Use subprocess42 in recipe_engine to avoid threading madness.

recipe_engine/unittests/step_runner_test.py

+#!/usr/bin/env python
+# Copyright 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+import shutil
+import sys
+import tempfile
+import unittest
+
+sys.path.append(os.path.dirname(os.path.dirname(os.path.dirname(
+    os.path.abspath(__file__)))))
+
+from recipe_engine import step_runner
+
+
+class TestLinebuf(unittest.TestCase):
+  def test_add_partial(self):
+    lb = step_runner._streamingLinebuf()
+    lb.ingest("blarf")
+    self.assertEqual([], list(lb))
+
+  def test_add_whole(self):
+    lb = step_runner._streamingLinebuf()
+    lb.ingest("blarf\n")
+    self.assertEqual(["blarf"], list(lb))
+
+  def test_add_partial_whole(self):
+    lb = step_runner._streamingLinebuf()
+    lb.ingest("foof\nfleem\nblarf")
+    self.assertEqual(["foof", "fleem"], list(lb))
+
+  def test_leftovers(self):
+    lb = step_runner._streamingLinebuf()
+
+    lb.ingest("nerds")
+    self.assertEqual([], list(lb))
+
+    lb.ingest("doop\n")
+    self.assertEqual(["nerdsdoop"], list(lb))
+
+    self.assertEqual([], list(lb))
+
+
+if __name__ == '__main__':
+  unittest.main()