feat: initial scaffolding, client can connect with a user name

shared.ts

@@ -0,0 +1,108 @@
+// includes types that are shared between the client and server
+// e.g. the websocket message protocol
+
+export interface User {
+  name: string;
+  uid: string;
+}
+
+export interface ClientJoinMessage {
+  type: "JOIN";
+  payload: {
+    username: string;
+  };
+}
+
+export interface ClientLeaveMessage {
+  type: "LEAVE";
+  payload: {
+    username: string;
+  };
+}
+
+export interface ClientChatMessage {
+  type: "CHAT_MESSAGE";
+  payload: {
+    content: string;
+  };
+}
+
+export interface ClientDeleteMessage {
+  type: "DELETE_MESSAGE";
+  payload: {
+    messageId: string;
+  };
+}
+
+export interface ClientEditMessage {
+  type: "EDIT_MESSAGE";
+  payload: {
+    messageId: string;
+    content: string;
+  };
+}
+
+export type ClientMessage =
+  | ClientJoinMessage
+  | ClientLeaveMessage
+  | ClientChatMessage
+  | ClientDeleteMessage
+  | ClientEditMessage;
+
+// Server messages
+
+interface ChatMessage {
+  id: string;
+  content: string;
+  timestamp: number;
+  author: User;
+}
+
+interface ServerUserJoinedMessage {
+  type: "USER_JOINED";
+  payload: {
+    user: User;
+  };
+}
+
+interface ServerUserLeftMessage {
+  type: "USER_LEFT";
+  payload: {
+    user: User;
+  };
+}
+
+interface ServerChatMessage {
+  type: "CHAT_MESSAGE";
+  payload: ChatMessage;
+}
+
+interface ServerMessageDeletedMessage {
+  type: "MESSAGE_DELETED";
+  payload: {
+    messageId: string;
+  };
+}
+
+interface ServerMessageEditedMessage {
+  type: "MESSAGE_EDITED";
+  payload: {
+    messageId: string;
+    content: string;
+  };
+}
+
+interface ServerUserListMessage {
+  type: "USER_LIST";
+  payload: {
+    users: User[];
+  };
+}
+
+export type ServerMessage =
+  | ServerUserJoinedMessage
+  | ServerUserLeftMessage
+  | ServerChatMessage
+  | ServerMessageDeletedMessage
+  | ServerMessageEditedMessage
+  | ServerUserListMessage;