Merge pull request #369 from jmehnle/feature/time.monotonic

Add support for `time.monotonic` (and `time.monotonic_ns`)

AUTHORS.rst

@@ -16,3 +16,4 @@ Patches and Suggestions
 - `James Lu <github.com/CrazyPython>`_
 - `Dan Elkis <github.com/rinslow>`_
 - `Bastien Vallet <github.com/djailla>`_
+- `Julian Mehnle <github.com/jmehnle>`_

README.rst

@@ -13,7 +13,7 @@ FreezeGun is a library that allows your Python tests to travel through time by m
 Usage
 -----
 
-Once the decorator or context manager have been invoked, all calls to datetime.datetime.now(), datetime.datetime.utcnow(), datetime.date.today(), time.time(), time.localtime(), time.gmtime(), and time.strftime() will return the time that has been frozen.
+Once the decorator or context manager have been invoked, all calls to datetime.datetime.now(), datetime.datetime.utcnow(), datetime.date.today(), time.time(), time.localtime(), time.gmtime(), and time.strftime() will return the time that has been frozen. time.monotonic() will also be frozen, but as usual it makes no guarantees about its absolute value, only its changes over time.
 
 Decorator
 ~~~~~~~~~
@@ -174,7 +174,7 @@ FreezeGun allows for the time to be manually forwarded as well.
 
 .. code-block:: python
 
-    def test_manual_increment():
+    def test_manual_tick():
         initial_datetime = datetime.datetime(year=1, month=7, day=12,
                                             hour=15, minute=6, second=3)
         with freeze_time(initial_datetime) as frozen_datetime:
@@ -188,6 +188,18 @@ FreezeGun allows for the time to be manually forwarded as well.
             initial_datetime += datetime.timedelta(seconds=10)
             assert frozen_datetime() == initial_datetime
 
+.. code-block:: python
+
+    def test_monotonic_manual_tick():
+        initial_datetime = datetime.datetime(year=1, month=7, day=12,
+                                            hour=15, minute=6, second=3)
+        with freeze_time(initial_datetime) as frozen_datetime:
+            monotonic_t0 = time.monotonic()
+            frozen_datetime.tick(1.0)
+            monotonic_t1 = time.monotonic()
+            assert monotonic_t1 == monotonic_t0 + 1.0
+
+
 Moving time to specify datetime
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

freezegun/api.py

@@ -22,21 +22,27 @@
     MayaDT = None
 
 _TIME_NS_PRESENT = hasattr(time, 'time_ns')
+_MONOTONIC_NS_PRESENT = hasattr(time, 'monotonic_ns')
 _EPOCH = datetime.datetime(1970, 1, 1)
 _EPOCHTZ = datetime.datetime(1970, 1, 1, tzinfo=dateutil.tz.UTC)
 
 real_time = time.time
 real_localtime = time.localtime
 real_gmtime = time.gmtime
+real_monotonic = time.monotonic
 real_strftime = time.strftime
 real_date = datetime.date
 real_datetime = datetime.datetime
-real_date_objects = [real_time, real_localtime, real_gmtime, real_strftime, real_date, real_datetime]
+real_date_objects = [real_time, real_localtime, real_gmtime, real_monotonic, real_strftime, real_date, real_datetime]
 
 if _TIME_NS_PRESENT:
     real_time_ns = time.time_ns
     real_date_objects.append(real_time_ns)
 
+if _MONOTONIC_NS_PRESENT:
+    real_monotonic_ns = time.monotonic_ns
+    real_date_objects.append(real_monotonic_ns)
+
 _real_time_object_ids = {id(obj) for obj in real_date_objects}
 
 # time.clock is deprecated and was removed in Python 3.8
@@ -211,6 +217,23 @@ def fake_gmtime(t=None):
     return get_current_time().timetuple()
 
 
+def fake_monotonic():
+    if _should_use_real_time():
+        return real_monotonic()
+    current_time = get_current_time()
+    return calendar.timegm(current_time.timetuple()) + current_time.microsecond / 1000000.0
+
+if _MONOTONIC_NS_PRESENT:
+    def fake_monotonic_ns():
+        if _should_use_real_time():
+            return real_monotonic_ns()
+        current_time = get_current_time()
+        return (
+            calendar.timegm(current_time.timetuple()) * 1000000 +
+            current_time.microsecond
+        ) * 1000
+
+
 def fake_strftime(format, time_to_format=None):
     if time_to_format is None:
         if not _should_use_real_time():
@@ -609,6 +632,7 @@ def start(self):
         datetime.date = FakeDate
 
         time.time = fake_time
+        time.monotonic = fake_monotonic
         time.localtime = fake_localtime
         time.gmtime = fake_gmtime
         time.strftime = fake_strftime
@@ -626,6 +650,7 @@ def start(self):
             ('real_datetime', real_datetime, FakeDatetime),
             ('real_gmtime', real_gmtime, fake_gmtime),
             ('real_localtime', real_localtime, fake_localtime),
+            ('real_monotonic', real_monotonic, fake_monotonic),
             ('real_strftime', real_strftime, fake_strftime),
             ('real_time', real_time, fake_time),
         ]
@@ -634,6 +659,10 @@ def start(self):
             time.time_ns = fake_time_ns
             to_patch.append(('real_time_ns', real_time_ns, fake_time_ns))
 
+        if _MONOTONIC_NS_PRESENT:
+            time.monotonic_ns = fake_monotonic_ns
+            to_patch.append(('real_monotonic_ns', real_monotonic_ns, fake_monotonic_ns))
+
         if real_clock is not None:
             # time.clock is deprecated and was removed in Python 3.8
             time.clock = fake_clock
@@ -710,6 +739,7 @@ def stop(self):
                             setattr(module, module_attribute, real)
 
             time.time = real_time
+            time.monotonic = real_monotonic
             time.gmtime = real_gmtime
             time.localtime = real_localtime
             time.strftime = real_strftime
@@ -718,6 +748,9 @@ def stop(self):
             if _TIME_NS_PRESENT:
                 time.time_ns = real_time_ns
 
+            if _MONOTONIC_NS_PRESENT:
+                time.monotonic_ns = real_monotonic_ns
+
             if uuid_generate_time_attr:
                 setattr(uuid, uuid_generate_time_attr, real_uuid_generate_time)
             uuid._UuidCreate = real_uuid_create

tests/test_datetimes.py

@@ -21,6 +21,7 @@
 # time.clock was removed in Python 3.8
 HAS_CLOCK = hasattr(time, 'clock')
 HAS_TIME_NS = hasattr(time, 'time_ns')
+HAS_MONOTONIC_NS = hasattr(time, 'monotonic_ns')
 
 class temp_locale(object):
     """Temporarily change the locale."""
@@ -57,12 +58,14 @@ def test_simple_api():
 
     freezer.start()
     assert time.time() == expected_timestamp
+    assert time.monotonic() >= 0.0
     assert datetime.datetime.now() == datetime.datetime(2012, 1, 14)
     assert datetime.datetime.utcnow() == datetime.datetime(2012, 1, 14)
     assert datetime.date.today() == datetime.date(2012, 1, 14)
     assert datetime.datetime.now().today() == datetime.datetime(2012, 1, 14)
     freezer.stop()
     assert time.time() != expected_timestamp
+    assert time.monotonic() >= 0.0
     assert datetime.datetime.now() != datetime.datetime(2012, 1, 14)
     assert datetime.datetime.utcnow() != datetime.datetime(2012, 1, 14)
     freezer = freeze_time("2012-01-10 13:52:01")
@@ -113,6 +116,7 @@ def test_zero_tz_offset_with_time():
     assert datetime.datetime.now() == datetime.datetime(1970, 1, 1)
     assert datetime.datetime.utcnow() == datetime.datetime(1970, 1, 1)
     assert time.time() == 0.0
+    assert time.monotonic() >= 0.0
     freezer.stop()
 
 
@@ -125,6 +129,7 @@ def test_tz_offset_with_time():
     assert datetime.datetime.now() == datetime.datetime(1969, 12, 31, 20)
     assert datetime.datetime.utcnow() == datetime.datetime(1970, 1, 1)
     assert time.time() == 0.0
+    assert time.monotonic() >= 0
     freezer.stop()
 
 
@@ -197,6 +202,29 @@ def test_bad_time_argument():
         assert False, "Bad values should raise a ValueError"
 
 
+def test_time_monotonic():
+    initial_datetime = datetime.datetime(year=1, month=7, day=12,
+                                        hour=15, minute=6, second=3)
+    with freeze_time(initial_datetime) as frozen_datetime:
+        monotonic_t0 = time.monotonic()
+        if HAS_MONOTONIC_NS:
+            monotonic_ns_t0 = time.monotonic_ns()
+
+        frozen_datetime.tick()
+        monotonic_t1 = time.monotonic()
+        assert monotonic_t1 == monotonic_t0 + 1.0
+        if HAS_MONOTONIC_NS:
+            monotonic_ns_t1 = time.monotonic_ns()
+            assert monotonic_ns_t1 == monotonic_ns_t0 + 1000000000
+
+        frozen_datetime.tick(10)
+        monotonic_t11 = time.monotonic()
+        assert monotonic_t11 == monotonic_t1 + 10.0
+        if HAS_MONOTONIC_NS:
+            monotonic_ns_t11 = time.monotonic_ns()
+            assert monotonic_ns_t11 == monotonic_ns_t1 + 10000000000
+
+
 def test_time_gmtime():
     with freeze_time('2012-01-14 03:21:34'):
         time_struct = time.gmtime()
@@ -649,6 +677,20 @@ def test_time_with_nested():
         assert time() == second
 
 
+def test_monotonic_with_nested():
+    from time import monotonic
+
+    with freeze_time('2015-01-01') as frozen_datetime_1:
+        initial_monotonic_1 = time.monotonic()
+        with freeze_time('2015-12-25') as frozen_datetime_2:
+            initial_monotonic_2 = time.monotonic()
+            frozen_datetime_2.tick()
+            assert time.monotonic() == initial_monotonic_2 + 1
+        assert time.monotonic() == initial_monotonic_1
+        frozen_datetime_1.tick()
+        assert time.monotonic() == initial_monotonic_1 + 1
+
+
 def test_should_use_real_time():
     frozen = datetime.datetime(2015, 3, 5)
     expected_frozen = 1425513600.0

tests/test_ticking.py

@@ -62,6 +62,14 @@ def test_ticking_time():
         assert time.time() > 1326585599.0
 
 
+@utils.cpython_only
+def test_ticking_monotonic():
+    with freeze_time("Jan 14th, 2012, 23:59:59", tick=True):
+        initial_monotonic = time.monotonic()
+        time.sleep(0.001)  # Deal with potential clock resolution problems
+        assert time.monotonic() > initial_monotonic
+
+
 @mock.patch('freezegun.api._is_cpython', False)
 def test_pypy_compat():
     try: