fix(graph): Support DATE type (#150)

Co-authored-by: Averi Kitsch <akitsch@google.com>

Author: mtyin

src/langchain_google_spanner/type_utils.py

@@ -62,6 +62,8 @@ def spanner_type_to_schema_str(
             return "TIMESTAMP"
         if t.code == param_types.TypeCode.JSON:
             return "JSON"
+        if t.code == param_types.TypeCode.DATE:
+            return "DATE"
         raise ValueError("Unsupported type: %s" % t)
 
     @staticmethod
@@ -90,6 +92,8 @@ def schema_str_to_spanner_type(s: str) -> param_types.Type:
             return param_types.TIMESTAMP
         if s == "JSON":
             return param_types.JSON
+        if s == "DATE":
+            return param_types.DATE
         if s.startswith("ARRAY<") and s.endswith(">"):
             return param_types.Array(
                 TypeUtility.schema_str_to_spanner_type(s[len("ARRAY<") : -len(">")])
@@ -118,6 +122,8 @@ def value_to_param_type(v: Any) -> param_types.Type:
             return param_types.FLOAT64
         if isinstance(v, datetime.datetime):
             return param_types.TIMESTAMP
+        if isinstance(v, datetime.date):
+            return param_types.DATE
         if isinstance(v, JsonObject):
             return param_types.JSON
         if isinstance(v, list):
@@ -145,6 +151,8 @@ def value_for_json(v: Any) -> Any:
             return base64.b64encode(v).decode("utf-8")
         if isinstance(v, datetime.datetime):
             return str(v)
+        if isinstance(v, datetime.date):
+            return str(v)
         if isinstance(v, JsonObject):
             return v
         if isinstance(v, list):

tests/integration/test_spanner_graph_store.py

@@ -60,6 +60,10 @@ def random_timestamp():
     return datetime.datetime.fromtimestamp(random_int(0, 366 * 24 * 60 * 60 * 1000))
 
 
+def random_date():
+    return datetime.date.fromtimestamp(random_int(0, 366 * 24 * 60 * 60 * 1000))
+
+
 def random_param():
     # None param is not supported.
     return random.choice(random_generators())() or random_param()
@@ -86,6 +90,7 @@ def random_primitive_generators():
         random_bool,
         random_float,
         random_timestamp,
+        random_date,
     ]