Add time zone to start and end time in metadata

Prior to this we were including a naive datetime, which did not include
enough information to allow it to be localized if a report was viewed on
a machine with a different time zone than the one it was generated on.

Signed-off-by: Matt Wozniski <[email protected]>

news/611.bugfix.rst

@@ -0,0 +1 @@
+Correctly localize the start and end time in the "Stats" modal when an HTML report was generated on a different machine than the one it is being displayed on.

src/memray/_memray.pyx

@@ -735,7 +735,7 @@ def print_greenlet_warning():
 
 cdef millis_to_dt(millis):
     return datetime.fromtimestamp(millis // 1000).replace(
-        microsecond=millis % 1000 * 1000)
+        microsecond=millis % 1000 * 1000).astimezone()
 
 
 cdef _create_metadata(header, peak_memory):

tests/integration/test_tracking.py

@@ -1539,11 +1539,11 @@ def test_get_header(self, monkeypatch, tmpdir):
 
         monkeypatch.setattr(sys, "argv", ["python", "-m", "pytest"])
         with run_without_tracer():
-            start_time = datetime.datetime.now()
+            start_time = datetime.datetime.now().astimezone()
             with Tracker(output):
                 for _ in range(100):
                     allocator.valloc(1024)
-            end_time = datetime.datetime.now()
+            end_time = datetime.datetime.now().astimezone()
 
         reader = FileReader(output)
         n_records = len(list(reader.get_allocation_records()))
@@ -1570,11 +1570,11 @@ def test_get_header_after_snapshot(self, monkeypatch, tmpdir):
         # WHEN
 
         monkeypatch.setattr(sys, "argv", ["python", "-m", "pytest"])
-        start_time = datetime.datetime.now()
+        start_time = datetime.datetime.now().astimezone()
         with Tracker(output):
             for _ in range(100):
                 allocator.valloc(1024)
-        end_time = datetime.datetime.now()
+        end_time = datetime.datetime.now().astimezone()
 
         reader = FileReader(output)
         peak, *_ = list(reader.get_high_watermark_allocation_records())