feat: adds the SerDeInfo class and tests (#2108)

* feat: adds SerDeInfo class and tests

* cleans up type hints and some minor tweaks

google/cloud/bigquery/schema.py

@@ -14,8 +14,10 @@
 
 """Schemas for BigQuery tables / queries."""
 
+from __future__ import annotations
 import collections
 import enum
+import typing
 from typing import Any, cast, Dict, Iterable, Optional, Union
 
 from google.cloud.bigquery import _helpers
@@ -556,3 +558,89 @@ def to_api_repr(self) -> dict:
         """
         answer = {"names": list(self.names)}
         return answer
+
+
+class SerDeInfo:
+    """Serializer and deserializer information.
+
+    Args:
+        serialization_library (str): Required. Specifies a fully-qualified class
+            name of the serialization library that is responsible for the
+            translation of data between table representation and the underlying
+            low-level input and output format structures. The maximum length is
+            256 characters.
+        name (Optional[str]): Name of the SerDe. The maximum length is 256
+            characters.
+        parameters: (Optional[dict[str, str]]): Key-value pairs that define the initialization
+            parameters for the serialization library. Maximum size 10 Kib.
+    """
+
+    def __init__(
+        self,
+        serialization_library: str,
+        name: Optional[str] = None,
+        parameters: Optional[dict[str, str]] = None,
+    ):
+        self._properties: Dict[str, Any] = {}
+        self.serialization_library = serialization_library
+        self.name = name
+        self.parameters = parameters
+
+    @property
+    def serialization_library(self) -> str:
+        """Required. Specifies a fully-qualified class name of the serialization
+        library that is responsible for the translation of data between table
+        representation and the underlying low-level input and output format
+        structures. The maximum length is 256 characters."""
+
+        return typing.cast(str, self._properties.get("serializationLibrary"))
+
+    @serialization_library.setter
+    def serialization_library(self, value: str):
+        value = _helpers._isinstance_or_raise(value, str, none_allowed=False)
+        self._properties["serializationLibrary"] = value
+
+    @property
+    def name(self) -> Optional[str]:
+        """Optional. Name of the SerDe. The maximum length is 256 characters."""
+
+        return self._properties.get("name")
+
+    @name.setter
+    def name(self, value: Optional[str] = None):
+        value = _helpers._isinstance_or_raise(value, str, none_allowed=True)
+        self._properties["name"] = value
+
+    @property
+    def parameters(self) -> Optional[dict[str, str]]:
+        """Optional. Key-value pairs that define the initialization parameters
+        for the serialization library. Maximum size 10 Kib."""
+
+        return self._properties.get("parameters")
+
+    @parameters.setter
+    def parameters(self, value: Optional[dict[str, str]] = None):
+        value = _helpers._isinstance_or_raise(value, dict, none_allowed=True)
+        self._properties["parameters"] = value
+
+    def to_api_repr(self) -> dict:
+        """Build an API representation of this object.
+        Returns:
+            Dict[str, Any]:
+                A dictionary in the format used by the BigQuery API.
+        """
+        return self._properties
+
+    @classmethod
+    def from_api_repr(cls, api_repr: dict) -> SerDeInfo:
+        """Factory: constructs an instance of the class (cls)
+        given its API representation.
+        Args:
+            resource (Dict[str, Any]):
+                API representation of the object to be instantiated.
+        Returns:
+            An instance of the class initialized with data from 'resource'.
+        """
+        config = cls("PLACEHOLDER")
+        config._properties = api_repr
+        return config

tests/unit/test_schema.py

@@ -20,6 +20,7 @@
 
 from google.cloud import bigquery
 from google.cloud.bigquery.standard_sql import StandardSqlStructType
+from google.cloud.bigquery import schema
 from google.cloud.bigquery.schema import PolicyTagList
 
