Fixes issue #11314 - log_file_format does not default to log_format (#11444)

* Fixes issue #11314 -

* Incorporated review comments for issue #11314

* Update changelog/11314.improvement.rst

Co-authored-by: Bruno Oliveira <bruno@soliv.dev>

---------

Co-authored-by: Zac Hatfield-Dodds <zac.hatfield.dodds@gmail.com>
Co-authored-by: Bruno Oliveira <bruno@soliv.dev>

AUTHORS

@@ -345,6 +345,7 @@ Segev Finer
 Serhii Mozghovyi
 Seth Junot
 Shantanu Jain
+Sharad Nair
 Shubham Adep
 Simon Gomizelj
 Simon Holesch

changelog/11314.improvement.rst

@@ -0,0 +1,2 @@
+Logging to a file using the ``--log-file`` option will use ``--log-level``, ``--log-format`` and ``--log-date-format`` as fallback
+if ``--log-file-level``, ``--log-file-format`` and ``--log-file-date-format`` are not provided respectively.

src/_pytest/logging.py

@@ -303,13 +303,13 @@ def pytest_addoption(parser: Parser) -> None:
     add_option_ini(
         "--log-file-format",
         dest="log_file_format",
-        default=DEFAULT_LOG_FORMAT,
+        default=None,
         help="Log format used by the logging module",
     )
     add_option_ini(
         "--log-file-date-format",
         dest="log_file_date_format",
-        default=DEFAULT_LOG_DATE_FORMAT,
+        default=None,
         help="Log date format used by the logging module",
     )
     add_option_ini(
@@ -635,7 +635,9 @@ class LoggingPlugin:
         self.report_handler.setFormatter(self.formatter)
 
         # File logging.
-        self.log_file_level = get_log_level_for_setting(config, "log_file_level")
+        self.log_file_level = get_log_level_for_setting(
+            config, "log_file_level", "log_level"
+        )
         log_file = get_option_ini(config, "log_file") or os.devnull
         if log_file != os.devnull:
             directory = os.path.dirname(os.path.abspath(log_file))

testing/logging/test_reporting.py

@@ -77,14 +77,14 @@ def test_root_logger_affected(pytester: Pytester) -> None:
     assert "warning text going to logger" not in stdout
     assert "info text going to logger" not in stdout
 
-    # The log file should contain the warning and the error log messages and
+    # The log file should only contain the error log messages and
-    # not the info one, because the default level of the root logger is
+    # not the warning or info ones, because the root logger is set to
-    # WARNING.
+    # ERROR using --log-level=ERROR.
     assert os.path.isfile(log_file)
     with open(log_file, encoding="utf-8") as rfh:
         contents = rfh.read()
         assert "info text going to logger" not in contents
-        assert "warning text going to logger" in contents
+        assert "warning text going to logger" not in contents
         assert "error text going to logger" in contents
 
 
@@ -1331,3 +1331,62 @@ def test_date_format_percentf_tz_log(pytester: Pytester) -> None:
     result.stdout.re_match_lines(
         [r"^[0-9-]{10} [0-9:]{8}.[0-9]{6}[+-][0-9\.]+; WARNING; text"]
     )
+
+
+def test_log_file_cli_fallback_options(pytester: Pytester) -> None:
+    """Make sure that fallback values for log-file formats and level works."""
+    pytester.makepyfile(
+        """
+        import logging
+        logger = logging.getLogger()
+
+        def test_foo():
+            logger.info('info text going to logger')
+            logger.warning('warning text going to logger')
+            logger.error('error text going to logger')
+
+            assert 0
+    """
+    )
+    log_file = str(pytester.path.joinpath("pytest.log"))
+    result = pytester.runpytest(
+        "--log-level=ERROR",
+        "--log-format=%(asctime)s %(message)s",
+        "--log-date-format=%H:%M",
+        "--log-file=pytest.log",
+    )
+    assert result.ret == 1
+
+    # The log file should only contain the error log messages
+    # not the warning or info ones and the format and date format
+    # should match the formats provided using --log-format and --log-date-format
+    assert os.path.isfile(log_file)
+    with open(log_file, encoding="utf-8") as rfh:
+        contents = rfh.read()
+        assert re.match(r"[0-9]{2}:[0-9]{2} error text going to logger\s*", contents)
+        assert "info text going to logger" not in contents
+        assert "warning text going to logger" not in contents
+        assert "error text going to logger" in contents
+
+    # Try with a different format and date format to make sure that the formats
+    # are being used
+    result = pytester.runpytest(
+        "--log-level=ERROR",
+        "--log-format=%(asctime)s : %(message)s",
+        "--log-date-format=%H:%M:%S",
+        "--log-file=pytest.log",
+    )
+    assert result.ret == 1
+
+    # The log file should only contain the error log messages
+    # not the warning or info ones and the format and date format
+    # should match the formats provided using --log-format and --log-date-format
+    assert os.path.isfile(log_file)
+    with open(log_file, encoding="utf-8") as rfh:
+        contents = rfh.read()
+        assert re.match(
+            r"[0-9]{2}:[0-9]{2}:[0-9]{2} : error text going to logger\s*", contents
+        )
+        assert "info text going to logger" not in contents
+        assert "warning text going to logger" not in contents
+        assert "error text going to logger" in contents