bugfix sorting & grouping

src/pages/lesson-list.tsx

@@ -194,12 +194,13 @@ const LessonList = () => {
   const toastRef = useRef(null)
   const createdLessonRef = useRef(null)
   const [editLesson, setEditLesson] = useState<Lesson>(null)
+  const sorted = useMemo(() => [...(data?.body || [])]?.sort((a, b) => a.date < b.date ? 1 : -1), [data, data?.body])
+
   const lessonCalc = useMemo(() => {
     if (!isSuccess) {
       return []
     }
 
-    const sorted = [...data?.body].sort((a, b) => a.date > b.date ? 1 : -1)
 
     if (!groupByDate) {
       return [{ date: '', data: sorted }]
@@ -223,7 +224,7 @@ const LessonList = () => {
     }
 
     return lessonsData
-  }, [groupByDate, isSuccess])
+  }, [groupByDate, isSuccess, sorted])
 
   const onSubmit = (lessonData) => {
     toastRef.current = toast({
@@ -404,10 +405,10 @@ const LessonList = () => {
             )}
           </Box>
         )}
-        {barFeature && (
+        {barFeature && sorted?.length && (
           <Box height="300">
             <Bar
-              data={data?.body.map((lesson, index) => ({
+              data={sorted.map((lesson, index) => ({
                 lessonIndex: `#${index + 1}`,
                 count: lesson.students.length,
               }))}