fix: clear lens cache on re-bootstrap (#4)

## Summary

- Fix stale lens references after SDK re-initialization: the lens cache
retained objects from the old `lensRepository`, causing `fetchLens` to
return lenses bound to a destroyed kit instance
- Clear `lensCache` and reset `lenses` state at the start of the
bootstrap effect, before the new kit is created

## Test plan

- [ ] New test: "should clear lens cache on re-bootstrap" — verifies
that after a `stabilityKey` change triggers re-bootstrap, previously
cached lenses are evicted and `fetchLens` calls the new kit's `loadLens`
- [ ] Full test suite passes

Author: msilivonik-sc

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "@snap/react-camera-kit",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "React Camera Kit for web applications",
   "type": "module",
   "main": "./dist/cjs/index.js",

package.json

@@ -382,6 +382,62 @@ describe("CameraKitProvider", () => {
       expect(result.current.lenses).toHaveLength(2);
     });
 
+    it("should clear lens cache on re-bootstrap", async () => {
+      const mockLens = { id: "lens-1", groupId: "group-1" } as Lens;
+      (mockKit.lensRepository.loadLens as any).mockResolvedValue(mockLens);
+
+      const mockKit2 = {
+        destroy: jest.fn().mockResolvedValue(undefined),
+        createSession: jest.fn().mockResolvedValue(mockSession),
+        lensRepository: {
+          loadLens: jest.fn().mockResolvedValue(mockLens),
+          loadLensGroups: jest.fn(),
+        },
+      } as any;
+
+      mockBootstrapCameraKit.mockReset().mockResolvedValueOnce(mockKit).mockResolvedValueOnce(mockKit2);
+
+      let stabilityKey = "key-1";
+      const wrapper = ({ children }: { children: React.ReactNode }) => (
+        <CameraKitProvider apiToken="test-token" stabilityKey={stabilityKey}>
+          {children}
+        </CameraKitProvider>
+      );
+
+      const { result, rerender } = renderHook(() => useCameraKit(), { wrapper });
+
+      await waitFor(() => {
+        expect(result.current.sdkStatus).toBe("ready");
+      });
+
+      // Fetch a lens — populates the cache
+      await act(async () => {
+        await result.current.fetchLens("lens-1", "group-1");
+      });
+
+      expect(mockKit.lensRepository.loadLens).toHaveBeenCalledTimes(1);
+      expect(result.current.lenses).toHaveLength(1);
+
+      // Trigger re-bootstrap by changing stabilityKey
+      stabilityKey = "key-2";
+      rerender();
+
+      await waitFor(() => {
+        expect(result.current.sdkStatus).toBe("ready");
+        expect(mockBootstrapCameraKit).toHaveBeenCalledTimes(2);
+      });
+
+      // Lenses state should have been cleared
+      expect(result.current.lenses).toHaveLength(0);
+
+      // Fetch the same lens again — should NOT hit cache, should call new kit's loadLens
+      await act(async () => {
+        await result.current.fetchLens("lens-1", "group-1");
+      });
+
+      expect(mockKit2.lensRepository.loadLens).toHaveBeenCalledWith("lens-1", "group-1");
+    });
+
     it("should apply lens", async () => {
       const mockLens = { id: "lens-1", groupId: "group-1" } as Lens;
       (mockKit.lensRepository.loadLens as any).mockResolvedValue(mockLens);

src/CameraKitProvider.test.tsx

@@ -352,6 +352,10 @@ export const CameraKitProvider: React.FC<CameraKitProviderProps> = ({
     const abortController = new AbortController();
     const emit = eventFactoryRef.current?.();
 
+    // Clear stale lens cache — the old kit's lensRepository is no longer valid.
+    lensCache.current.clear();
+    setLenses([]);
+
     setCameraKitState({ status: "initializing" });
     emit?.({ kind: "bootstrap-attempt" });
     log.info("bootstrap_attempt");