Performance : limit rerender of calendar

[matthieuMay]

Description

On first render Calendar components render twice. This is due to a re-parse of current month made in a useEffect

Expected Behavior

Only one render when data do not change

Fix

The re-render can be fixed by applying this patch-package:

diff --git a/node_modules/react-native-calendars/src/calendar/index.js b/node_modules/react-native-calendars/src/calendar/index.js
index 6f46e8a..45f0104 100644
--- a/node_modules/react-native-calendars/src/calendar/index.js
+++ b/node_modules/react-native-calendars/src/calendar/index.js
@@ -28,7 +28,10 @@ const Calendar = (props) => {
     const weekNumberMarking = useRef({ disabled: true, disableTouchEvent: true });
     useEffect(() => {
         if (initialDate) {
-            setCurrentMonth(parseDate(initialDate));
+            const parsed = parseDate(initialDate);
+            if (currentMonth.getTime() !== parsed.getTime()) {
+                setCurrentMonth(parseDate(initialDate));
+            }
         }
     }, [initialDate]);
     useDidUpdate(() => {