Live log option now writes to the terminal reporter

Ref: pytest-dev#3013

Author: nicoddemus

_pytest/logging.py

@@ -2,7 +2,6 @@
 
 import logging
 from contextlib import closing, contextmanager
-import sys
 import six
 
 import pytest
@@ -263,30 +262,13 @@ def __init__(self, config):
         The formatter can be safely shared across all handlers so
         create a single one for the entire test session here.
         """
+        self._config = config
         self.print_logs = get_option_ini(config, 'log_print')
         self.formatter = logging.Formatter(
             get_option_ini(config, 'log_format'),
             get_option_ini(config, 'log_date_format'))
         self.log_level = get_actual_log_level(config, 'log_level')
 
-        if config.getini('log_cli'):
-            log_cli_handler = logging.StreamHandler(sys.stderr)
-            log_cli_format = get_option_ini(
-                config, 'log_cli_format', 'log_format')
-            log_cli_date_format = get_option_ini(
-                config, 'log_cli_date_format', 'log_date_format')
-            log_cli_formatter = logging.Formatter(
-                log_cli_format,
-                datefmt=log_cli_date_format)
-            log_cli_level = get_actual_log_level(config, 'log_cli_level', 'log_level')
-            self.log_cli_handler = log_cli_handler  # needed for a single unittest
-            self.live_logs_context = catching_logs(log_cli_handler,
-                                                   formatter=log_cli_formatter,
-                                                   level=log_cli_level)
-        else:
-            self.log_cli_handler = None
-            self.live_logs_context = _dummy_context_manager()
-
         log_file = get_option_ini(config, 'log_file')
         if log_file:
             self.log_file_level = get_actual_log_level(config, 'log_file_level')
@@ -340,6 +322,7 @@ def pytest_runtest_teardown(self, item):
     @pytest.hookimpl(hookwrapper=True)
     def pytest_runtestloop(self, session):
         """Runs all collected test items."""
+        self._setup_cli_logging()
         with self.live_logs_context:
             if self.log_file_handler is not None:
                 with closing(self.log_file_handler):
@@ -348,3 +331,27 @@ def pytest_runtestloop(self, session):
                         yield  # run all the tests
             else:
                 yield  # run all the tests
+
+    def _setup_cli_logging(self):
+        """Setups the handler and logger for the Live Logs feature, if enabled.
+
+        This must be done right before starting the loop so we can access the terminal reporter plugin.
+        """
+        terminal_reporter = self._config.pluginmanager.get_plugin('terminalreporter')
+        if self._config.getini('log_cli') and terminal_reporter is not None:
+            log_cli_handler = logging.StreamHandler(terminal_reporter._tw)
+            log_cli_format = get_option_ini(
+                self._config, 'log_cli_format', 'log_format')
+            log_cli_date_format = get_option_ini(
+                self._config, 'log_cli_date_format', 'log_date_format')
+            log_cli_formatter = logging.Formatter(
+                log_cli_format,
+                datefmt=log_cli_date_format)
+            log_cli_level = get_actual_log_level(self._config, 'log_cli_level', 'log_level')
+            self.log_cli_handler = log_cli_handler  # needed for a single unittest
+            self.live_logs_context = catching_logs(log_cli_handler,
+                                                   formatter=log_cli_formatter,
+                                                   level=log_cli_level)
+        else:
+            self.log_cli_handler = None
+            self.live_logs_context = _dummy_context_manager()

testing/logging/test_reporting.py

@@ -156,9 +156,9 @@ def test_log_cli():
         ''')
     result = testdir.runpytest('-s')
     if enabled:
-        assert msg in result.stderr.str()
+        assert msg in result.stdout.str()
     else:
-        assert msg not in result.stderr.str()
+        assert msg not in result.stdout.str()
 
 
 def test_log_cli_default_level(testdir):
@@ -182,12 +182,13 @@ def test_log_cli(request):
 
     # fnmatch_lines does an assertion internally
     result.stdout.fnmatch_lines([
-        'test_log_cli_default_level.py PASSED',
+        'test_log_cli_default_level.py*',
+        'PASSED',  # 'PASSED' on its own line because the log message prints a new line
     ])
-    result.stderr.fnmatch_lines([
+    result.stdout.fnmatch_lines([
         '*WARNING message will be shown*',
     ])
-    assert "INFO message won't be shown" not in result.stderr.str()
+    assert "INFO message won't be shown" not in result.stdout.str()
     # make sure that that we get a '0' exit code for the testsuite
     assert result.ret == 0
 
@@ -213,12 +214,13 @@ def test_log_cli(request):
 
     # fnmatch_lines does an assertion internally
     result.stdout.fnmatch_lines([
-        'test_log_cli_level.py PASSED',
+        'test_log_cli_level.py*',
+        'PASSED',  # 'PASSED' on its own line because the log message prints a new line
     ])
-    result.stderr.fnmatch_lines([
+    result.stdout.fnmatch_lines([
         "* This log message will be shown"
     ])
-    for line in result.errlines:
+    for line in result.outlines:
         try:
             assert "This log message won't be shown" in line
             pytest.fail("A log message was shown and it shouldn't have been")
@@ -232,12 +234,13 @@ def test_log_cli(request):
 
     # fnmatch_lines does an assertion internally
     result.stdout.fnmatch_lines([
-        'test_log_cli_level.py PASSED',
+        'test_log_cli_level.py*',
+        'PASSED',  # 'PASSED' on its own line because the log message prints a new line
     ])
-    result.stderr.fnmatch_lines([
+    result.stdout.fnmatch_lines([
         "* This log message will be shown"
     ])
-    for line in result.errlines:
+    for line in result.outlines:
         try:
             assert "This log message won't be shown" in line
             pytest.fail("A log message was shown and it shouldn't have been")
@@ -270,12 +273,13 @@ def test_log_cli(request):
 
     # fnmatch_lines does an assertion internally
     result.stdout.fnmatch_lines([
-        'test_log_cli_ini_level.py PASSED',
+        'test_log_cli_ini_level.py*',
+        'PASSED',  # 'PASSED' on its own line because the log message prints a new line
     ])
-    result.stderr.fnmatch_lines([
+    result.stdout.fnmatch_lines([
         "* This log message will be shown"
     ])
-    for line in result.errlines:
+    for line in result.outlines:
         try:
             assert "This log message won't be shown" in line
             pytest.fail("A log message was shown and it shouldn't have been")