Add a script to print js closure-style dependencies.

chrome/browser/resources/chromeos/chromevox/tools/print_js_deps.py

+#!/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.
+
+'''Print the dependency tree for a JavaScript module.
+
+Given one or more root directories, specified by -r options and one top-level
+file, walk the dependency tree and print all modules encountered.
+A module is only expanded once; on a second encounter, its dependencies
+are represented by a line containing the characters '[...]' as a short-hand.
+'''
+
+import optparse
+import os
+import sys
+
+from jsbundler import ReadSources
+
+
+def Die(message):
+  '''Prints an error message and exit the program.'''
+  print >>sys.stderr, message
+  sys.exit(1)
+
+
+def CreateOptionParser():
+  parser = optparse.OptionParser(description=__doc__)
+  parser.usage = '%prog [options] <top_level_file>'
+  parser.add_option('-r', '--root', dest='roots', action='append', default=[],
+                    metavar='ROOT',
+                    help='Roots of directory trees to scan for sources. '
+                    'If none specified, all of ChromeVox and closure sources '
+                    'are scanned.')
+  return parser
+
+
+def DefaultRoots():
+  script_dir = os.path.dirname(os.path.abspath(__file__))
+  source_root_dir = os.path.join(script_dir, *[os.path.pardir] * 6)
+  return [os.path.relpath(os.path.join(script_dir, os.path.pardir)),
+          os.path.relpath(
+            os.path.join(source_root_dir, 'chrome', 'third_party',
+                         'chromevox', 'third_party',
+                         'closure-library', 'closure'))]
+
+
+def WalkDeps(sources, start_source):
+  def Walk(source, depth):
+    indent = '  ' * depth
+    if source.GetInPath() in expanded and len(source.requires) > 0:
+      print '%s[...]' % indent
+      return
+    expanded.add(source.GetInPath())
+    for require in source.requires:
+      if not require in providers:
+        Die('%s not provided, required by %s' % (require, source.GetInPath()))
+      require_source = providers[require]
+      print '%s%s (%s)' % (indent, require, require_source.GetInPath())
+      Walk(require_source, depth + 1)
+
+  # Create a map from provided module names to source objects.
+  providers = {}
+  expanded = set()
+  for source in sources.values():
+    for provide in source.provides:
+      if provide in providers:
+        Die('%s provided multiple times' % provide)
+      providers[provide] = source
+
+  print '(%s)' % start_source.GetInPath()
+  Walk(start_source, 1)
+
+
+def main():
+  parser = CreateOptionParser()
+  options, args = parser.parse_args()
+  if len(args) != 1:
+    Die('Exactly one top-level source file must be specified.')
+  start_path = args[0]
+  roots = options.roots or DefaultRoots()
+  sources = ReadSources(roots=roots, source_files=[start_path])
+  start_source = sources[start_path]
+  WalkDeps(sources, start_source)
+
+
+if __name__ == '__main__':
+  main()