fix: stop leaking a native pattern composer on every parse

iOS/Pulsar/Sources/Pulsar/Composers/PatternComposer.swift

@@ -32,14 +32,14 @@ public class PatternComposer: NSObject {
 
   /// `fromMs` starts the pattern that far into its own timeline.
   @objc public func parsePattern(hapticsData: PatternData, fromMs: Double = 0) {
-    releaseAudio()
+    releaseCurrentPattern()
     parse(hapticsData: PatternSeek.pattern(hapticsData, from: fromMs), audioEvent: nil)
   }
 
   /// `start`/`duration` are the authored trim window in the file; `fromMs` seeks the whole
   /// preset, moving audio and haptics together.
   @objc public func parsePatternWithSound(hapticsData: PatternData, uri: String, volume: Float = 1, offset: Double = 0, start: Double = 0, duration: Double = 0, fromMs: Double = 0) {
-    releaseAudio()
+    releaseCurrentPattern()
     let window = PatternSeek.soundWindow(offset: offset, start: start, duration: duration, from: fromMs)
     let audioEvent = makeAudioEvent(
       uri: uri,
@@ -162,7 +162,14 @@ public class PatternComposer: NSObject {
     }
   }
 
-  private func releaseAudio() {
+  private func releaseCurrentPattern() {
+    if let id = continuousPlayerId { engine.removePlayer(id: id) }
+    if let id = discretePlayerId { engine.removePlayer(id: id) }
+    continuousPlayerId = nil
+    discretePlayerId = nil
+    continuousPattern = nil
+    discretePattern = nil
+
     if let id = audioResourceID {
       engine.unregisterAudioResource(id)
       audioResourceID = nil
@@ -202,14 +209,8 @@ public class PatternComposer: NSObject {
 
   @objc public func dispose() {
     stop()
-    if let id = continuousPlayerId { engine.removePlayer(id: id) }
-    if let id = discretePlayerId { engine.removePlayer(id: id) }
-    continuousPlayerId = nil
-    discretePlayerId = nil
-    continuousPattern = nil
-    discretePattern = nil
+    releaseCurrentPattern()
     audioBuffer = nil
     hasSound = false
-    releaseAudio()
   }
 }

iOS/Pulsar/Tests/PulsarTests/CoreHapticsMockTests.swift

@@ -113,6 +113,24 @@ struct CoreHapticsMockTests {
         #expect(last?.sharpness == 0.0)   // clamped low-bound
     }
 
+    @Test func reparsingAPatternComposerReleasesItsPreviousPlayers() {
+        CoreHapticsMock.install()
+        defer { CoreHapticsMock.uninstall() }
+
+        let engine = activeEngine()
+        let composer = PatternComposer(engine: engine, audioSimulator: AudioSimulator())
+        let data = PatternData(line: [[[0, 1.0], [100, 0.0]], [[0, 0.5]]], bar: [[0, 1.0, 0.3]])
+
+        composer.parsePattern(hapticsData: data)
+        let perParse = HapticMockRecorder.shared.playersCreated
+        #expect(perParse >= 1)
+
+        composer.parsePattern(hapticsData: data)
+
+        #expect(HapticMockRecorder.shared.playersCreated == perParse * 2)
+        #expect(HapticMockRecorder.shared.playerStops >= perParse)
+    }
+
     @Test func stopDeactivatesTheRealtimeComposer() {
         CoreHapticsMock.install()
         defer { CoreHapticsMock.uninstall() }

