chore: handle length edge cases

packages/lib/src/spatial-navigation/components/virtualizedList/helpers/getNumberOfItemsVisibleOnScreen.ts

@@ -9,16 +9,20 @@ const getMinSizeOfItems = <T>({
     return itemSize;
   }
 
-  let minSize: number | undefined = undefined;
-
-  for (let i = 0; i < data.length; i++) {
-    const item = data[i];
-    if (item !== undefined) {
-      const currentSize = itemSize(item);
-      if (minSize === undefined || currentSize < minSize) {
-        minSize = currentSize;
-      }
-    }
+  if (data.length === 0) {
+    return 0;
+  }
+
+  const firstElementSize = itemSize(data[0]);
+
+  const minSize = data.reduce<number>((smallestSize, item) => {
+    const currentSize = itemSize(item);
+    if (currentSize < smallestSize) return currentSize;
+    return smallestSize;
+  }, firstElementSize);
+
+  if (minSize === 0) {
+    console.warn('The size of the smallest item in the list is 0. The list will appear empty.');
   }
 
   return minSize;
@@ -33,11 +37,20 @@ export const getNumberOfItemsVisibleOnScreen = <T>({
   listSizeInPx: number;
   itemSize: number | ((item: T) => number);
 }) => {
+  if (data.length === 0) {
+    return 0;
+  }
+
   const itemSizeToComputeRanges = getMinSizeOfItems({ data, itemSize });
 
   if (!itemSizeToComputeRanges) {
     return 0;
   }
 
+  if (itemSizeToComputeRanges === 0) {
+    console.warn('The size of the smallest item in the list is 0. The list will appear empty.');
+    return 0;
+  }
+
   return Math.floor(listSizeInPx / itemSizeToComputeRanges);
 };