rebaseline_server: extract common unittest code, and rename tests/ -> testdata/

gm/rebaseline_server/base_unittest.py

Index: gm/rebaseline_server/base_unittest.py
diff --git a/gm/rebaseline_server/base_unittest.py b/gm/rebaseline_server/base_unittest.py
new file mode 100755
index 0000000000000000000000000000000000000000..172a8c0ed913853f63157f6bf59ae77e8008e61f
--- /dev/null
+++ b/gm/rebaseline_server/base_unittest.py
@@ -0,0 +1,100 @@
+#!/usr/bin/python
+
+"""
+Copyright 2014 Google Inc.
+
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file.
+
+A wrapper around the standard Python unittest library, adding features we need
+for various unittests within this directory.
+"""
+
+import filecmp
+import os
+import shutil
+import tempfile
+import unittest
+
+PARENT_DIR = os.path.dirname(os.path.realpath(__file__))
+TESTDATA_DIR = os.path.join(PARENT_DIR, 'testdata')

[epoger, 2014/02/18 20:27:02]

This is the only *code* change in patchset 2: modify 'tests' string to
'testdata'.

+OUTPUT_DIR_ACTUAL = os.path.join(TESTDATA_DIR, 'outputs', 'actual')
+OUTPUT_DIR_EXPECTED = os.path.join(TESTDATA_DIR, 'outputs', 'expected')
+
+
+class TestCase(unittest.TestCase):
+
+  def setUp(self):
+    self._input_dir = os.path.join(TESTDATA_DIR, 'inputs')
+    self._output_dir_actual   = os.path.join(OUTPUT_DIR_ACTUAL, self.id())
+    self._output_dir_expected = os.path.join(OUTPUT_DIR_EXPECTED, self.id())
+    create_empty_dir(self._output_dir_actual)
+    self._temp_dir = tempfile.mkdtemp()
+
+  def tearDown(self):
+    shutil.rmtree(self._temp_dir)
+    if os.path.exists(self._output_dir_expected):
+      different_files = find_different_files(self._output_dir_actual,
+                                             self._output_dir_expected)
+      # Maybe we should move this assert elsewhere?  It's unusual to see an
+      # assert within tearDown(), but my thinking was:
+      # 1. Every test case will have some collection of output files that need
+      #    to be validated.
+      # 2. So put that validation within tearDown(), which will be called after
+      #    every test case!
+      #
+      # I have confirmed that the test really does fail if this assert is
+      # triggered.
+      #
+      # Ravi notes: if somebody later comes along and adds cleanup code below
+      # this assert, then if tests fail, the artifacts will not be cleaned up.
+      assert (not different_files), \
+        ('found differing files between actual dir %s and expected dir %s: %s' %
+         (self._output_dir_actual, self._output_dir_expected, different_files))
+
+  def shortDescription(self):
+    """Tell unittest framework to not print docstrings for test cases."""
+    return None
+
+
+def create_empty_dir(path):
+  """Create an empty directory at the given path."""
+  if os.path.isdir(path):
+    shutil.rmtree(path)
+  elif os.path.lexists(path):
+    os.remove(path)
+  os.makedirs(path)
+
+
+def find_different_files(dir1, dir2, ignore_subtree_names=None):
+  """Returns a list of any files that differ between the directory trees rooted
+  at dir1 and dir2.
+
+  Args:
+    dir1: root of a directory tree; if nonexistent, will raise OSError
+    dir2: root of another directory tree; if nonexistent, will raise OSError
+    ignore_subtree_names: list of subtree directory names to ignore;
+          defaults to ['.svn'], so all SVN files are ignores
+
+  TODO(epoger): include the dirname within each filename (not just the
+  basename), to make it easier to locate any differences
+  """
+  differing_files = []
+  if ignore_subtree_names is None:
+    ignore_subtree_names = ['.svn']
+  dircmp = filecmp.dircmp(dir1, dir2, ignore=ignore_subtree_names)
+  differing_files.extend(dircmp.left_only)
+  differing_files.extend(dircmp.right_only)
+  differing_files.extend(dircmp.common_funny)
+  differing_files.extend(dircmp.diff_files)
+  differing_files.extend(dircmp.funny_files)
+  for common_dir in dircmp.common_dirs:
+    differing_files.extend(find_different_files(
+        os.path.join(dir1, common_dir), os.path.join(dir2, common_dir)))
+  return differing_files
+
+
+def main(test_case_class):
+  """Run the unit tests within the given class."""
+  suite = unittest.TestLoader().loadTestsFromTestCase(test_case_class)
+  results = unittest.TextTestRunner(verbosity=2).run(suite)