fix(Commons): improve pagination bounds checking

server/api/books.ts

@@ -910,9 +910,17 @@ async function getCommonsCatalog(
     });
 
     const totalNumBooks = resultBooks.length;
-    const offset = getRandomOffset(totalNumBooks);
+    const offset = getRandomOffset(totalNumBooks, limit);
 
-    const randomized = resultBooks.slice(offset, offset + limit);
+    const upperBound = () => {
+      if((offset + limit) > totalNumBooks) {
+        return totalNumBooks;
+      } else {
+        return offset + limit;
+      }
+    }
+
+    const randomized = resultBooks.slice(offset, upperBound());
 
     return res.send({
       err: false,

server/api/projectfiles.ts

@@ -1139,9 +1139,16 @@ async function getPublicProjectFiles(
     ]);
 
     const totalCount = aggRes.length;
-    const offset = getRandomOffset(totalCount);
+    const offset = getRandomOffset(totalCount, limit);
 
-    const paginatedRes = aggRes.slice(offset, offset + limit);
+    const upperBound = () => {
+      if((offset + limit) > totalCount) {
+        return totalCount;
+      }
+      return offset + limit;
+    }
+
+    const paginatedRes = aggRes.slice(offset, upperBound());
 
     return res.send({
       err: false,

server/util/helpers.js

@@ -318,12 +318,17 @@ export function getPaginationOffset(page, offsetMultiplier = 25) {
 }
 
 /**
- * Generates a random number between 0 and max
- * @param {Number} max - The maximum number to generate a random offset for 
+ * Generates a random number between 0 and a given limit
+ * @param {Number} total - The maximum number to generate a random number for
+ * @param {Number} limit - The limit for the random number 
  * @returns {Number} - A random number between 0 and max
  */
-export function getRandomOffset(max){
-  return Math.floor(Math.random() * max);
+export function getRandomOffset(total, limit) {
+  if (total <= limit) {
+    return 0;
+  }
+  const maxOffset = Math.max(0, total - limit);
+  return Math.floor(Math.random() * maxOffset);
 }
 
 /**