fix(playback): track mpv recording auto-stop replies

Entire-Checkpoint: f957cd9849e0

apps/electron-backend/native/src/embedded_mpv.mm

@@ -1731,14 +1731,32 @@ Napi::Value LoadPlayback(const Napi::CallbackInfo& info)
     }
     if (recordingActive) {
         const char* disabledValue = "";
+        const uint64_t stopRecordingRequestId = nextAsyncRequestId();
+        {
+            std::lock_guard<std::mutex> lock(session->mutex);
+            session->pendingRecordingStopRequestId = stopRecordingRequestId;
+            session->pendingRecordingStopStartedAt =
+                session->snapshot.recordingStartedAt;
+        }
+
         const int stopResult = mpv_set_property_async(
             session->handle,
-            nextAsyncRequestId(),
+            stopRecordingRequestId,
             "stream-record",
             MPV_FORMAT_STRING,
             const_cast<char**>(&disabledValue)
         );
         if (stopResult < 0) {
+            {
+                std::lock_guard<std::mutex> lock(session->mutex);
+                if (
+                    session->pendingRecordingStopRequestId ==
+                    stopRecordingRequestId
+                ) {
+                    session->pendingRecordingStopRequestId = 0;
+                    session->pendingRecordingStopStartedAt.clear();
+                }
+            }
             updateSessionError(session, mpv_error_string(stopResult));
             throw Napi::Error::New(
                 env,

apps/electron-backend/src/app/services/embedded-mpv-native-source.spec.ts

@@ -0,0 +1,48 @@
+import { readFileSync } from 'fs';
+import path from 'path';
+
+describe('Embedded MPV native source recording invariants', () => {
+    const nativeSource = readFileSync(
+        path.resolve(__dirname, '../../../native/src/embedded_mpv.mm'),
+        'utf8'
+    );
+
+    function functionBody(name: string): string {
+        const start = nativeSource.indexOf(`Napi::Value ${name}(`);
+        expect(start).toBeGreaterThanOrEqual(0);
+
+        const bodyStart = nativeSource.indexOf('{', start);
+        expect(bodyStart).toBeGreaterThanOrEqual(0);
+
+        let depth = 0;
+        for (let index = bodyStart; index < nativeSource.length; index += 1) {
+            if (nativeSource[index] === '{') {
+                depth += 1;
+            }
+            if (nativeSource[index] === '}') {
+                depth -= 1;
+            }
+            if (depth === 0) {
+                return nativeSource.slice(bodyStart, index + 1);
+            }
+        }
+
+        throw new Error(`Unable to read ${name} body.`);
+    }
+
+    it('tracks LoadPlayback recording auto-stop replies through the reconciler', () => {
+        const body = functionBody('LoadPlayback');
+
+        expect(body).toContain(
+            'const uint64_t stopRecordingRequestId = nextAsyncRequestId();'
+        );
+        expect(body).toContain(
+            'session->pendingRecordingStopRequestId = stopRecordingRequestId;'
+        );
+        expect(body).toContain(
+            'session->pendingRecordingStopStartedAt =\n' +
+                '                session->snapshot.recordingStartedAt;'
+        );
+        expect(body).toContain('stopRecordingRequestId,');
+    });
+});