feat: explicit type the message events

.vscode/settings.json

@@ -7,4 +7,4 @@
   "[json]": {
     "editor.defaultFormatter": "denoland.vscode-deno"
   }
-}
+}

examples/abort-controller.ts

@@ -12,6 +12,7 @@ const receiver = new LogReceiver({
 console.log("Log receiver running.. ");
 
 receiver.on("event", (message) => console.log(message));
-receiver.on("close", () => console.log("Closed the socket"));
 
 controller.abort();
+
+console.log("Closed the socket")

src/logReceiver.ts

@@ -2,7 +2,7 @@
 import { EventEmitter } from "node:events";
 import { createSocket, type RemoteInfo, type Socket } from "node:dgram";
 import { parsePacket } from "./parser.ts";
-import type { EventData } from "./types.ts";
+import type { EventData, TypedEventEmitter } from "./types.ts";
 
 /**
  * The socket options for the UDP socket
@@ -30,6 +30,11 @@ export interface LogReceiverOptions {
   signal?: AbortSignal;
 }
 
+type MessageEvents = {
+  error: (error: Error) => void;
+  event: (message: EventData) => void;
+};
+
 /**
  * An event emitter that will emit a message event when a valid UDP log is created on the server
  *
@@ -94,7 +99,7 @@ export interface LogReceiverOptions {
  *
  * For security reasons, you should always use a log secret to prevent evaluation of potentially malicious messages. Do this by looking at the password field. In order to set up the log secret, you can use the `sv_logsecret` command
  */
-export class LogReceiver extends EventEmitter implements Disposable {
+export class LogReceiver extends (EventEmitter as new () => TypedEventEmitter<MessageEvents>) implements Disposable {
   #socket: Socket;
 
   /**
@@ -118,10 +123,7 @@ export class LogReceiver extends EventEmitter implements Disposable {
 
     this.#socket.bind(port, address);
 
-    this.#socket.on("close", () => this.emit("close"));
-    this.#socket.on("connect", () => this.emit("connect"));
     this.#socket.on("error", (error) => this.emit("error", error));
-    this.#socket.on("listening", () => this.emit("listening"));
     this.#socket.on("message", (buffer, serverInfo) => this.#handleMessage(buffer, serverInfo));
   }
 

src/types.ts

@@ -24,3 +24,47 @@ export interface EventData extends ParsedLogMessage {
    */
   socket: RemoteInfo;
 }
+
+type EventMap = {
+  // deno-lint-ignore no-explicit-any
+  [key: string]: (...args: any[]) => void;
+};
+
+/**
+ * Copied from https://github.com/andywer/typed-emitter/blob/master/index.d.ts
+ * Type-safe event emitter
+ *
+ * Use it like this:
+ *
+ * ```ts
+ * type MyEvents = {
+ *   error: (error: Error) => void;
+ *   message: (from: string, content: string) => void;
+ * }
+ *
+ * const myEmitter = new EventEmitter() as TypedEmitter<MyEvents>;
+ *
+ * myEmitter.emit("error", "x")  // <- Will catch this type error;
+ * ```
+ */
+export interface TypedEventEmitter<Events extends EventMap> {
+  addListener<E extends keyof Events>(event: E, listener: Events[E]): this;
+  on<E extends keyof Events>(event: E, listener: Events[E]): this;
+  once<E extends keyof Events>(event: E, listener: Events[E]): this;
+  prependListener<E extends keyof Events>(event: E, listener: Events[E]): this;
+  prependOnceListener<E extends keyof Events>(event: E, listener: Events[E]): this;
+
+  off<E extends keyof Events>(event: E, listener: Events[E]): this;
+  removeAllListeners<E extends keyof Events>(event?: E): this;
+  removeListener<E extends keyof Events>(event: E, listener: Events[E]): this;
+
+  emit<E extends keyof Events>(event: E, ...args: Parameters<Events[E]>): boolean;
+  // The sloppy `eventNames()` return type is to mitigate type incompatibilities - see #5
+  eventNames(): (keyof Events | string | symbol)[];
+  rawListeners<E extends keyof Events>(event: E): Events[E][];
+  listeners<E extends keyof Events>(event: E): Events[E][];
+  listenerCount<E extends keyof Events>(event: E): number;
+
+  getMaxListeners(): number;
+  setMaxListeners(maxListeners: number): this;
+}

tests/parser.bench.ts

@@ -22,4 +22,4 @@ Deno.bench("Can parse a password", { baseline: true, group: "password" }, () =>
 
   assertEquals(result?.message, body.substring(2));
   assertEquals(result?.password, password);
-});
+});

tests/parser.test.ts

@@ -57,4 +57,4 @@ Deno.test("Can parse a password", () => {
 
   assertEquals(result?.message, body.substring(2));
   assertEquals(result?.password, password);
-});
+});