fix(vars): compare timezone-aware datetimes by instant

packages/reflex-base/news/6755.bugfix.md

@@ -0,0 +1 @@
+Compare timezone-aware datetime Vars by their instants instead of their serialized UTC offsets.

packages/reflex-base/src/reflex_base/vars/datetime.py

@@ -36,6 +36,34 @@ def raise_var_type_error():
 class DateTimeVar(Var[DATETIME_T], python_types=(datetime, date)):
     """A variable that holds a datetime or date object."""
 
+    __hash__ = Var.__hash__
+
+    def __eq__(self, other: Any) -> BooleanVar:
+        """Equal comparison.
+
+        Args:
+            other: The other datetime to compare.
+
+        Returns:
+            The result of the comparison.
+        """
+        if not isinstance(other, DATETIME_TYPES):
+            return super().__eq__(other)
+        return date_eq_operation(self, other)
+
+    def __ne__(self, other: Any) -> BooleanVar:
+        """Not equal comparison.
+
+        Args:
+            other: The other datetime to compare.
+
+        Returns:
+            The result of the comparison.
+        """
+        if not isinstance(other, DATETIME_TYPES):
+            return super().__ne__(other)
+        return date_ne_operation(self, other)
+
     def __lt__(self, other: datetime_types | DateTimeVar) -> BooleanVar:
         """Less than comparison.
 
@@ -89,6 +117,34 @@ def __ge__(self, other: datetime_types | DateTimeVar) -> BooleanVar:
         return date_ge_operation(self, other)
 
 
+@var_operation
+def date_eq_operation(lhs: DateTimeVar | Any, rhs: DateTimeVar | Any):
+    """Equal comparison.
+
+    Args:
+        lhs: The left-hand side of the operation.
+        rhs: The right-hand side of the operation.
+
+    Returns:
+        The result of the operation.
+    """
+    return date_compare_operation(lhs, rhs, "===")
+
+
+@var_operation
+def date_ne_operation(lhs: DateTimeVar | Any, rhs: DateTimeVar | Any):
+    """Not equal comparison.
+
+    Args:
+        lhs: The left-hand side of the operation.
+        rhs: The right-hand side of the operation.
+
+    Returns:
+        The result of the operation.
+    """
+    return date_compare_operation(lhs, rhs, "!==")
+
+
 @var_operation
 def date_gt_operation(lhs: DateTimeVar | Any, rhs: DateTimeVar | Any):
     """Greater than comparison.
@@ -100,7 +156,7 @@ def date_gt_operation(lhs: DateTimeVar | Any, rhs: DateTimeVar | Any):
     Returns:
         The result of the operation.
     """
-    return date_compare_operation(rhs, lhs, strict=True)
+    return date_compare_operation(lhs, rhs, ">")
 
 
 @var_operation
@@ -114,7 +170,7 @@ def date_lt_operation(lhs: DateTimeVar | Any, rhs: DateTimeVar | Any):
     Returns:
         The result of the operation.
     """
-    return date_compare_operation(lhs, rhs, strict=True)
+    return date_compare_operation(lhs, rhs, "<")
 
 
 @var_operation
@@ -128,7 +184,7 @@ def date_le_operation(lhs: DateTimeVar | Any, rhs: DateTimeVar | Any):
     Returns:
         The result of the operation.
     """
-    return date_compare_operation(lhs, rhs)
+    return date_compare_operation(lhs, rhs, "<=")
 
 
 @var_operation
@@ -142,26 +198,26 @@ def date_ge_operation(lhs: DateTimeVar | Any, rhs: DateTimeVar | Any):
     Returns:
         The result of the operation.
     """
-    return date_compare_operation(rhs, lhs)
+    return date_compare_operation(lhs, rhs, ">=")
 
 
 def date_compare_operation(
     lhs: DateTimeVar[DATETIME_T] | Any,
     rhs: DateTimeVar[DATETIME_T] | Any,
-    strict: bool = False,
+    operator: str,
 ) -> CustomVarOperationReturn[bool]:
-    """Check if the value is less than the other value.
+    """Compare datetime values by their timestamps.
 
     Args:
         lhs: The left-hand side of the operation.
         rhs: The right-hand side of the operation.
-        strict: Whether to use strict comparison.
+        operator: The comparison operator.
 
