fix: handle cases where there are no stored columns in search indexes

src/main/java/com/google/cloud/solutions/spannerddl/parser/ASTcreate_search_index_statement.java

@@ -205,22 +205,31 @@ private void generateAlterStatementsFor(
     // Look for differences in storedColumnList
     // Easiest is to use Maps.difference, but first we need some maps, and we need to preserve order
     // so convert the keyParts to String, and then add to a LinkedHashMap.
+    ASTstored_column_list origStoredColList =
+        getOptionalChildByType(original.children, ASTstored_column_list.class);
     Map<String, ASTstored_column> originalStoredColumns =
-        getChildByType(original.children, ASTstored_column_list.class).getStoredColumns().stream()
-            .collect(
-                Collectors.toMap(
-                    ASTstored_column::toString,
-                    Function.identity(),
-                    (x, y) -> y,
-                    LinkedHashMap::new));
+        origStoredColList == null
+            ? Map.of()
+            : origStoredColList.getStoredColumns().stream()
+                .collect(
+                    Collectors.toMap(
+                        ASTstored_column::toString,
+                        Function.identity(),
+                        (x, y) -> y,
+                        LinkedHashMap::new));
+
+    ASTstored_column_list newStoredColList =
+        getOptionalChildByType(other.children, ASTstored_column_list.class);
     Map<String, ASTstored_column> newStoredColumns =
-        getChildByType(other.children, ASTstored_column_list.class).getStoredColumns().stream()
-            .collect(
-                Collectors.toMap(
-                    ASTstored_column::toString,
-                    Function.identity(),
-                    (x, y) -> y,
-                    LinkedHashMap::new));
+        newStoredColList == null
+            ? Map.of()
+            : newStoredColList.getStoredColumns().stream()
+                .collect(
+                    Collectors.toMap(
+                        ASTstored_column::toString,
+                        Function.identity(),
+                        (x, y) -> y,
+                        LinkedHashMap::new));
     MapDifference<String, ASTstored_column> storedColDiff =
         Maps.difference(originalStoredColumns, newStoredColumns);
 

src/test/resources/ddlParserValidation.txt

@@ -149,5 +149,6 @@ OPTIONS (sort_order_sharding=TRUE)
 
 CREATE SEARCH INDEX AlbumsIndex
 ON Albums ( AlbumTitle_Tokens ASC )
+OPTIONS (sort_order_sharding=TRUE)
 
 ==

src/test/resources/expectedDdlDiff.txt

@@ -313,4 +313,18 @@ ALTER TABLE test1 ADD COLUMN col3 INT64
 ALTER SEARCH INDEX AlbumsIndex ADD COLUMN col3 ASC
 ALTER SEARCH INDEX AlbumsIndex ADD STORED COLUMN scol3
 
+== TEST 58 Add col to search index - no stored columns
+
+ALTER SEARCH INDEX AlbumsIndex ADD COLUMN col3 ASC
+
+== TEST 59 Add stored col to search index
+
+ALTER SEARCH INDEX AlbumsIndex ADD STORED COLUMN scol1
+
+== TEST 60 Remove stored cols from search index
+
+ALTER SEARCH INDEX AlbumsIndex DROP STORED COLUMN scol1
+
 ==
+
+

src/test/resources/newDdl.txt

@@ -489,4 +489,21 @@ CREATE SEARCH INDEX AlbumsIndex
 ON Albums (col1, col3)
 STORING (scol1, scol3);
 
+== TEST 58 Add col to search index - no stored columns
+
+CREATE SEARCH INDEX AlbumsIndex
+ON Albums (col1, col2, col3)
+
+== TEST 59 Add stored col to search index
+
+CREATE SEARCH INDEX AlbumsIndex
+ON Albums (col1, col2)
+STORING (scol1);
+
+== TEST 60 Remove stored cols from search index
+
+CREATE SEARCH INDEX AlbumsIndex
+ON Albums (col1, col2)
+
 ==
+

src/test/resources/originalDdl.txt

@@ -487,6 +487,25 @@ CREATE SEARCH INDEX AlbumsIndex
 ON Albums (col1, col2)
 STORING (scol1, scol2);
 
+== TEST 58 Add col to search index - no stored columns
+
+CREATE SEARCH INDEX AlbumsIndex
+ON Albums (col1, col2)
+
+== TEST 59 Add stored col to search index
+
+CREATE SEARCH INDEX AlbumsIndex
+ON Albums (col1, col2)
+
+== TEST 60 Remove stored cols from search index
+
+CREATE SEARCH INDEX AlbumsIndex
+ON Albums (col1, col2)
+STORING (scol1)
+
 ==
 
 
+
+
+