SNOW-3309660: Fix XML tests to run in Snowfort (#4200)

Author: sfc-gh-mayliu

CHANGELOG.md

@@ -9,6 +9,7 @@
 #### Bug Fixes
 
 - Fixed a bug where using parameter bindings for `CALL` queries issued through `session.sql` would raise an error.
+- Fixed a bug where `StringType` columns from Iceberg tables were not recognized as max-size strings.
 
 ## 1.50.0 (2026-04-23)
 

src/snowflake/snowpark/_internal/type_utils.py

@@ -278,7 +278,11 @@ def convert_sf_to_sp_type(
             )
     if column_type_name == "TEXT":
         if internal_size > 0:
-            return StringType(internal_size, internal_size == max_string_size)
+            return StringType(
+                internal_size,
+                internal_size == max_string_size
+                or internal_size == _MAX_ICEBERG_STRING_SIZE,
+            )
         elif internal_size == 0:
             return StringType()
         raise ValueError("Negative value is not a valid input for StringType")

tests/integ/test_xml_reader_row_tag.py

@@ -232,9 +232,11 @@ def test_read_xml_row_tag(
     session, file, row_tag, expected_row_count, expected_column_count
 ):
     df = session.read.option("rowTag", row_tag).xml(f"@{tmp_stage_name}/{file}")
-    result = df.collect()
-    assert len(result) == expected_row_count
-    assert len(result[0]) == expected_column_count
+    # Use count() + len(df.columns) instead of collect() to avoid materializing
+    # large result sets (e.g. 740 rows) that trigger paginated download URLs
+    # unsupported by StoredProcRestfulSession inside a stored procedure.
+    assert df.count() == expected_row_count
+    assert len(df.columns) == expected_column_count
 
 
 def test_read_xml_no_xxe(session):

tests/unit/test_types.py

@@ -53,6 +53,7 @@
     split_top_level_comma_fields,
     type_string_to_type_object,
     find_top_level_colon,
+    _MAX_ICEBERG_STRING_SIZE,
 )
 from snowflake.snowpark.types import (
     ArrayType,
@@ -1044,6 +1045,25 @@ def test_convert_sf_to_sp_type_internal_size():
     assert snowpark_type.length == 16777216
     assert snowpark_type._is_max_size
 
+    # Iceberg deployments report internal_size=134217728 for max-length strings,
+    # which differs from the regular max_string_size (16777216). This must still
+    # be recognized as a max-size string so that StringType(134217728) == StringType().
+    snowpark_type = convert_sf_to_sp_type(
+        "TEXT", 0, 0, _MAX_ICEBERG_STRING_SIZE, 16777216
+    )
+    assert isinstance(snowpark_type, StringType)
+    assert snowpark_type.length == _MAX_ICEBERG_STRING_SIZE
+    assert snowpark_type._is_max_size
+    assert snowpark_type == StringType()
+
+    snowpark_type = convert_sf_to_sp_type(
+        "TEXT", 0, 0, _MAX_ICEBERG_STRING_SIZE, _MAX_ICEBERG_STRING_SIZE
+    )
+    assert isinstance(snowpark_type, StringType)
+    assert snowpark_type.length == _MAX_ICEBERG_STRING_SIZE
+    assert snowpark_type._is_max_size
+    assert snowpark_type == StringType()
+
     with pytest.raises(
         ValueError, match="Negative value is not a valid input for StringType"
     ):