Add a converter for datetime.datetime <--> Timestamp.

Signed-off-by: Michael Johansen <[email protected]>

Author: Michael Johansen

src/nipanel/_convert.py

@@ -12,6 +12,7 @@
 from nipanel.converters.builtin import (
     BoolConverter,
     BytesConverter,
+    DateTimeConverter,
     FloatConverter,
     IntConverter,
     StrConverter,
@@ -37,6 +38,7 @@
     FloatConverter(),
     IntConverter(),
     StrConverter(),
+    DateTimeConverter(),
     # Containers next
     BoolCollectionConverter(),
     BytesCollectionConverter(),

src/nipanel/converters/builtin.py

@@ -1,9 +1,10 @@
 """Classes to convert between builtin Python scalars and containers."""
 
+import datetime as dt
 from collections.abc import Collection
 from typing import Type
 
-from google.protobuf import wrappers_pb2
+from google.protobuf import timestamp_pb2, wrappers_pb2
 from ni.panels.v1 import panel_types_pb2
 
 from nipanel.converters import Converter
@@ -119,6 +120,30 @@ def to_python_value(self, protobuf_message: wrappers_pb2.StringValue) -> str:
         return protobuf_message.value
 
 
+class DateTimeConverter(Converter[dt.datetime, timestamp_pb2.Timestamp]):
+    """A converter for datetime.datetime types."""
+
+    @property
+    def python_typename(self) -> str:
+        """The Python type that this converter handles."""
+        return dt.datetime.__name__
+
+    @property
+    def protobuf_message(self) -> Type[timestamp_pb2.Timestamp]:
+        """The type-specific protobuf message for the Python type."""
+        return timestamp_pb2.Timestamp
+
+    def to_protobuf_message(self, python_value: dt.datetime) -> timestamp_pb2.Timestamp:
+        """Convert the Python dt.datetime to a protobuf timestamp_pb2.Timestamp."""
+        ts = self.protobuf_message()
+        ts.FromDatetime(python_value)
+        return ts
+
+    def to_python_value(self, protobuf_message: timestamp_pb2.Timestamp) -> dt.datetime:
+        """Convert the protobuf timestamp_pb2.Timestamp to a Python dt.datetime."""
+        return protobuf_message.ToDatetime()
+
+
 class BoolCollectionConverter(Converter[Collection[bool], panel_types_pb2.BoolCollection]):
     """A converter for a Collection of bools."""
 

tests/unit/test_convert.py

@@ -1,8 +1,9 @@
+import datetime as dt
 from typing import Any, Collection, Union
 
 import numpy as np
 import pytest
-from google.protobuf import any_pb2, wrappers_pb2
+from google.protobuf import any_pb2, timestamp_pb2, wrappers_pb2
 from google.protobuf.message import Message
 from ni.panels.v1 import panel_types_pb2
 from ni.protobuf.types.scalar_pb2 import ScalarData
@@ -53,6 +54,7 @@
         (tests.types.MixinIntEnum.VALUE11, "int"),
         (tests.types.MyStrEnum.VALUE1, "str"),
         (tests.types.MixinStrEnum.VALUE11, "str"),
+        (dt.datetime.now(), "datetime"),
         ([False, False], "Collection.bool"),
         ([b"mystr", b"mystr"], "Collection.bytes"),
         ([456.2, 1.0], "Collection.float"),
@@ -123,6 +125,16 @@ def test___python_builtin_scalar___to_any___valid_wrapperpb2_value(
     assert unpack_dest.value == expected_value
 
 
+def test___python_datetime_datetime___to_any___valid_timestamppb2_value() -> None:
+    expected_value = dt.datetime.now()
+    result = nipanel._convert.to_any(expected_value)
+    unpack_dest = timestamp_pb2.Timestamp()
+    _assert_any_and_unpack(result, unpack_dest)
+
+    assert isinstance(unpack_dest, timestamp_pb2.Timestamp)
+    assert unpack_dest.ToDatetime() == expected_value
+
+
 @pytest.mark.parametrize(
     "proto_type, default_value, expected_value",
     [
@@ -175,6 +187,18 @@ def test___wrapperpb2_value___from_any___valid_python_value(
     assert result == expected_value
 
 
+def test___timestamppb2_timestamp___from_any___valid_python_value() -> None:
+    expected_value = dt.datetime.now()
+    pb_value = timestamp_pb2.Timestamp()
+    pb_value.FromDatetime(expected_value)
+    packed_any = _pack_into_any(pb_value)
+
+    result = nipanel._convert.from_any(packed_any)
+
+    assert isinstance(result, dt.datetime)
+    assert result == expected_value
+
+
 @pytest.mark.parametrize(
     "proto_type, expected_value",
     [

tests/unit/test_streamlit_panel.py

@@ -1,5 +1,4 @@
 import enum
-from datetime import datetime
 
 import grpc
 import pytest
@@ -312,7 +311,6 @@ def test___enum_type___set_value___gets_same_value(
 @pytest.mark.parametrize(
     "value_payload",
     [
-        datetime.now(),
         lambda x: x + 1,
         [1, "string"],
         ["string", []],