fix first event tracking property

Author: Emil Hartz

__tests__/useSwipeable.spec.tsx

@@ -181,6 +181,29 @@ describe("useSwipeable", () => {
     );
   });
 
+  it("correctly tracks the first event", () => {
+    const onSwiping = jest.fn();
+    const { getByText } = render(<SwipeableUsingHook onSwiping={onSwiping} />);
+
+    const touchArea = getByText(TESTING_TEXT);
+
+    fireEvent[TS](touchArea, cte({ x: 100, y: 100 }));
+    fireEvent[TM](touchArea, cte({ x: 100, y: 125 }));
+    fireEvent[TM](touchArea, cte({ x: 100, y: 150 }));
+    fireEvent[TM](touchArea, cte({ x: 100, y: 175 }));
+    fireEvent[TE](touchArea, cte({}));
+
+    expect(onSwiping.mock.calls[0][0]).toEqual(
+      expect.objectContaining({ first: true })
+    );
+    expect(onSwiping.mock.calls[1][0]).toEqual(
+      expect.objectContaining({ first: false })
+    );
+    expect(onSwiping.mock.calls[2][0]).toEqual(
+      expect.objectContaining({ first: false })
+    );
+  });
+
   it("calls preventDefault when swiping in direction that has a callback", () => {
     const onSwipedDown = jest.fn();
 

src/index.ts

@@ -166,10 +166,11 @@ function getHandlers(
       )
         event.preventDefault();
 
-      // first is now always false
       return {
         ...state,
-        eventData: { ...eventData, first: false },
+        // first is now always false
+        first: false,
+        eventData,
         swiping: true,
       };
     });