feat: reach a mouse through OpenMouse Bridge where WebHID is missing

src/bridge-hid.test.ts

@@ -0,0 +1,128 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+
+import { bridgeHid, type BridgeTransport } from "./bridge-hid.ts";
+
+interface Fake {
+  transport: BridgeTransport;
+  sent: Record<string, unknown>[];
+  reply: (frame: Record<string, unknown>) => void;
+}
+
+function fakeTransport(): Fake {
+  const sent: Record<string, unknown>[] = [];
+  const transport: BridgeTransport = {
+    send: (frame) => void sent.push(JSON.parse(frame) as Record<string, unknown>),
+    close: () => undefined,
+    onMessage: null,
+    onClose: null,
+  };
+  return {
+    transport,
+    sent,
+    reply: (frame) => transport.onMessage?.(JSON.stringify(frame)),
+  };
+}
+
+const MOUSE = {
+  key: "3554:f58c:1",
+  vendorId: 0x3554,
+  productId: 0xf58c,
+  productName: "Pulsar X2",
+  collections: [{ usagePage: 0xff00, usage: 1, inputReports: [{ reportId: 8, items: [] }], outputReports: [], featureReports: [], children: [] }],
+};
+
+test("drives a device end to end over the socket", async () => {
+  const fake = fakeTransport();
+  const hid = bridgeHid(fake.transport);
+
+  const listing = hid.getDevices();
+  assert.equal(fake.sent[0].type, "list");
+  assert.ok(Array.isArray(fake.sent[0].vendorIds) && (fake.sent[0].vendorIds as number[]).length > 0);
+  fake.reply({ id: fake.sent[0].id, ok: true, devices: [MOUSE] });
+
+  const [device] = await listing;
+  assert.equal(device.productName, "Pulsar X2");
+  assert.equal(device.collections[0].inputReports[0].reportId, 8);
+  assert.equal(device.opened, false);
+
+  const opening = device.open();
+  assert.deepEqual({ ...fake.sent[1] }, { id: fake.sent[1].id, type: "open", device: MOUSE.key });
+  fake.reply({ id: fake.sent[1].id, ok: true });
+  await opening;
+  assert.equal(device.opened, true);
+
+  const sending = device.sendReport(8, new Uint8Array([1, 2, 3]));
+  assert.equal(fake.sent[2].type, "sendReport");
+  assert.equal(fake.sent[2].reportId, 8);
+  assert.deepEqual(fake.sent[2].data, [1, 2, 3]);
+  fake.reply({ id: fake.sent[2].id, ok: true });
+  await sending;
+
+  const reports: number[][] = [];
+  device.addEventListener("inputreport", (event) => {
+    reports.push([event.reportId, event.data.byteLength, event.data.getUint8(0)]);
+  });
+  fake.reply({ type: "inputreport", device: MOUSE.key, reportId: 8, data: [42, 7] });
+  assert.deepEqual(reports, [[8, 2, 42]]);
+
+  const feature = device.receiveFeatureReport(5);
+  fake.reply({ id: fake.sent[3].id, ok: true, data: [9, 9] });
+  assert.equal((await feature).getUint8(1), 9);
+
+  // Stops the enumeration poll, which would otherwise hold the test open.
+  fake.transport.onClose?.();
+});
+
+test("a rejected request surfaces the reason Bridge gave", async () => {
+  const fake = fakeTransport();
+  const hid = bridgeHid(fake.transport);
+
+  const listing = hid.getDevices();
+  fake.reply({ id: fake.sent[0].id, ok: false, error: "no interface answered" });
+
+  await assert.rejects(listing, /no interface answered/);
+  fake.transport.onClose?.();
+});
+
+test("re-enumeration keeps device identity and reports hot-plug both ways", async () => {
+  const fake = fakeTransport();
+  const hid = bridgeHid(fake.transport);
+  const events: string[] = [];
+  hid.addEventListener("connect", (event) => void events.push(`connect:${event.device.productName}`));
+  hid.addEventListener("disconnect", (event) => void events.push(`disconnect:${event.device.productName}`));
+
+  const first = hid.getDevices();
+  fake.reply({ id: fake.sent[0].id, ok: true, devices: [MOUSE] });
+  const [device] = await first;
+
+  const second = hid.getDevices();
+  fake.reply({ id: fake.sent[1].id, ok: true, devices: [MOUSE] });
+  const [again] = await second;
+  assert.equal(again, device, "the same physical device must stay the same object");
+
+  const third = hid.getDevices();
+  fake.reply({ id: fake.sent[2].id, ok: true, devices: [] });
+  assert.deepEqual(await third, []);
+
+  assert.deepEqual(events, ["connect:Pulsar X2", "disconnect:Pulsar X2"]);
+  fake.transport.onClose?.();
+});
+
+test("a dropped socket closes every device and rejects what was in flight", async () => {
+  const fake = fakeTransport();
+  const hid = bridgeHid(fake.transport);
+
+  const listing = hid.getDevices();
+  fake.reply({ id: fake.sent[0].id, ok: true, devices: [MOUSE] });
+  const [device] = await listing;
+  const opening = device.open();
+  fake.reply({ id: fake.sent[1].id, ok: true });
+  await opening;
+
+  const pending = device.receiveFeatureReport(5);
+  fake.transport.onClose?.();
+
+  await assert.rejects(pending, /disconnected/);
+  assert.equal(device.opened, false);
+});