refactor(touchCoods): extract repeated touches/chagnedTouches lookup

Author: randym

src/shared/utils/index.js

@@ -1,3 +1,4 @@
 export {default as closest} from './closest';
 export {default as requestNextAnimationFrame} from './requestNextAnimationFrame';
 export {default as distance} from './distance';
+export {default as touchCoords} from './touchCoords';

src/shared/utils/touchCoords/index.js

@@ -0,0 +1,3 @@
+import touchCoords from './touchCoords';
+
+export default touchCoords;

src/shared/utils/touchCoords/touchCoords.js

@@ -0,0 +1,9 @@
+/**
+ * Returns the first touch event found in touches or changedTouches of a touch events.
+ * @param {TouchEvent} event a touch event
+ * @return {Touch} a touch object
+ */
+export default function touchCoords(event = {}) {
+  const {touches, changedTouches} = event;
+  return (touches && touches[0]) || (changedTouches && changedTouches[0]);
+}