Moving mojo/validation test into LayoutTests

mojo/public/interfaces/bindings/tests/gen_data_files_list.py

+# Copyright 2017 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.
+"""Generates the data file directory to run validation tests.
+
+This script finds all of the files in the resources/data/validaiton folder

[yzshen1, 2017/03/23 17:46:20]

A few ideas:
- This script could be a generic tool which lists all files (or use a filter
pattern to selectively list files) in a given folder. And it could live in
mojo/public/tools/bindings/

- There is no need to copy files in this script. That could be done using "copy"
GN rule. 

- Please use OptionParser instead of directly use sys.argv.

- Please use the following pattern:

define main():
  ...

if __name__ == '__main__':
  sys.exit(main())

[damargulis, 2017/03/24 19:44:48]

I moved this file into mojo/public/tools/bindings, but since I was unable to get
the copy gn action to work for this task (as explained in the other comment), I
am still copying all of the files in this script.  If we can't get copy to work
and use this script to copy the files, does it still make sense to use this as a
tool, or does it become too specific of a task?  Additionally, I could create
two python actions, one to create the list and another to copy all of the files
in that list.  Both of those scripts could then live in the tools/ directory.  

+and generates a file listing all of those files.  That file is then consumed
+by the validation test so that it can locate and fetch all data files.
+"""
+
+from os import listdir, makedirs, path
+from shutil import copy
+import sys
+
+def gen_files():
+  files = [ f[:-5] for f in listdir(sys.argv[1]) if f.endswith('.data') ]

[yzshen1, 2017/03/23 17:46:20]

Does listdir() return absolute path or relative path? Please make sense those
path are relative. Because it is possible that when the tests are run on bots,
the output folder (or part of it) is copied to another machine with a different
path.

[damargulis, 2017/03/24 19:44:48]

listdir() takes in a relative path, and returns only the file names and
extensions.  The output validation_files.txt only lists the file names and
extensions.  In the tests, the directory is specified using /gen/ which gets
converted through your patch to point to the correct generated directory. 

+  out = file(sys.argv[2], 'w')
+  output_dir = sys.argv[2].rsplit('/', 1)[0] + '/data'
+  if not path.exists(output_dir):
+    makedirs(output_dir)
+  with out:
+    for f in files:
+      copy(sys.argv[1] + '/' + f + '.data', output_dir)
+      copy(sys.argv[1] + '/' + f + '.expected', output_dir)
+      out.write(f + '\n')
+
+gen_files()