react-native/react-native-pulsar/src/__tests__/usePatternComposer.test.tsx

@@ -0,0 +1,101 @@
+import usePatternComposer from '../usePatternComposer';
+import Pulsar from '../NativeRNPulsar';
+
+jest.mock('react', () => {
+  const actual = jest.requireActual('react');
+  return {
+    ...actual,
+    useCallback: (fn: unknown) => fn,
+    useEffect: (fn: () => void) => {
+      fn();
+    },
+  };
+});
+
+jest.mock('../useSharableState', () => ({
+  useSharableState: (initialValue: number) => {
+    let value = initialValue;
+    return {
+      get: () => value,
+      set: (next: number) => {
+        value = next;
+      },
+    };
+  },
+}));
+
+jest.mock('../NativeRNPulsar', () => ({
+  __esModule: true,
+  default: {
+    PatternComposer_parsePattern: jest.fn(),
+    PatternComposer_parsePatternWithSound: jest.fn(),
+    PatternComposer_play: jest.fn(),
+    PatternComposer_stop: jest.fn(),
+    PatternComposer_release: jest.fn(),
+  },
+}));
+
+const native = Pulsar as jest.Mocked<typeof Pulsar>;
+
+const pattern = (amplitude: number) => ({
+  continuousPattern: {
+    amplitude: [{ time: 0, value: amplitude }],
+    frequency: [{ time: 0, value: 0.5 }],
+  },
+  discretePattern: [{ time: 0, amplitude, frequency: 0.5 }],
+});
+
+const withSound = (amplitude: number) => ({
+  ...pattern(amplitude),
+  sound: { uri: 'file:///clip.wav' },
+});
+
+beforeEach(() => {
+  jest.clearAllMocks();
+  let nextId = 100;
+  native.PatternComposer_parsePattern.mockImplementation(() => nextId++);
+  native.PatternComposer_parsePatternWithSound.mockImplementation(
+    () => nextId++
+  );
+});
+
+it('releases the previous native composer when it parses again', () => {
+  const composer = usePatternComposer();
+
+  composer.parse(pattern(0.4));
+  expect(native.PatternComposer_release).not.toHaveBeenCalled();
+
+  composer.parse(pattern(0.8));
+  expect(native.PatternComposer_release).toHaveBeenCalledWith(100);
+
+  composer.parse(pattern(0.2));
+  expect(native.PatternComposer_release).toHaveBeenCalledWith(101);
+  expect(native.PatternComposer_release).toHaveBeenCalledTimes(2);
+});
+
+it('releases the previous composer before registering the next audio resource', () => {
+  const calls: string[] = [];
+  native.PatternComposer_release.mockImplementation((id) =>
+    calls.push(`release:${id}`)
+  );
+  native.PatternComposer_parsePatternWithSound.mockImplementation(() => {
+    calls.push('parseWithSound');
+    return 200;
+  });
+
+  const composer = usePatternComposer();
+  composer.parse(withSound(0.4));
+  composer.parse(withSound(0.8));
+
+  expect(calls).toEqual(['parseWithSound', 'release:200', 'parseWithSound']);
+});
+
+it('plays the composer it parsed last', () => {
+  const composer = usePatternComposer();
+
+  composer.parse(pattern(0.4));
+  composer.parse(pattern(0.8));
+  composer.play();
+
+  expect(native.PatternComposer_play).toHaveBeenCalledWith(101);
+});

react-native/react-native-pulsar/src/usePatternComposer.ts

@@ -33,7 +33,15 @@ export default function usePatternComposer(pattern?: Pattern): PatternComposer {
     }
   }, []);
 
+  const release = useCallback(() => {
+    const id = patternId.get();
+    if (id === -1) return;
+    Pulsar.PatternComposer_release(id);
+    patternId.set(-1);
+  }, []);
+
   const parse = useCallback((pattern: Pattern) => {
+    release();
     const resolvedUri = pattern.sound ? resolveSoundUri(pattern.sound.uri) : undefined;
     let newPatternId: number;
     if (pattern.sound && resolvedUri) {
@@ -54,12 +62,7 @@ export default function usePatternComposer(pattern?: Pattern): PatternComposer {
       parse(pattern);
     }
 
-    return () => {
-      const id = patternId.get();
-      if (id !== -1) {
-        Pulsar.PatternComposer_release(id);
-      }
-    };
+    return release;
   }, [pattern]);
 
   return { play, stop, parse, isParsed };