Merge pull request #198 from FormidableLabs/v6-starting-edges-at-zero

V6 starting edges at zero

.gitignore

@@ -6,3 +6,4 @@ lib
 dist
 examples/static
 coverage
+package-lock.json

__tests__/useSwipeable.spec.tsx

@@ -79,6 +79,23 @@ describe("useSwipeable", () => {
     defaultPrevented = 0;
   });
 
+  it("handles touch events that start at clientX or clientY 0", () => {
+    const swipeFuncs = getMockedSwipeFunctions();
+    const { getByText } = render(<SwipeableUsingHook {...swipeFuncs} />);
+
+    const touchArea = getByText(TESTING_TEXT);
+
+    fireEvent[TS](touchArea, cte({ x: 0, y: 100 }));
+    fireEvent[TM](touchArea, cte({ x: 0, y: 125 }));
+    fireEvent[TE](touchArea, cte({}));
+    fireEvent[TS](touchArea, cte({ x: 100, y: 0 }));
+    fireEvent[TM](touchArea, cte({ x: 125, y: 0 }));
+    fireEvent[TE](touchArea, cte({}));
+
+    expect(swipeFuncs.onSwiping).toHaveBeenCalledTimes(2);
+    expect(swipeFuncs.onSwiped).toHaveBeenCalledTimes(2);
+  });
+
   it("handles touch events and fires correct props", () => {
     const swipeFuncs = getMockedSwipeFunctions();
     const { getByText } = render(<SwipeableUsingHook {...swipeFuncs} />);

src/index.ts

@@ -166,11 +166,9 @@ function getHandlers(
 
   const onMove = (event: HandledEvents) => {
     set((state, props) => {
-      if (
-        !state.xy[0] ||
-        !state.xy[1] ||
-        ("touches" in event && event.touches.length > 1)
-      ) {
+      // Discount a swipe if additional touches are present after
+      // a swipe has started.
+      if ("touches" in event && event.touches.length > 1) {
         return state;
       }
       const { clientX, clientY } =