Fetch contents of DerivedData after each test

ios/build/bots/scripts/test_runner.py

Index: ios/build/bots/scripts/test_runner.py
diff --git a/ios/build/bots/scripts/test_runner.py b/ios/build/bots/scripts/test_runner.py
index b06cbbbec003d78f2719b11d3a31af3358754df0..6cc4fc4eef4292b7b8f3686404c55cedec4d3327 100644
--- a/ios/build/bots/scripts/test_runner.py
+++ b/ios/build/bots/scripts/test_runner.py
@@ -19,6 +19,9 @@ import gtest_utils
 import xctest_utils
 
 
+DERIVED_DATA = os.path.expanduser('~/Library/Developer/Xcode/DerivedData')
+
+
 XCTEST_PROJECT = os.path.abspath(os.path.join(
   os.path.dirname(__file__),
   'TestProject',
@@ -230,6 +233,26 @@ class TestRunner(object):
         os.path.join(self.out_dir, 'desktop_%s.png' % time.time()),
     ])
 
+  def retrieve_derived_data(self):
+    """Retrieves the contents of DerivedData"""
+    # DerivedData contains some logs inside workspace-specific directories.
+    # Since we don't control the name of the workspace or project, most of
+    # the directories are just called "temporary", making it hard to tell
+    # which directory we need to retrieve. Instead we just delete the
+    # entire contents of this directory before starting and return the
+    # entire contents after the test is over.
+    if os.path.exists(DERIVED_DATA):
+      os.mkdir(os.path.join(self.out_dir, 'DerivedData'))
+      derived_data = os.path.join(self.out_dir, 'DerivedData')
+      for directory in os.listdir(DERIVED_DATA):
+        shutil.move(os.path.join(DERIVED_DATA, directory), derived_data)
+
+  def wipe_derived_data(self):
+    """Removes the contents of Xcode's DerivedData directory."""
+    if os.path.exists(DERIVED_DATA):
+      shutil.rmtree(DERIVED_DATA)
+      os.mkdir(DERIVED_DATA)
+
   def _run(self, cmd):
     """Runs the specified command, parsing GTest output.
 
@@ -436,6 +459,7 @@ class SimulatorTestRunner(TestRunner):
     """Performs setup actions which must occur prior to every test launch."""
     self.kill_simulators()
     self.wipe_simulator()
+    self.wipe_derived_data()
     self.homedir = self.get_home_directory()
     # Crash reports have a timestamp in their file name, formatted as
     # YYYY-MM-DD-HHMMSS. Save the current time in the same format so
@@ -493,6 +517,7 @@ class SimulatorTestRunner(TestRunner):
     """Performs cleanup actions which must occur after every test launch."""
     self.extract_test_data()
     self.retrieve_crash_reports()
+    self.retrieve_derived_data()
     self.screenshot_desktop()
     self.kill_simulators()
     self.wipe_simulator()
@@ -603,6 +628,7 @@ class DeviceTestRunner(TestRunner):
   def set_up(self):
     """Performs setup actions which must occur prior to every test launch."""
     self.uninstall_apps()
+    self.wipe_derived_data()
     self.install_app()
 
   def extract_test_data(self):
@@ -635,6 +661,7 @@ class DeviceTestRunner(TestRunner):
   def tear_down(self):
     """Performs cleanup actions which must occur after every test launch."""
     self.screenshot_desktop()
+    self.retrieve_derived_data()
     self.extract_test_data()
     self.retrieve_crash_reports()
     self.uninstall_apps()