Rename everything to welshman

packages/net/Socket.ts

@@ -0,0 +1,116 @@
+import WebSocket from "isomorphic-ws"
+import {Deferred, defer} from '@welshman/lib'
+import type {Message} from '@welshman/util'
+
+export type PlexMessage = [{relays: string[]}, Message]
+
+export type SocketMessage = Message | PlexMessage
+
+export const isMessage = (m: SocketMessage): boolean => typeof m[0] === 'string'
+
+export const asMessage = (m: SocketMessage): Message => isMessage(m) ? m : m[1]
+
+export type SocketOpts = {
+  onOpen: () => void
+  onClose: () => void
+  onError: () => void
+  onMessage: (message: SocketMessage) => void
+}
+
+export class Socket {
+  url: string
+  ws?: WebSocket
+  ready: Deferred<boolean>
+  failedToConnect = false
+
+  constructor(url: string, readonly opts: SocketOpts) {
+    this.url = url
+    this.ready = defer()
+  }
+
+  isPending() {
+    return !this.ws && !this.failedToConnect
+  }
+
+  isConnecting() {
+    return this.ws?.readyState === WebSocket.CONNECTING
+  }
+
+  isReady() {
+    return this.ws?.readyState === WebSocket.OPEN
+  }
+
+  isClosing() {
+    return this.ws?.readyState === WebSocket.CLOSING
+  }
+
+  isClosed() {
+    return this.ws?.readyState === WebSocket.CLOSED
+  }
+
+  isHealthy() {
+    return this.isPending() || this.isConnecting() || this.isReady()
+  }
+
+  onOpen = () => {
+    this.ready.resolve(true)
+    this.opts.onOpen()
+  }
+
+  onError = () => {
+    this.opts.onError()
+    this.disconnect()
+  }
+
+  onMessage = (event: {data: string}) => {
+    try {
+      const message = JSON.parse(event.data as string)
+
+      if (Array.isArray(message)) {
+        this.opts.onMessage(message as Message)
+      } else {
+        console.warn("Invalid messages received:", message)
+      }
+    } catch (e) {
+      // pass
+    }
+  }
+
+  send = (message: any) => {
+    if (!this.ws) {
+      throw new Error('Send attempted before socket was opened')
+    }
+
+    this.ws.send(JSON.stringify(message))
+  }
+
+  connect = () => {
+    if (this.ws) {
+      throw new Error(`Already attempted connection for ${this.url}`)
+    }
+
+    try {
+      this.ws = new WebSocket(this.url)
+      this.ws.onopen = this.onOpen
+      this.ws.onerror = this.onError
+      this.ws.onmessage = this.onMessage
+      this.ws.onclose = this.disconnect
+    } catch (e) {
+      this.failedToConnect = true
+    }
+  }
+
+  disconnect = () => {
+    if (this.ws) {
+      const currentWs = this.ws
+
+      this.ready.then(() => currentWs.close())
+      this.ready = defer()
+      this.opts.onClose()
+      this.ws = undefined
+
+      // Resolve a different instance of the promise
+      this.ready.resolve(false)
+    }
+  }
+}