Merge pull request #3666 from fable-compiler/python-datetime-timespan…

…-addition

src/Fable.Cli/CHANGELOG.md

@@ -21,6 +21,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * [GH-3655](https://github.com/fable-compiler/Fable/issues/3655) Fix for Python output file names (by @dbrattli)
 * [GH-3660](https://github.com/fable-compiler/Fable/issues/3660) Fix for decimal to string with culture (by @dbrattli)
+* [GH-3666](https://github.com/fable-compiler/Fable/pull/3666) Fix for `DateTime` and `TimeSpan` addition (by @dbrattli)
 
 ## 4.8.1 - 2023-12-12
 

src/fable-library-py/fable_library/date.py

@@ -60,6 +60,10 @@ def year(d: datetime) -> int:
     return d.year
 
 
+def to_universal_time(d: datetime) -> datetime:
+    return d.astimezone(timezone.utc)
+
+
 def date_to_string_with_custom_format(date: datetime, format: str, utc: bool) -> str:
     def match(match: Match[str]) -> str:
         group = match.group()
@@ -219,8 +223,12 @@ def min_value() -> datetime:
     return datetime.min
 
 
-def op_addition(x: datetime, y: timedelta) -> datetime:
-    return x + y
+def op_addition(x: datetime, y: TimeSpan) -> datetime:
+    return x + timedelta(microseconds=total_microseconds(y))
+
+
+def add(x: datetime, y: TimeSpan) -> datetime:
+    return op_addition(x, y)
 
 
 def parse(string: str, detectUTC: bool = False) -> datetime:
@@ -242,6 +250,7 @@ def add_milliseconds(d: datetime, v: int) -> datetime:
 
 
 __all__ = [
+    "add",
     "op_subtraction",
     "subtract",
     "create",
@@ -259,5 +268,6 @@ def add_milliseconds(d: datetime, v: int) -> datetime:
     "min_value",
     "op_addition",
     "parse",
+    "to_universal_time",
     "try_parse",
 ]

src/fable-library-py/fable_library/map_util.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import re
-from collections.abc import ByteString, Iterable, MutableSequence
+from collections.abc import Iterable
 from enum import IntEnum
 from re import Match
 from typing import (
@@ -12,6 +12,7 @@
 )
 
 from .types import FSharpRef, Union
+from .util import Array
 
 
 _K = TypeVar("_K")
@@ -124,7 +125,7 @@ def assign(key: str, case_rule: CaseRules, value: Any):
             kv_pair = name if len(kv_pair.fields) == 0 else [name, *kv_pair.fields]
             case_rule = defined_case_rule
 
-        if isinstance(kv_pair, list | MutableSequence | ByteString):
+        if isinstance(kv_pair, Array):
             length = len(kv_pair)
             if length == 0:
                 fail(kv_pair)

tests/Python/TestTimeSpan.fs

@@ -124,6 +124,19 @@ let ``test TimeSpan Addition works`` () =
     test -2000. 0. -2000.
     test 0. 0. 0.
 
+[<Fact>]
+let ``test DateTime and TimeSpan Addition works`` () =
+    let test ms expected =
+        let dt = DateTime(2014,9,12,0,0,0,DateTimeKind.Utc)
+        let ts = TimeSpan.FromMilliseconds(ms)
+        let res1 = dt.Add(ts).ToUniversalTime()
+        let res2 = (dt + ts).ToUniversalTime()
+        equal true (res1 = res2)
+        equal expected res1
+
+    DateTime(2014,9,12,0,0,1,DateTimeKind.Utc) |> test 1000.
+    DateTime(2014,9,11,23,59,59,DateTimeKind.Utc) |> test -1000.
+
 [<Fact>]
 let ``test TimeSpan implementation coherence`` () =
     TimeSpan.FromTicks(1L).Ticks |> equal 1L