on each message returned by the filter
+   * @returns Unsubscribe function that can be used to end the subscription
+   */
   async subscribe(
     opts: FilterSubscriptionOpts,
     callback: FilterCallback
@@ -144,6 +164,7 @@ export class WakuFilter {
       requestId,
       false
     );
+
     const stream = await this.newStream(peer);
     try {
       await pipe([unsubscribeRequest.encode()], lp.encode(), stream.sink);
@@ -167,16 +188,18 @@ export class WakuFilter {
     let peer;
     if (peerId) {
       peer = await this.libp2p.peerStore.get(peerId);
-      if (!peer)
+      if (!peer) {
         throw new Error(
           `Failed to retrieve connection details for provided peer in peer store: ${peerId.toB58String()}`
         );
+      }
     } else {
       peer = await this.randomPeer;
-      if (!peer)
+      if (!peer) {
         throw new Error(
           "Failed to find known peer that registers waku filter protocol"
         );
+      }
     }
     return peer;
   }