feat(DatePicker): make onChange and value required

src/components/Datepicker/Datepicker.jsx

@@ -385,10 +385,23 @@ DatePicker.propTypes = {
     PropTypes.object,
     PropTypes.number,
   ]),
-  value: PropTypes.oneOfType([PropTypes.array, PropTypes.object]),
+  value: PropTypes.oneOfType([PropTypes.array, PropTypes.object]).isRequired,
   isRange: PropTypes.bool,
   lang: PropTypes.oneOfType([PropTypes.array, PropTypes.object]),
-  onChange: PropTypes.func,
+  onChange: function (props, propName) {
+    var fn = props[propName];
+    if (
+      !fn ||
+      !fn.prototype ||
+      typeof fn.prototype.constructor !== "function" ||
+      fn.prototype.constructor.length < 2 ||
+      fn.prototype.constructor.length > 3
+    ) {
+      return new Error(
+        `${propName} must be a function with 2 (if isMonthsMode is on) or 3 args. Args are: year, month and day.`
+      );
+    }
+  },
   onYearChange: PropTypes.func,
   onShow: PropTypes.func,
   onDismiss: PropTypes.func,
@@ -401,7 +414,6 @@ DatePicker.propTypes = {
 
 DatePicker.defaultProps = {
   years: getYearsByNum(5),
-  onChange(year, month, idx) {},
   show: false,
   isMonthsMode: false,
   isRange: false,