narrow Message some

src/js/game.ts

@@ -1,4 +1,4 @@
-import type { Message } from "../shared/types"
+import type { GameStartMessage } from "../shared/types"
 import { GameContext, type InputState } from "../shared/game"
 import { focusInput } from "./focus"
 import { $$ } from "./dom"
@@ -29,7 +29,7 @@ let pressed: InputState = {
   justReleased: new Set(),
 }
 
-export async function handleGameStart(msg: Message) {
+export async function handleGameStart(msg: GameStartMessage) {
   const msgId = msg.id as string
   const name = msg.data as string
 

src/shared/types.ts

@@ -8,6 +8,7 @@ export type Message = {
     | SaveFileMessage
     | SessionStartMessage
     | SessionUpdateMessage
+    | GameStartMessage
 
 export type MessageType = "error" | "input" | "output" | "commands" | "save-file"
     | "game:start"
@@ -53,3 +54,8 @@ export type SessionUpdateMessage = {
     type: "session:update"
     data: Record<string, string>
 }
+
+export type GameStartMessage = {
+    id: string
+    data: string
+}