feat(casting): add Chromecast capability detection

utils/casting/capabilities.test.ts

@@ -0,0 +1,69 @@
+import { describe, expect, test } from "bun:test";
+import { CONSERVATIVE_CAPABILITIES, detectCapabilities } from "./capabilities";
+
+describe("detectCapabilities", () => {
+  test("unknown device falls back to the conservative baseline", () => {
+    const caps = detectCapabilities(
+      { modelName: "Some Unknown TV" },
+      { profileMode: "auto" },
+    );
+    expect(caps).toEqual(CONSERVATIVE_CAPABILITIES);
+  });
+
+  test("null device falls back to the conservative baseline", () => {
+    const caps = detectCapabilities(null, { profileMode: "auto" });
+    expect(caps).toEqual(CONSERVATIVE_CAPABILITIES);
+  });
+
+  test('plain "Chromecast" (gen 1/2/3) gets the conservative baseline', () => {
+    const caps = detectCapabilities(
+      { modelName: "Chromecast" },
+      { profileMode: "auto" },
+    );
+    expect(caps.hevc).toBe(false);
+    expect(caps.maxResolution).toBe(1080);
+    expect(caps.maxAudioChannels).toBe(2);
+  });
+
+  test("Chromecast Ultra is recognised with HEVC + 4K", () => {
+    const caps = detectCapabilities(
+      { modelName: "Chromecast Ultra" },
+      { profileMode: "auto" },
+    );
+    expect(caps.hevc).toBe(true);
+    expect(caps.maxResolution).toBe(2160);
+  });
+
+  test('"force-h264" override disables HEVC even on a capable device', () => {
+    const caps = detectCapabilities(
+      { modelName: "Chromecast Ultra" },
+      { profileMode: "force-h264" },
+    );
+    expect(caps.hevc).toBe(false);
+    expect(caps.hevc10bit).toBe(false);
+  });
+
+  test('"force-hevc" override enables HEVC on the conservative baseline', () => {
+    const caps = detectCapabilities(
+      { modelName: "Chromecast" },
+      { profileMode: "force-hevc" },
+    );
+    expect(caps.hevc).toBe(true);
+  });
+
+  test("maxBitrate override clamps but never raises the bitrate", () => {
+    const lowered = detectCapabilities(
+      { modelName: "Chromecast" },
+      { profileMode: "auto", maxBitrate: 3_000_000 },
+    );
+    expect(lowered.maxVideoBitrate).toBe(3_000_000);
+
+    const raised = detectCapabilities(
+      { modelName: "Chromecast" },
+      { profileMode: "auto", maxBitrate: 999_000_000 },
+    );
+    expect(raised.maxVideoBitrate).toBe(
+      CONSERVATIVE_CAPABILITIES.maxVideoBitrate,
+    );
+  });
+});