Fix(snowflake): emit proper HANDLER property syntax

Author: georgesittas

sqlglot/generators/snowflake.py

@@ -481,6 +481,7 @@ class SnowflakeGenerator(generator.Generator):
         ),
         exp.CosineDistance: rename_func("VECTOR_COSINE_SIMILARITY"),
         exp.EuclideanDistance: rename_func("VECTOR_L2_DISTANCE"),
+        exp.HandlerProperty: lambda self, e: f"HANDLER = {self.sql(e, 'this')}",
         exp.FileFormatProperty: lambda self, e: (
             f"FILE_FORMAT=({self.expressions(e, 'expressions', sep=' ')})"
         ),

tests/dialects/test_snowflake.py

@@ -4419,6 +4419,10 @@ def test_user_defined_functions(self):
             },
         )
 
+        self.validate_identity(
+            "CREATE OR REPLACE FUNCTION repro_fn() RETURNS INT LANGUAGE PYTHON HANDLER = 'fn' RUNTIME_VERSION='3.11' PACKAGES=() AS '\\ndef fn():\\n    return 1\\n'"
+        )
+
     def test_stored_procedures(self):
         self.validate_identity("CALL a.b.c(x, y)", check_command_warning=True)
         self.validate_identity(