From 2704474f08f65b0cec079c2309d59299b91b0f82 Mon Sep 17 00:00:00 2001
From: Giampaolo Bellavite <gpbellavite@gmail.com>
Date: Mon, 5 Mar 2018 10:10:21 +0100
Subject: [PATCH 1/2] Call `onDayChange` with `undefined` when day is not valid

---
 src/DayPickerInput.js | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/DayPickerInput.js b/src/DayPickerInput.js
index 1f6d208de0..aaebeaae94 100644
--- a/src/DayPickerInput.js
+++ b/src/DayPickerInput.js
@@ -322,14 +322,13 @@ export default class DayPickerInput extends React.Component {
     const { value } = e.target;
     if (value.trim() === '') {
       this.setState({ value });
-      if (onDayChange) {
-        onDayChange(undefined, {});
-      }
+      if (onDayChange) onDayChange(undefined, {});
       return;
     }
     const day = parseDate(value, format, dayPickerProps.locale);
     if (!day) {
       this.setState({ value });
+      if (onDayChange) onDayChange(undefined, {});
       return;
     }
     this.updateState(day, value);

From a66eab24a985e981c5544ec5a93f82878c447146 Mon Sep 17 00:00:00 2001
From: Giampaolo Bellavite <gpbellavite@gmail.com>
Date: Mon, 5 Mar 2018 10:14:57 +0100
Subject: [PATCH 2/2] Fix unit test

---
 test/daypickerinput/events.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/daypickerinput/events.js b/test/daypickerinput/events.js
index 656836a1ec..9abf7c61d9 100644
--- a/test/daypickerinput/events.js
+++ b/test/daypickerinput/events.js
@@ -107,12 +107,12 @@ describe('DayPickerInput', () => {
         input.simulate('change', { target: { value: 'foo' } });
         expect(wrapper.find('input')).toHaveProp('value', 'foo');
       });
-      it('should not call `onDayChange` if the value is not a valid date', () => {
+      it('should call `onDayChange` with `undefined` if the value is not a valid date', () => {
         const onDayChange = jest.fn();
         const wrapper = mount(<DayPickerInput onDayChange={onDayChange} />);
         const input = wrapper.find('input');
         input.simulate('change', { target: { value: 'foo' } });
-        expect(onDayChange).not.toHaveBeenCalled();
+        expect(onDayChange).toHaveBeenCalledWith(undefined, {});
       });
       it("should update the input's value and the displayed month", () => {
         const wrapper = mount(<DayPickerInput />);