[dev]: Define explicitly types inside game logic

www/src/game-of-life/index.d.ts

@@ -1,3 +1,18 @@
+type BGModule = {}
+type WASMModule = { memory: WebAssembly.Memory }
+
 declare module 'wasm-game-of-life/wasm_game_of_life_bg.wasm' {
-  export default function wasm(importObject: { './wasm_game_of_life_bg.js': any }): Promise<any>
-}
+  export default function wasm(importObject: { './wasm_game_of_life_bg.js': BGModule }): Promise<WASMModule>
+}
+
+declare module 'wasm-game-of-life/wasm_game_of_life_bg.js' {
+  import { Universe, Cell } from "wasm-game-of-life"
+
+  function __wbg_set_wasm(wasm: WASMModule): void
+
+  export {
+    __wbg_set_wasm,
+    Universe,
+    Cell,
+  }
+}

www/src/game-of-life/index.ts

@@ -1,14 +1,15 @@
+/// <reference types="./index.d.ts" />
 import wasm from "wasm-game-of-life/wasm_game_of_life_bg.wasm";
 import * as bg from "wasm-game-of-life/wasm_game_of_life_bg.js"
 
-export default function run(canvas) {
+export default function run(canvas: HTMLCanvasElement): void {
   wasm({'./wasm_game_of_life_bg.js': bg}).then(wasm => {
     bg.__wbg_set_wasm(wasm)
     main(bg.Universe, bg.Cell, wasm.memory, canvas)
   })
 }
 
-function main(Universe, Cell, memory, canvas) {
+function main(Universe: typeof bg.Universe, Cell: typeof bg.Cell, memory: WebAssembly.Memory, canvas: HTMLCanvasElement) {
   const CELL_SIZE = 5; // px
   const GRID_COLOR = "#CCCCCC";
   const DEAD_COLOR = "#FFFFFF";
@@ -25,6 +26,9 @@ function main(Universe, Cell, memory, canvas) {
   canvas.width = (CELL_SIZE + 1) * width + 1;
 
   const ctx = canvas.getContext('2d');
+  if (ctx === null) {
+    throw new Error("canvas 2d context not found")
+  }
 
   const fps = new class {
     fps: HTMLDivElement;