Fix: handle empty string in connector comment padding (#3437)

* handle empty string in pad_comment  + staticmethod

* tests added for pad_comment

* style

* for now:
1. removing staticmethod
2. generator object only once

* style

* style

* redundant import

* test case for empty comment

* styling

sqlglot/generator.py

@@ -2845,7 +2845,8 @@ def connector_sql(
                 stack.append(expression.right)
                 if expression.comments and self.comments:
                     for comment in expression.comments:
-                        op += f" /*{self.pad_comment(comment)}*/"
+                        if comment:
+                            op += f" /*{self.pad_comment(comment)}*/"
                 stack.extend((op, expression.left))
             return op
 

tests/test_transpile.py

@@ -551,6 +551,13 @@ def test_comments(self):
             pretty=True,
         )
 
+        self.validate(
+            """SELECT X FROM  catalog.db.table WHERE Y 
+        --
+        AND Z""",
+            """SELECT X FROM catalog.db.table WHERE Y AND Z""",
+        )
+
     def test_types(self):
         self.validate("INT 1", "CAST(1 AS INT)")
         self.validate("VARCHAR 'x' y", "CAST('x' AS VARCHAR) AS y")