Hide console log messages for imported WPT tests

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/driver.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/driver.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/driver.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/driver.py
index c0cecf91e649efb7c4eaf6da535e08ca5702df7e..32dfb8d1324ba5a1196eecbe1b011a4b168e94d5 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/driver.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/driver.py
@@ -207,6 +207,12 @@ class Driver(object):
                 if self.error_from_test:
                     crash_log += '\nstdout:\n%s\nstderr:\n%s\n' % (text, self.error_from_test)
 
+        # filter console output for WPT tests into stderr so that tests not
+        # designed for it do not fail when console messages appear in a
+        # non-deterministic order.
+        if self.WPT_DIR in driver_input.test_name:
+            text, self.error_from_test = self._filter_console_output_into_stderr(text, self.error_from_test)
+
         return DriverOutput(text, image, actual_image_hash, audio,
                             crash=crashed, test_time=time.time() - test_begin_time, measurements=self._measurements,
                             timeout=timed_out, error=self.error_from_test,
@@ -215,6 +221,28 @@ class Driver(object):
                             leak=leaked, leak_log=self._leak_log,
                             pid=pid)
 
+    def _filter_console_output_into_stderr(self, out, stderr):
+        if out is None:
+            return None, stderr
+
+        new_out = ''
+        console_output = ''
+
+        for line in out.splitlines():
+            line += '\n'
+            if line.startswith('CONSOLE'):
+                console_output += line
+            else:
+                new_out += line

[qyearsley, 2017/02/16 18:54:43]

Console messages can have newlines in them -- so for example, if out is:

"""PASS: first test
CONSOLE WARNING: Line 1
Line 2
PASS: second test
"""

Then new_out would be:

"""PASS: first test
Line 2
PASS: second test
"""

But we don't want it to include "line 2".

Could you add a unit test to check this behavior?

[Dan Elphick, 2017/02/17 15:04:40]

Just checked and this changes fails for new lines. To fix this, I changed the
logger to repeat the CONSOLE prefix for each line of a message.

+
+        if console_output:
+            if stderr:
+                stderr += '\n'
+
+            stderr = stderr + 'Console Output:\n' + console_output
+
+        return new_out, stderr
+
     def _get_crash_log(self, stdout, stderr, newer_than):
         return self._port._get_crash_log(self._crashed_process_name, self._crashed_pid, stdout, stderr, newer_than)