     Returns:
         The result of the operation.
     """
     return var_operation_return(
-        f"({lhs} {'<' if strict else '<='} {rhs})",
+        f"(new Date({lhs}).getTime() {operator} new Date({rhs}).getTime())",
         bool,
     )
 

tests/integration/tests_playwright/test_datetime_operations.py

@@ -7,14 +7,17 @@
 
 
 def DatetimeOperationsApp():
-    from datetime import datetime
+    from datetime import datetime, timedelta, timezone
 
     import reflex as rx
 
     class DtOperationsState(rx.State):
         date1: datetime = datetime(2021, 1, 1)
         date2: datetime = datetime(2031, 1, 1)
         date3: datetime = datetime(2021, 1, 1)
+        date4: datetime = datetime(2021, 1, 1, tzinfo=timezone.utc)
+        date5: datetime = datetime(2021, 1, 1, 1, tzinfo=timezone(timedelta(hours=1)))
+        date6: datetime = datetime(2021, 1, 1, 1, tzinfo=timezone(timedelta(hours=2)))
 
     app = rx.App(_state=DtOperationsState)
 
@@ -38,6 +41,13 @@ def index():
             rx.text(DtOperationsState.date1 <= DtOperationsState.date3, id="1_le_3"),
             rx.text(DtOperationsState.date1 > DtOperationsState.date3, id="1_gt_3"),
             rx.text(DtOperationsState.date1 >= DtOperationsState.date3, id="1_ge_3"),
+            rx.text("Operations with timezone offsets"),
+            rx.text(DtOperationsState.date4 == DtOperationsState.date5, id="4_eq_5"),
+            rx.text(DtOperationsState.date4 != DtOperationsState.date5, id="4_neq_5"),
+            rx.text(DtOperationsState.date6 < DtOperationsState.date4, id="6_lt_4"),
+            rx.text(DtOperationsState.date4 <= DtOperationsState.date5, id="4_le_5"),
+            rx.text(DtOperationsState.date4 > DtOperationsState.date6, id="4_gt_6"),
+            rx.text(DtOperationsState.date4 >= DtOperationsState.date5, id="4_ge_5"),
         )
 
 
@@ -85,3 +95,11 @@ def test_datetime_operations(datetime_operations_app: AppHarness, page: Page):
     expect(page.locator("id=1_le_3")).to_have_text("true")
     expect(page.locator("id=1_gt_3")).to_have_text("false")
     expect(page.locator("id=1_ge_3")).to_have_text("true")
+
+    # Check comparisons normalize timezone offsets
+    expect(page.locator("id=4_eq_5")).to_have_text("true")
+    expect(page.locator("id=4_neq_5")).to_have_text("false")
+    expect(page.locator("id=6_lt_4")).to_have_text("true")
+    expect(page.locator("id=4_le_5")).to_have_text("true")
+    expect(page.locator("id=4_gt_6")).to_have_text("true")
+    expect(page.locator("id=4_ge_5")).to_have_text("true")

tests/units/test_var.py

@@ -1,9 +1,11 @@
 import decimal
 import json
 import math
+import operator as op
 import re
 import typing
 from collections.abc import Mapping, Sequence
+from datetime import datetime, timedelta, timezone
 from typing import cast
 
 import pytest
@@ -366,6 +368,7 @@ def test_basic_operations(TestObj):
         str(LiteralArrayVar.create(["1", "2", "3"]).reverse())
         == '["1", "2", "3"].slice().reverse()'
     )
+
     assert (
         str(Var(_js_expr="foo")._var_set_state("state").to(list).reverse())
         == "state.foo.slice().reverse()"
@@ -374,6 +377,37 @@ def test_basic_operations(TestObj):
     assert str(Var(_js_expr="foo", _var_type=str).js_type()) == "(typeof(foo))"
 
 
+@pytest.mark.parametrize(
+    ("operation", "operator"),
+    [
+        (op.eq, "==="),
+        (op.ne, "!=="),
+        (op.lt, "<"),
+        (op.le, "<="),
+        (op.gt, ">"),
+        (op.ge, ">="),
+    ],
+)
+def test_datetime_comparison_uses_timestamps(operation, operator):
+    lhs = v(datetime(2024, 1, 1, 1, tzinfo=timezone(timedelta(hours=1))))
+    rhs = datetime(2024, 1, 1, tzinfo=timezone.utc)
+
+    assert str(operation(lhs, rhs)) == (
+        f'(new Date("2024-01-01 01:00:00+01:00").getTime() {operator} '
+        'new Date("2024-01-01 00:00:00+00:00").getTime())'
+    )
+
+
+def test_datetime_equality_with_other_type_uses_default_comparison():
+    value = v(datetime(2024, 1, 1))
+    expected_equality = (
+        '("2024-01-01 00:00:00"?.valueOf?.() === "2024-01-01 00:00:00"?.valueOf?.())'
+    )
+
+    assert str(value == "2024-01-01 00:00:00") == expected_equality
+    assert str(value != "2024-01-01 00:00:00") == f"!({expected_equality})"
+
+
 @pytest.mark.parametrize(
     ("var", "expected"),
     [