 
@@ -130,8 +131,6 @@ def test_constructor_range_str(self):
         self.assertEqual(field.range_element_type.element_type, "DATETIME")
 
     def test_to_api_repr(self):
-        from google.cloud.bigquery.schema import PolicyTagList
-
         policy = PolicyTagList(names=("foo", "bar"))
         self.assertEqual(
             policy.to_api_repr(),
@@ -886,8 +885,6 @@ def test_valid_mapping_representation(self):
 class TestPolicyTags(unittest.TestCase):
     @staticmethod
     def _get_target_class():
-        from google.cloud.bigquery.schema import PolicyTagList
-
         return PolicyTagList
 
     def _make_one(self, *args, **kw):
@@ -1129,3 +1126,90 @@ def test_to_api_repr_parameterized(field, api):
     from google.cloud.bigquery.schema import SchemaField
 
     assert SchemaField(**field).to_api_repr() == api
+
+
+class TestSerDeInfo:
+    """Tests for the SerDeInfo class."""
+
+    @staticmethod
+    def _get_target_class():
+        return schema.SerDeInfo
+
+    def _make_one(self, *args, **kwargs):
+        return self._get_target_class()(*args, **kwargs)
+
+    @pytest.mark.parametrize(
+        "serialization_library,name,parameters",
+        [
+            ("testpath.to.LazySimpleSerDe", None, None),
+            ("testpath.to.LazySimpleSerDe", "serde_name", None),
+            ("testpath.to.LazySimpleSerDe", None, {"key": "value"}),
+            ("testpath.to.LazySimpleSerDe", "serde_name", {"key": "value"}),
+        ],
+    )
+    def test_ctor_valid_input(self, serialization_library, name, parameters):
+        serde_info = self._make_one(
+            serialization_library=serialization_library,
+            name=name,
+            parameters=parameters,
+        )
+        assert serde_info.serialization_library == serialization_library
+        assert serde_info.name == name
+        assert serde_info.parameters == parameters
+
+    @pytest.mark.parametrize(
+        "serialization_library,name,parameters",
+        [
+            (123, None, None),
+            ("testpath.to.LazySimpleSerDe", 123, None),
+            ("testpath.to.LazySimpleSerDe", None, ["test", "list"]),
+            ("testpath.to.LazySimpleSerDe", None, 123),
+        ],
+    )
+    def test_ctor_invalid_input(self, serialization_library, name, parameters):
+        with pytest.raises(TypeError) as e:
+            self._make_one(
+                serialization_library=serialization_library,
+                name=name,
+                parameters=parameters,
+            )
+        # Looking for the first word from the string "Pass <variable> as..."
+        assert "Pass " in str(e.value)
+
+    def test_to_api_repr(self):
+        serde_info = self._make_one(
+            serialization_library="testpath.to.LazySimpleSerDe",
+            name="serde_name",
+            parameters={"key": "value"},
+        )
+        expected_repr = {
+            "serializationLibrary": "testpath.to.LazySimpleSerDe",
+            "name": "serde_name",
+            "parameters": {"key": "value"},
+        }
+        assert serde_info.to_api_repr() == expected_repr
+
+    def test_from_api_repr(self):
+        """GIVEN an api representation of a SerDeInfo object (i.e. resource)
+        WHEN converted into a SerDeInfo object using from_api_repr()
+        THEN it will have the representation in dict format as a SerDeInfo
+        object made directly (via _make_one()) and represented in dict format.
+        """
+        api_repr = {
+            "serializationLibrary": "testpath.to.LazySimpleSerDe",
+            "name": "serde_name",
+            "parameters": {"key": "value"},
+        }
+
+        expected = self._make_one(
+            serialization_library="testpath.to.LazySimpleSerDe",
+            name="serde_name",
+            parameters={"key": "value"},
+        )
+
+        klass = self._get_target_class()
+        result = klass.from_api_repr(api_repr)
+
+        # We convert both to dict format because these classes do not have a
+        # __eq__() method to facilitate direct equality comparisons.
+        assert result.to_api_repr() == expected.to_api_repr()