fix: pagination offset when filtering without key

types/query/collections_pagination.go

@@ -128,13 +128,10 @@ func collFilteredPaginateNoKey[K, V any, C Collection[K, V], T any](
 		return nil, nil, err
 	}
 	defer iterator.Close()
-	// we advance the iter equal to the provided offset
-	if !advanceIter(iterator, offset) {
-		return nil, nil, collections.ErrInvalidIterator
-	}
 
 	var (
 		count   uint64
+		skipped uint64
 		nextKey []byte
 		results []T
 	)
@@ -149,6 +146,11 @@ func collFilteredPaginateNoKey[K, V any, C Collection[K, V], T any](
 			}
 			// if no predicate function is specified then we just include the result
 			if predicateFunc == nil {
+				if skipped < offset {
+					skipped++
+					continue
+				}
+
 				transformed, err := transformFunc(kv.Key, kv.Value)
 				if err != nil {
 					return nil, nil, err
@@ -163,6 +165,12 @@ func collFilteredPaginateNoKey[K, V any, C Collection[K, V], T any](
 					return nil, nil, err
 				}
 				if include {
+					// Item matches filter - check if we need to skip it for offset
+					if skipped < offset {
+						skipped++
+						continue
+					}
+
 					transformed, err := transformFunc(kv.Key, kv.Value)
 					if err != nil {
 						return nil, nil, err
@@ -224,20 +232,6 @@ func collFilteredPaginateNoKey[K, V any, C Collection[K, V], T any](
 	return results, resp, nil
 }
 
-func advanceIter[I interface {
-	Next()
-	Valid() bool
-}](iter I, offset uint64,
-) bool {
-	for i := uint64(0); i < offset; i++ {
-		if !iter.Valid() {
-			return false
-		}
-		iter.Next()
-	}
-	return true
-}
-
 // collFilteredPaginateByKey paginates a collection when a starting key
 // is provided in the PageRequest. Predicate is applied only if not nil.
 func collFilteredPaginateByKey[K, V any, C Collection[K, V], T any](

types/query/collections_pagination_test.go

@@ -156,11 +156,13 @@ func TestCollectionPagination(t *testing.T) {
 		},
 		"filtered with offset": {
 			req: &PageRequest{
-				Offset: 3,
-				Limit:  3,
+				Offset:     3,
+				Limit:      3,
+				CountTotal: true,
 			},
 			expResp: &PageResponse{
 				NextKey: encodeKey(12),
+				Total:   150,
 			},
 			filter: func(key, value uint64) (bool, error) {
 				return key%2 == 0, nil