Feat: Add duration format hook (pytest-dev#724)

docs/user_guide.rst

@@ -304,6 +304,28 @@ Note that the values are case *sensitive*.
 If tests are run in parallel (with `pytest-xdist`_ for example), then the order may not be
 in the correct order.
 
+Formatting the Duration Column
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The formatting of the timestamp used in the :code:`Durations` column can be modified by using the
+:code:`pytest_html_duration_format` hook. The default timestamp will be `nnn ms` for durations
+less than one second and `hh:mm:ss` for durations equal to or greater than one second.
+
+Below is an example of a :code:`conftest.py` file setting :code:`pytest_html_duration_format`:
+
+.. code-block:: python
+
+  import datetime
+
+
+  def pytest_html_duration_format(duration):
+      duration_timedelta = datetime.timedelta(seconds=duration)
+      time = datetime.datetime(1, 1, 1) + duration_timedelta
+      return time.strftime("%H:%M:%S")
+
+**NOTE**: The behavior of sorting the duration column is not guaranteed when providing a custom format.
+
+**NOTE**: The formatting of the total duration is not affected by this hook.
 
 .. _@pytest.hookimpl(tryfirst=True): https://docs.pytest.org/en/stable/writing_plugins.html#hook-function-ordering-call-example
 .. _ansi2html: https://pypi.python.org/pypi/ansi2html/

src/pytest_html/basereport.py

@@ -197,12 +197,19 @@ def pytest_collection_finish(self, session):
     def pytest_runtest_logreport(self, report):
         if hasattr(report, "duration_formatter"):
             warnings.warn(
-                "'duration_formatter' has been removed and no longer has any effect!",
+                "'duration_formatter' has been removed and no longer has any effect!"
+                "Please use the 'pytest_html_duration_format' hook instead.",
                 DeprecationWarning,
             )
 
         outcome = _process_outcome(report)
-        duration = _format_duration(report.duration)
+        try:
+            # hook returns as list for some reason
+            duration = self._config.hook.pytest_html_duration_format(
+                duration=report.duration
+            )[0]
+        except IndexError:
+            duration = _format_duration(report.duration)
         self._report.total_duration += report.duration
 
         test_id = report.nodeid

src/pytest_html/hooks.py

@@ -21,3 +21,7 @@ def pytest_html_results_table_row(report, cells):
 
 def pytest_html_results_table_html(report, data):
     """Called after building results table additional HTML."""
+
+
+def pytest_html_duration_format(duration):
+    """Called before using the default duration formatting."""

testing/test_integration.py

@@ -156,6 +156,21 @@ def test_sleep():
             assert_that(duration).matches(expectation)
             assert_that(total_duration).matches(r"\d{2}:\d{2}:\d{2}")
 
+    def test_duration_format_hook(self, pytester):
+        pytester.makeconftest(
+            """
+            def pytest_html_duration_format(duration):
+                return str(round(duration * 1000)) + " seconds"
+            """
+        )
+
+        pytester.makepyfile("def test_pass(): pass")
+        page = run(pytester)
+        assert_results(page, passed=1)
+
+        duration = get_text(page, "#results-table td[class='col-duration']")
+        assert_that(duration).contains("seconds")
+
     def test_total_number_of_tests_zero(self, pytester):
         page = run(pytester)
         assert_results(page)