diff --git a/python/sedonadb/python/sedonadb/testing.py b/python/sedonadb/python/sedonadb/testing.py
index 990c5d940..de00446bd 100644
--- a/python/sedonadb/python/sedonadb/testing.py
+++ b/python/sedonadb/python/sedonadb/testing.py
@@ -63,6 +63,31 @@ def _env_no_skip():
     return env_no_skip in ("true", "1")
 
 
+def _normalize_geometry_wkt_columns(rows, geometry_indexes):
+    """Canonicalize WKT only for geometry-typed tuple values."""
+    import shapely
+
+    geometry_indexes = set(geometry_indexes)
+    normalized_rows = []
+
+    for row in rows:
+        normalized_row = list(row)
+
+        for i in geometry_indexes:
+            value = normalized_row[i]
+            if not isinstance(value, str):
+                continue
+
+            try:
+                normalized_row[i] = shapely.to_wkt(shapely.from_wkt(value))
+            except (ValueError, TypeError, shapely.errors.GEOSException):
+                pass
+
+        normalized_rows.append(tuple(normalized_row))
+
+    return normalized_rows
+
+
 class DBEngine:
     """Engine-agnostic catalog and SQL engine
 
@@ -288,7 +313,18 @@ def assert_result(self, result, expected, **kwargs) -> "DBEngine":
             result_pandas = self.result_to_pandas(result)
             pandas.testing.assert_frame_equal(result_pandas, expected, **kwargs)
         elif isinstance(expected, list):
+            result_table = self.result_to_table(result)
+            geometry_indexes = {
+                i
+                for i, col in enumerate(result_table.columns)
+                if _type_is_geoarrow(col.type)
+            }
             result_tuples = self.result_to_tuples(result, **kwargs)
+            if geometry_indexes:
+                result_tuples = _normalize_geometry_wkt_columns(
+                    result_tuples, geometry_indexes
+                )
+                expected = _normalize_geometry_wkt_columns(expected, geometry_indexes)
             if result_tuples != expected:
                 raise AssertionError(
                     f"Expected:\n  {expected}\nGot:\n  {result_tuples}"
diff --git a/python/sedonadb/tests/functions/test_functions.py b/python/sedonadb/tests/functions/test_functions.py
index 95c36c0ae..407d9bdad 100644
--- a/python/sedonadb/tests/functions/test_functions.py
+++ b/python/sedonadb/tests/functions/test_functions.py
@@ -1221,11 +1221,11 @@ def test_st_unaryunion_zm(eng, geom, expected):
     elif is_postgis and ("M(" in expected or "M (" in expected):
         pytest.skip("PostGIS doesn't support M dimensions")
     else:
-        # Test for exact string equality
-        # Remove all spaces from both the actual and expected results to ignore formatting differences
+        # Compare the geometry result directly so the shared test harness can
+        # normalize WKT formatting for geometry-typed outputs only.
         eng.assert_query_result(
-            f"SELECT replace(ST_AsText(ST_UnaryUnion({geom_or_null(geom)})), ' ', '')",
-            expected.replace(" ", ""),
+            f"SELECT ST_UnaryUnion({geom_or_null(geom)})",
+            expected,
         )
 
 
@@ -2309,7 +2309,7 @@ def test_st_length(eng, geom, expected):
     ("geom", "expected"),
     [
         (None, None),
-        ("POINT EMPTY", "POINT EMPTY"),
+        ("POINT EMPTY", "POINT (nan nan)"),
         ("LINESTRING EMPTY", "LINESTRING EMPTY"),
         ("POLYGON EMPTY", "POLYGON EMPTY"),
         ("MULTIPOINT EMPTY", "MULTIPOINT EMPTY"),
@@ -2371,20 +2371,12 @@ def test_st_normalize(eng, geom, expected):
             expected = "POLYGON Z ((0 0 5, 0 1 5, 1 1 5, 1 0 5, 0 0 5))"
 
     if isinstance(eng, PostGIS) and expected is not None:
-        # Normalize expected WKT to PostGIS's compact ST_AsText formatting.
-        expected = expected.replace(", ", ",")
-        expected = expected.replace(" (", "(")
+        # Normalize expected WKT to PostGIS's formatting.
         expected = expected.replace(r"ZM(", r"ZM (")
         expected = expected.replace(r"M(", r"M (")
         expected = expected.replace(r"Z(", r"Z (")
 
-    if isinstance(eng, SedonaDB) and expected is not None:
-        expected = expected.replace(", ", ",")
-        expected = expected.replace(" (", "(")
-
-    eng.assert_query_result(
-        f"SELECT ST_AsText(ST_Normalize({geom_or_null(geom)}))", expected
-    )
+    eng.assert_query_result(f"SELECT ST_Normalize({geom_or_null(geom)})", expected)
 
 
 @pytest.mark.parametrize("eng", [SedonaDB, PostGIS])
diff --git a/python/sedonadb/tests/test_testing.py b/python/sedonadb/tests/test_testing.py
index 42edf1f6d..9fbdf4269 100644
--- a/python/sedonadb/tests/test_testing.py
+++ b/python/sedonadb/tests/test_testing.py
@@ -129,6 +129,21 @@ def test_assert_result_spatial(eng):
             )
 
 
+@pytest.mark.parametrize("eng", [SedonaDB, PostGIS, DuckDB])
+def test_assert_result_wkt_normalizes_geometry_only(eng):
+    with eng.create_or_skip() as eng:
+        eng.assert_query_result(
+            "SELECT ST_GeomFromText('POLYGON Z ((0 0 5, 0 1 5, 1 1 5, 1 0 5, 0 0 5))') as geom",
+            "POLYGON Z ((0 0 5,0 1 5,1 1 5,1 0 5,0 0 5))",
+        )
+
+        with pytest.raises(AssertionError):
+            eng.assert_query_result(
+                "SELECT 'POLYGON Z ((0 0 5, 0 1 5, 1 1 5, 1 0 5, 0 0 5))' as geom",
+                "POLYGON Z ((0 0 5,0 1 5,1 1 5,1 0 5,0 0 5))",
+            )
+
+
 @pytest.mark.parametrize("eng", [SedonaDB, PostGIS, DuckDB])
 def test_table_arrow_no_crs(eng):
     with eng.create_or_skip() as eng: