Fixed issue where querying empty collection returns an empty book record

demodata.sql

@@ -130,6 +130,7 @@ INSERT INTO user_books(created_at, user_id, book_id, start_read_date, rating) VA
 INSERT INTO collections(name, user_id) VALUES ('Littérature française',(SELECT id FROM users WHERE name = 'demo'));
 INSERT INTO collections(name, user_id) VALUES ('Nouvelles',(SELECT id FROM users WHERE name = 'demo'));
 INSERT INTO collections(name, user_id) VALUES ('Non fiction',(SELECT id FROM users WHERE name = 'demo2'));
+INSERT INTO collections(name, user_id) VALUES ('Empty',(SELECT id FROM users WHERE name = 'demo'));
 
 INSERT INTO collection_books(collection_id, book_id) VALUES ((SELECT id FROM collections WHERE name = 'Littérature française'), (SELECT id FROM books WHERE title = 'Nord'));
 INSERT INTO collection_books(collection_id, book_id) VALUES ((SELECT id FROM collections WHERE name = 'Littérature française'), (SELECT id FROM books WHERE title = 'Gargantua'));

internal/adapter/adapter.go

@@ -14,7 +14,10 @@ func CollectionQueryToCollectionDto(collectionsQueryResult []query.CollectionsQu
 	var collection dto.CollectionGet
 	for _, collectionsDb := range collectionsQueryResult {
 		collection.Name = collectionsDb.Name
-		collection.Books = append(collection.Books, collectionDbToBookItem(&collectionsDb))
+		book := collectionDbToBookItem(&collectionsDb)
+		if book != nil {
+			collection.Books = append(collection.Books, *book)
+		}
 		collection.UserID = collectionsDb.UserID
 	}
 	return collection
@@ -32,17 +35,25 @@ func CollectionQueryToCollectionItemDto(collectionsQueryResult []query.Collectio
 			//current collection is the last element
 			i = len(collections) - 1
 		}
-		collections[i].Books = append(collections[i].Books, collectionDbToBookItem(&collectionDb))
+		book := collectionDbToBookItem(&collectionDb)
+		if book != nil {
+			collections[i].Books = append(collections[i].Books, *book)
+		}
 	}
 	return collections
 }
 
-func collectionDbToBookItem(collectionDb *query.CollectionsQueryResult) dto.CollectionBookItemGet {
+func collectionDbToBookItem(collectionDb *query.CollectionsQueryResult) *dto.CollectionBookItemGet {
-	return dto.CollectionBookItemGet{
+	if collectionDb.BookId > 0 {
+		bookItem := dto.CollectionBookItemGet{
 			ID:        collectionDb.BookId,
 			Title:     collectionDb.BookTitle,
 			CoverPath: collectionDb.CoverPath,
 		}
+		return &bookItem
+	} else {
+		return nil
+	}
 }
 
 // returns the position in collections, -1 if not found

internal/apitest/fetchallcollections_test.go

@@ -12,8 +12,8 @@ import (
 func TestFetchAllCollections_OK(t *testing.T) {
 	status, res := testFetchCollections(t, "10", "0")
 	assert.Equal(t, http.StatusOK, status)
-	assert.Equal(t, int64(2), res.Count)
+	assert.Equal(t, int64(3), res.Count)
-	assert.Equal(t, 2, len(res.Collections))
+	assert.Equal(t, 3, len(res.Collections))
 }
 
 func testFetchCollections(t *testing.T, limit string, offset string) (int, dto.CollectionItemsGet) {

internal/apitest/get_collection_test.go

@@ -25,10 +25,18 @@ func TestGetCollection_Limit(t *testing.T) {
 }
 
 func TestGetCollection_Unauthorized(t *testing.T) {
-	status, _ := testGetCollection(t, "4", "10", "0")
+	status, _ := testGetCollection(t, "3", "10", "0")
 	assert.Equal(t, http.StatusUnauthorized, status)
 }
 
+func TestGetCollection_Empty(t *testing.T) {
+	status, collection := testGetCollection(t, "4", "10", "0")
+	assert.Equal(t, http.StatusOK, status)
+	assert.Equal(t, "Empty", collection.Name)
+	assert.Equal(t, 0, len(collection.Books))
+	assert.Equal(t, int64(0), collection.Count)
+}
+
 func testGetCollection(t *testing.T, id string, limit string, offset string) (int, dto.CollectionGet) {
 	return testutils.TestFetchModel[dto.CollectionGet](t, "/ws/collection/"+id, limit, offset)
 }

internal/query/query.go

@@ -226,7 +226,7 @@ func FetchCollectionBooks(db *gorm.DB, collectionId uint, limit int, offset int)
 
 func FetchCollectionBooksCount(db *gorm.DB, collectionId uint) (int64, error) {
 	var count int64
-	res := fetchCollectionBooksQuery(db, collectionId).Count(&count)
+	res := fetchCollectionBooksQuery(db, collectionId).Where("book_id IS NOT NULL").Count(&count)
 	return count, res.Error
 }