Refactor media devices to live outside React as Observables

This moves the media devices state out of React to further our transition to a MVVM architecture in which we can more easily model and store complex application state. I have created an AppViewModel to act as the overarching state holder for any future non-React state we end up creating, and the MediaDevices reside within this. We should move more application logic (including the CallViewModel itself) there in the future.

src/useAudioContext.test.tsx

@@ -10,10 +10,12 @@ import { type FC } from "react";
 import { render } from "@testing-library/react";
 import userEvent, { type UserEvent } from "@testing-library/user-event";
 import { BrowserRouter } from "react-router-dom";
+import { of } from "rxjs";
 
-import { deviceStub, MediaDevicesContext } from "./livekit/MediaDevicesContext";
+import { MediaDevicesContext } from "./MediaDevicesContext";
 import { useAudioContext } from "./useAudioContext";
 import { soundEffectVolume as soundEffectVolumeSetting } from "./settings/settings";
+import { mockMediaDevices } from "./utils/test";
 
 const staticSounds = Promise.resolve({
   aSound: new ArrayBuffer(0),
@@ -102,13 +104,21 @@ afterEach(() => {
 });
 
 test("can play a single sound", async () => {
-  const { findByText } = render(<TestComponentWrapper />);
+  const { findByText } = render(
+    <MediaDevicesContext.Provider value={mockMediaDevices({})}>
+      <TestComponentWrapper />
+    </MediaDevicesContext.Provider>,
+  );
   await user.click(await findByText("Valid sound"));
   expect(testAudioContext.createBufferSource).toHaveBeenCalledOnce();
 });
 
 test("will ignore sounds that are not registered", async () => {
-  const { findByText } = render(<TestComponentWrapper />);
+  const { findByText } = render(
+    <MediaDevicesContext.Provider value={mockMediaDevices({})}>
+      <TestComponentWrapper />
+    </MediaDevicesContext.Provider>,
+  );
   await user.click(await findByText("Invalid sound"));
   expect(testAudioContext.createBufferSource).not.toHaveBeenCalled();
 });
@@ -116,19 +126,13 @@ test("will ignore sounds that are not registered", async () => {
 test("will use the correct device", () => {
   render(
     <MediaDevicesContext.Provider
-      value={{
-        audioInput: deviceStub,
+      value={mockMediaDevices({
         audioOutput: {
-          selectedId: "chosen-device",
-          selectedGroupId: "",
-          available: new Map(),
+          available$: of(new Map<never, never>()),
+          selected$: of({ id: "chosen-device", virtualEarpiece: false }),
           select: () => {},
-          useAsEarpiece: false,
         },
-        videoInput: deviceStub,
-        startUsingDeviceNames: () => {},
-        stopUsingDeviceNames: () => {},
-      }}
+      })}
     >
       <TestComponentWrapper />
     </MediaDevicesContext.Provider>,
@@ -139,7 +143,11 @@ test("will use the correct device", () => {
 
 test("will use the correct volume level", async () => {
   soundEffectVolumeSetting.setValue(0.33);
-  const { findByText } = render(<TestComponentWrapper />);
+  const { findByText } = render(
+    <MediaDevicesContext.Provider value={mockMediaDevices({})}>
+      <TestComponentWrapper />
+    </MediaDevicesContext.Provider>,
+  );
   await user.click(await findByText("Valid sound"));
   expect(testAudioContext.gain.gain.setValueAtTime).toHaveBeenCalledWith(
     0.33,
@@ -151,19 +159,13 @@ test("will use the correct volume level", async () => {
 test("will use the pan if earpiece is selected", async () => {
   const { findByText } = render(
     <MediaDevicesContext.Provider
-      value={{
-        audioInput: deviceStub,
+      value={mockMediaDevices({
         audioOutput: {
-          selectedId: "chosen-device",
-          selectedGroupId: "",
-          available: new Map(),
+          available$: of(new Map<never, never>()),
+          selected$: of({ id: "chosen-device", virtualEarpiece: true }),
           select: () => {},
-          useAsEarpiece: true,
         },
-        videoInput: deviceStub,
-        startUsingDeviceNames: () => {},
-        stopUsingDeviceNames: () => {},
-      }}
+      })}
     >
       <TestComponentWrapper />
     </MediaDevicesContext.Provider>,