Replace recipes_test.py with a new parallel expectation-based test runner.

scripts/slave/unittests/expect_tests/handle_train.py

Index: scripts/slave/unittests/expect_tests/handle_train.py
diff --git a/scripts/slave/unittests/expect_tests/handle_train.py b/scripts/slave/unittests/expect_tests/handle_train.py
new file mode 100644
index 0000000000000000000000000000000000000000..b918130abfaad2d1ca44c7f6ad05e43627b5b2d0
--- /dev/null
+++ b/scripts/slave/unittests/expect_tests/handle_train.py
@@ -0,0 +1,109 @@
+# Copyright 2014 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 time
+import os
+import collections
+
+from .types import Handler
+from .serialize import WriteNewData, DiffData, NonExistant, GetCurrentData
+
+
+DirSeen = collections.namedtuple('DirSeen', 'dir')
+WriteAction = collections.namedtuple('WriteAction', 'test why')
+NoAction = collections.namedtuple('NoAction', 'test')
+
+
+class TrainHandler(Handler):
+  """Write test expectations to disk."""
+  @classmethod
+  def add_options(cls, parser):
+    parser.add_argument(
+        '--force', action='store_true', help=(
+            'Immediately write expectations to disk instead of determining if '
+            'they contain a diff from the current expectations.'
+        ))
+
+  @classmethod
+  def gen_stage_loop(cls, _opts, tests, put_next_stage, put_result_stage):
+    dirs_seen = set()
+    for test in tests:
+      if test.expect_dir not in dirs_seen:
+        try:
+          os.makedirs(test.expect_dir)
+        except OSError:
+          pass
+        put_result_stage(DirSeen(test.expect_dir))
+        dirs_seen.add(test.expect_dir)
+      put_next_stage(test)
+
+  @classmethod
+  def run_stage_loop(cls, opts, tests_results, put_next_stage):
+    for test, result in tests_results:
+      if opts.force:
+        WriteNewData(test, result.data)
+        put_next_stage(WriteAction(test, 'forced'))
+        return
+
+      current, same_schema = GetCurrentData(test)
+      diff = DiffData(current, result.data)
+      if diff is not None or not same_schema:
+        WriteNewData(test, result.data)
+        if current is NonExistant:
+          why = 'missing'
+        elif diff:
+          why = 'diff'
+        else:
+          why = 'schema changed'
+        put_next_stage(WriteAction(test, why))
+      else:
+        put_next_stage(NoAction(test))
+
+  class ResultStageHandler(Handler.ResultStageHandler):
+    def __init__(self, opts):
+      super(TrainHandler.ResultStageHandler, self).__init__(opts)
+      self.dirs_seen = set()
+      self.files_expected = collections.defaultdict(set)
+      self.start = time.time()
+      self.num_tests = 0
+
+    def _record_expected(self, test):
+      head, tail = os.path.split(test.expect_path())
+      self.files_expected[head].add(tail)
+
+    # Handlers
+    def DirSeen(self, dirseen):
+      self.dirs_seen.add(dirseen.dir)
+
+    def NoAction(self, result):
+      self._record_expected(result.test)
+      if self.opts.verbose:
+        print '%s did not change' % result.test.name
+
+    def WriteAction(self, result):
+      self._record_expected(result.test)
+      if not self.opts.quiet:
+        test = result.test
+        name = test.expect_path() if self.opts.verbose else test.name
+        print 'Wrote %s: %s' % (name, result.why)
+
+    def finalize(self, aborted):
+      if not aborted and not self.opts.test_glob:
+        for d in self.dirs_seen:
+          expected = self.files_expected[d]
+          for f in os.listdir(d):
+            if f == 'OWNERS':
+              continue
+            if f not in expected:
+              path = os.path.join(d, f)
+              os.unlink(path)
+              if self.opts.verbose:
+                print 'Removed unexpected file', path
+      if not self.opts.quiet:
+        num_tests = sum(len(x) for x in self.files_expected.itervalues())
+        print 'Trained %d tests in %0.3fs' % (
+            num_tests, time.time() - self.start)
+
+
+