Fix PR feedback

- Fix missing typescript types
- Use Safari 13 compatible OfflineAudioContext constructor - this may
  prove pointless due to lack of < 44100 sample rate support, but is an
  easier starting point to try things out.

package.json

@@ -24,6 +24,7 @@
   },
   "homepage": "https://github.com/microbit-foundation/micropython-microbit-v2-simulator#readme",
   "devDependencies": {
+    "@types/emscripten": "^1.39.10",
     "esbuild": "^0.14.49",
     "prettier": "2.6.0",
     "vitest": "^0.22.1"

src/board/audio/index.ts

@@ -201,11 +201,11 @@ export class BoardAudio {
     const recorder = this.context!.createScriptProcessor(2048, 1, 1);
     recorder.onaudioprocess = (e) => {
       const offlineContext = new (window.OfflineAudioContext ||
-        window.webkitOfflineAudioContext)({
-        sampleRate,
-        length: sampleRate * (e.inputBuffer.length / e.inputBuffer.sampleRate),
-        numberOfChannels: 1,
-      });
+        window.webkitOfflineAudioContext)(
+        1,
+        sampleRate * (e.inputBuffer.length / e.inputBuffer.sampleRate),
+        sampleRate
+      );
       const source = offlineContext.createBufferSource();
       source.buffer = e.inputBuffer;
       source.connect(offlineContext.destination);

src/board/wasm.ts

@@ -2,7 +2,7 @@ import { Board } from ".";
 import * as conversions from "./conversions";
 import { FileSystem } from "./fs";
 
-export interface EmscriptenModule {
+export interface SimulatorEmscriptenModule extends EmscriptenModule {
   cwrap: any;
   ExitStatus: Error;
 
@@ -15,9 +15,6 @@ export interface EmscriptenModule {
   _microbit_hal_level_detector_callback(level: number): void;
   _microbit_radio_rx_buffer(): number;
 
-  HEAPU8: Uint8Array;
-  HEAPU32: Uint32Array;
-
   // Added by us at module creation time for jshal to access.
   board: Board;
   fs: FileSystem;
@@ -27,7 +24,7 @@ export interface EmscriptenModule {
 export class ModuleWrapper {
   private main: () => Promise<void>;
 
-  constructor(private module: EmscriptenModule) {
+  constructor(private module: SimulatorEmscriptenModule) {
     const main = module.cwrap("mp_js_main", "null", ["number"], {
       async: true,
     });

src/jshal.d.ts

@@ -1,15 +1,10 @@
-import { EmscriptenModule } from "./board/wasm";
+import { SimulatorEmscriptenModule } from "./board/wasm";
 
 global {
   // In reality this is a local variable as jshal.js is splatted into the generated code.
-  declare const Module: EmscriptenModule;
+  declare const Module: SimulatorEmscriptenModule;
   declare const LibraryManager: {
     library: any;
   };
-
-  // Just what we need. There are lots more Emscripten helpers available.
-  declare function UTF8ToString(ptr: number, len?: number);
-  declare function stringToUTF8(s: string, buf: number, len: number);
-  declare function lengthBytesUTF8(s: string);
   declare function mergeInto(library: any, functions: Record<string, function>);
 }

src/simulator.ts

@@ -1,6 +1,6 @@
 import * as conversions from "./board/conversions";
 import { FileSystem } from "./board/fs";
-import { EmscriptenModule } from "./board/wasm";
+import { SimulatorEmscriptenModule } from "./board/wasm";
 import {
   Board,
   createBoard,
@@ -11,7 +11,7 @@ import {
 declare global {
   interface Window {
     // Provided by firmware.js
-    createModule: (args: object) => Promise<EmscriptenModule>;
+    createModule: (args: object) => Promise<SimulatorEmscriptenModule>;
   }
 }