Parquet options should be reflected in options

google/cloud/bigquery/external_config.py

@@ -799,15 +799,16 @@ def parquet_options(self):
         See:
         https://cloud.google.com/bigquery/docs/reference/rest/v2/tables#ExternalDataConfiguration.FIELDS.parquet_options
         """
-        prop = self._properties.get("parquetOptions")
-        if prop is not None:
-            prop = ParquetOptions.from_api_repr(prop)
-        return prop
+        if self.source_format != ExternalSourceFormat.PARQUET:
+            return None
+        return self._options
 
     @parquet_options.setter
     def parquet_options(self, value):
-        prop = value.to_api_repr() if value is not None else None
-        self._properties["parquetOptions"] = prop
+        if self.source_format != ExternalSourceFormat.PARQUET:
+            msg = f"Cannot set Parquet options, source format is {self.source_format}"
+            raise TypeError(msg)
+        self._options = value
 
     def to_api_repr(self) -> dict:
         """Build an API representation of this object.

tests/unit/test_external_config.py

@@ -425,6 +425,57 @@ def test_to_api_repr_bigtable(self):
 
         self.assertEqual(got_resource, exp_resource)
 
+    def test_parquet_options_getter(self):
+        from google.cloud.bigquery.format_options import ParquetOptions
+
+        parquet_options = ParquetOptions.from_api_repr(
+            {"enumAsString": True, "enableListInference": False}
+        )
+        ec = external_config.ExternalConfig(
+            external_config.ExternalSourceFormat.PARQUET
+        )
+
+        self.assertIsNone(ec.parquet_options.enum_as_string)
+        self.assertIsNone(ec.parquet_options.enable_list_inference)
+
+        ec._options = parquet_options
+
+        self.assertTrue(ec.parquet_options.enum_as_string)
+        self.assertFalse(ec.parquet_options.enable_list_inference)
+
+        self.assertIs(ec.parquet_options, ec.options)
+
+    def test_parquet_options_getter_non_parquet_format(self):
+        ec = external_config.ExternalConfig(external_config.ExternalSourceFormat.CSV)
+        self.assertIsNone(ec.parquet_options)
+
+    def test_parquet_options_setter(self):
+        from google.cloud.bigquery.format_options import ParquetOptions
+
+        parquet_options = ParquetOptions.from_api_repr(
+            {"enumAsString": False, "enableListInference": True}
+        )
+        ec = external_config.ExternalConfig(
+            external_config.ExternalSourceFormat.PARQUET
+        )
+
+        ec.parquet_options = parquet_options
+
+        # Setting Parquet options should be reflected in the generic options attribute.
+        self.assertFalse(ec.options.enum_as_string)
+        self.assertTrue(ec.options.enable_list_inference)
+
+    def test_parquet_options_setter_non_parquet_format(self):
+        from google.cloud.bigquery.format_options import ParquetOptions
+
+        parquet_options = ParquetOptions.from_api_repr(
+            {"enumAsString": False, "enableListInference": True}
+        )
+        ec = external_config.ExternalConfig(external_config.ExternalSourceFormat.CSV)
+
+        with self.assertRaisesRegex(TypeError, "Cannot set.*source format is CSV"):
+            ec.parquet_options = parquet_options
+
     def test_from_api_repr_parquet(self):
         from google.cloud.bigquery.format_options import ParquetOptions