Sync: Generalize entity injection in Android tests

sync/protocol/prepare_protos_for_java_tests.py

Index: sync/protocol/prepare_protos_for_java_tests.py
diff --git a/sync/protocol/prepare_protos_for_java_tests.py b/sync/protocol/prepare_protos_for_java_tests.py
new file mode 100755
index 0000000000000000000000000000000000000000..0db4b9dc11625b6ed372935a66118925a8c4e9b4
--- /dev/null
+++ b/sync/protocol/prepare_protos_for_java_tests.py
@@ -0,0 +1,76 @@
+#!/usr/bin/env python
+# Copyright 2015 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.
+
+"""Converts protocol buffer definitions to ones supported by the Nano library.
+
+Note: Java files generated from the output of this script should only be used
+in tests.
+
+Chromium uses the Java Protocol Buffers Nano runtime library. This library,
+compared to the standard proto compilter in C++, is limited. Most notably, the
+retain_unknown_fields option is not supported.
+
+This script also adds Java-specific configs to enable usage in Java. This script
+is Sync-specific, so a Sync package name is used.
+"""
+
+import optparse
+import os
+import re
+import sys
+
+
+def main():
+  parser = optparse.OptionParser(
+      usage='Usage: %prog [options...] original_proto_files')
+  parser.add_option('-o', '--output_dir', dest='output_dir',
+                    help='Where to put the modified proto files')
+
+  options, args = parser.parse_args()
+  if not options.output_dir:
+    print 'output_dir not specified.'
+    return 1
+
+  # Map of original base file names to their contents.
+  original_proto_contents = {}
+  for original_proto_file in args:
+    with open(original_proto_file, 'r') as original_file:
+      base_name = os.path.basename(original_proto_file)
+      original_proto_contents[base_name] = original_file.read()
+
+  for file_name, original_contents in original_proto_contents.iteritems():
+    new_contents = ConvertProtoFileContents(original_contents)
+    with open(os.path.join(options.output_dir, file_name), 'w') as new_file:
+      new_file.write(new_contents)
+
+
+def ConvertProtoFileContents(contents):

[Nicolas Zea, 2015/04/09 20:38:16]

I wonder if we should have a test for this? Although I guess if a bug were to be
introduced here the compiles would fail, right?

[pval...(no longer on Chromium), 2015/04/09 21:28:05]

Yes, compilation would fail. However, that's no guarantee this script works as
100% intended. There is precedence for adding a build process Python test (see
this change: https://codereview.chromium.org/896663002).

Thoughts?

[Nicolas Zea, 2015/04/09 21:40:42]

As long as compile would fail I think we're fine (and that the targets that
would fail are part of the normal trybots, which they are).

+  """Returns a Nano-compatible version of contents.
+
+  Args:
+    contents: The contents of a protocol buffer definition file.
+  """
+  # Remove the retain_unknown_fields option.
+  incompatible_option_regex = re.compile(
+      r'^\s*option\s+retain_unknown_fields\s*=.*;', re.MULTILINE)
+  pruned_contents = incompatible_option_regex.sub('', contents)
+
+  # Add the java_multiple_files and java_package options. Options must be set
+  # after the syntax declaration, so look for the declaration and place the
+  # options immediately after it.
+  # TODO(pvalenzuela): Set Java options via proto compiler flags instead of
+  # modifying the files here.
+  syntax_regex = re.compile(r'^\s*syntax\s*=.*;', re.MULTILINE)
+  syntax_end = syntax_regex.search(pruned_contents).end()
+  java_options = ('option java_multiple_files = true; '
+                  'option java_package = "org.chromium.sync.protocol";')
+
+  contents_to_join = (pruned_contents[:syntax_end], java_options,
+                      pruned_contents[syntax_end:])
+  return ''.join(contents_to_join)
+
+
+if __name__ == '__main__':
+  sys.exit(main())