Update timing data keys, not overwrite it entirely.

This will be necessary when we implement overridden atoms from build
requests. In such a build request, we will not have ran all the atoms,
and if we were to keep the existing behavior, we would wipe out all of
the atom timing data except for the select few that were manually
specified in the build request.

This method also leaves the door open in the future if we want to always
update the timing data, regardless of overall build success/failure, but
only for successful atoms.

app/master/build_artifact.py

@@ -47,9 +47,9 @@ def write_timing_data(self, timing_file_path, timing_data):
             self._logger.debug('Created new timing file in {}', timing_file_path)
             return
 
-        # If file exists, only overwrite timing data if there were no failures this build
+        # If file exists, only update timing data if there were no failures this build
         if len(self.get_failed_commands()) == 0:
-            self._write_timing_data_to_file(timing_file_path, timing_data)
+            self._update_timing_file(timing_file_path, timing_data)
             self._logger.debug('Overwrote existing timing file in {}', timing_file_path)
             return
 
@@ -104,12 +104,26 @@ def generate_failures_file(self):
             with open(os.path.join(self.build_artifact_dir, 'failures.txt'), 'w') as f:
                 f.write("\n".join(failed_atoms))
 
-    def _write_timing_data_to_file(self, path, timing_data):
+    def _write_timing_data_to_file(self, timing_file_path, timing_data):
         """
-        :type path: str
+        :type timing_file_path: str
         :type timing_data: dict[str, float]
         """
-        app.util.fs.write_file(json.dumps(timing_data), path)
+        app.util.fs.write_file(json.dumps(timing_data), timing_file_path)
+
+    def _update_timing_file(self, timing_file_path, new_timing_data):
+        """
+        Update the timing data for the atoms specified in new_timing_data. This means that new results
+        does not replace the entire timing data file, but rather only replaces the timing data for
+        individual atom keys.
+        :param timing_file_path: str
+        :param new_timing_data: dict[str, float]
+        """
+        with open(timing_file_path) as timing_file:
+            timing_data = json.load(timing_file)
+
+        timing_data.update(new_timing_data)
+        app.util.fs.write_file(json.dumps(timing_data), timing_file_path)
 
     @staticmethod
     def atom_artifact_directory(build_id, subjob_id, atom_id, result_root=None):

test/unit/master/test_atomizer.py

@@ -1,6 +1,7 @@
 from unittest.mock import Mock
-from app.master.atomizer import Atomizer, AtomizerError
 
+from app.master.atomizer import Atomizer, AtomizerError
+from app.project_type.project_type import ProjectType
 from app.util.process_utils import get_environment_variable_setter_command
 from test.framework.base_unit_test_case import BaseUnitTestCase
 
@@ -13,7 +14,7 @@
 
 class TestAtomizer(BaseUnitTestCase):
     def test_atomizer_returns_expected_atom_list(self):
-        mock_project = Mock()
+        mock_project = Mock(spec=ProjectType)
         mock_project.execute_command_in_project.return_value = (_FAKE_ATOMIZER_COMMAND_OUTPUT, _SUCCESSFUL_EXIT_CODE)
         mock_project.project_directory = '/tmp/test/directory'
 
@@ -31,7 +32,7 @@ def test_atomizer_returns_expected_atom_list(self):
         mock_project.execute_command_in_project.assert_called_once_with(_FAKE_ATOMIZER_COMMAND)
 
     def test_atomizer_raises_exception_when_atomize_command_fails(self):
-        mock_project = Mock()
+        mock_project = Mock(spec=ProjectType)
         mock_project.execute_command_in_project.return_value = ('ERROR ERROR ERROR', _FAILING_EXIT_CODE)
 
         atomizer = Atomizer([{'TEST_FILE': _FAKE_ATOMIZER_COMMAND}])