Fix now() behavior for DST (#483)

* Fix now() behavior for DST

* Upgrade pip before installing dependencies

Author: sdispater

.github/workflows/tests.yml

@@ -44,6 +44,10 @@ jobs:
       with:
         path: .venv
         key: venv-${{ runner.os }}-${{ steps.full-python-version.outputs.version }}-${{ hashFiles('**/poetry.lock') }}
+    - name: Upgrade pip
+      run: |
+        source $HOME/.poetry/env
+        poetry run python -m pip install pip -U
     - name: Install dependencies
       run: |
         source $HOME/.poetry/env
@@ -86,6 +90,10 @@ jobs:
       with:
         path: .venv
         key: venv-${{ runner.os }}-${{ steps.full-python-version.outputs.version }}-fix-${{ hashFiles('**/poetry.lock') }}
+    - name: Upgrade pip
+      run: |
+        source $HOME/.poetry/env
+        poetry run python -m pip install pip -U
     - name: Install dependencies
       run: |
         source $HOME/.poetry/env
@@ -127,6 +135,10 @@ jobs:
       with:
         path: .venv
         key: venv-${{ runner.os }}-${{ steps.full-python-version.outputs.version }}-${{ hashFiles('**/poetry.lock') }}
+    - name: Upgrade pip
+      run: |
+        $env:Path += ";$env:Userprofile\.poetry\bin"
+        poetry run python -m pip install pip -U
     - name: Install dependencies
       run: |
         $env:Path += ";$env:Userprofile\.poetry\bin"

pendulum/__init__.py

@@ -216,7 +216,17 @@ def now(tz=None):  # type: (Optional[Union[str, _Timezone]]) -> DateTime
         tz = _safe_timezone(tz)
         dt = tz.convert(dt)
 
-    return instance(dt, tz)
+    return DateTime(
+        dt.year,
+        dt.month,
+        dt.day,
+        dt.hour,
+        dt.minute,
+        dt.second,
+        dt.microsecond,
+        tzinfo=dt.tzinfo,
+        fold=dt.fold if _HAS_FOLD else 0,
+    )
 
 
 def today(tz="local"):  # type: (Union[str, _Timezone]) -> DateTime

poetry.lock

@@ -32,7 +32,7 @@ pytest = "^4.6"
 pytest-cov = "^2.5"
 pytz = ">=2018.3"
 babel = "^2.5"
-cleo = "^0.7.5"
+cleo = "^0.8.1"
 tox = "^3.0"
 black = { version = "^19.3b0", markers = "python_version >= '3.6' and python_version < '4.0' and implementation_name != 'pypy'" }
 isort = { version = "^4.3.21", markers = "python_version >= '3.6' and python_version < '4.0'" }
@@ -41,6 +41,7 @@ mkdocs = { version = "^1.0", python = "^3.5" }
 pymdown-extensions = "^6.0"
 pygments = "^2.2"
 markdown-include = "^0.5.1"
+freezegun = "^0.3.15"
 
 
 [tool.isort]
@@ -62,6 +63,7 @@ known_third_party = [
     "babel",
     "cleo",
     "dateutil",
+    "freezegun",
     "pytzdata",
 ]
 

pyproject.toml

@@ -3,13 +3,15 @@
 from datetime import datetime
 
 from dateutil import tz
+from freezegun import freeze_time
 
 import pendulum
 import pytest
 import pytz
 
 from pendulum import DateTime
 from pendulum.tz import timezone
+from pendulum.utils._compat import PY36
 
 from ..conftest import assert_datetime
 
@@ -102,6 +104,50 @@ def test_now():
     assert now.hour != in_paris.hour
 
 
+@pytest.mark.skipif(not PY36, reason="fold attribute only present in Python 3.6+")
+@freeze_time("2016-03-27 00:30:00")
+def test_now_dst_off():
+    utc = pendulum.now("UTC")
+    in_paris = pendulum.now("Europe/Paris")
+    in_paris_from_utc = utc.in_tz("Europe/Paris")
+    assert in_paris.hour == 1
+    assert not in_paris.is_dst()
+    assert in_paris.isoformat() == in_paris_from_utc.isoformat()
+
+
+@pytest.mark.skipif(not PY36, reason="fold attribute only present in Python 3.6+")
+@freeze_time("2016-03-27 01:30:00")
+def test_now_dst_transitioning_on():
+    utc = pendulum.now("UTC")
+    in_paris = pendulum.now("Europe/Paris")
+    in_paris_from_utc = utc.in_tz("Europe/Paris")
+    assert in_paris.hour == 3
+    assert in_paris.is_dst()
+    assert in_paris.isoformat() == in_paris_from_utc.isoformat()
+
+
+@pytest.mark.skipif(not PY36, reason="fold attribute only present in Python 3.6+")
+@freeze_time("2016-10-30 00:30:00")
+def test_now_dst_on():
+    utc = pendulum.now("UTC")
+    in_paris = pendulum.now("Europe/Paris")
+    in_paris_from_utc = utc.in_tz("Europe/Paris")
+    assert in_paris.hour == 2
+    assert in_paris.is_dst()
+    assert in_paris.isoformat() == in_paris_from_utc.isoformat()
+
+
+@pytest.mark.skipif(not PY36, reason="fold attribute only present in Python 3.6+")
+@freeze_time("2016-10-30 01:30:00")
+def test_now_dst_transitioning_off():
+    utc = pendulum.now("UTC")
+    in_paris = pendulum.now("Europe/Paris")
+    in_paris_from_utc = utc.in_tz("Europe/Paris")
+    assert in_paris.hour == 2
+    assert not in_paris.is_dst()
+    assert in_paris.isoformat() == in_paris_from_utc.isoformat()
+
+
 def test_now_with_fixed_offset():
     now = pendulum.now(6)