Add a script to update Flutter dart dependencies. (flutter#78)

Author: aam

tools/dart/create_updated_flutter_deps.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python
+# Copyright 2017 The Dart project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Usage: tools/dart/create_updated_flutter_deps.py [-d dart/DEPS] [-f flutter/DEPS]
+#
+# This script parses existing flutter DEPS file, identifies all 'dart_' prefixed
+# dependencies, looks up revision from dart DEPS file and prints a list of updated
+# revision to the console so it can be copy'n'pasted into flutter DEPS file.
+
+import argparse
+import os
+import sys
+
+DART_SCRIPT_DIR = os.path.dirname(sys.argv[0])
+DART_ROOT = os.path.realpath(os.path.join(DART_SCRIPT_DIR, '../../dart'))
+FLUTTER_ROOT = os.path.realpath(os.path.join(DART_SCRIPT_DIR, '../../flutter'))
+
+class VarImpl(object):
+  def __init__(self, local_scope):
+    self._local_scope = local_scope
+
+  def Lookup(self, var_name):
+    """Implements the Var syntax."""
+    if var_name in self._local_scope.get("vars", {}):
+      return self._local_scope["vars"][var_name]
+    raise Exception("Var is not defined: %s" % var_name)
+
+
+def ParseDepsFile(deps_file):
+  local_scope = {}
+  var = VarImpl(local_scope)
+  global_scope = {
+    'Var': var.Lookup,
+    'deps_os': {},
+  }
+  # Read the content.
+  with open(deps_file, 'r') as fp:
+    deps_content = fp.read()
+
+  # Eval the content.
+  exec(deps_content, global_scope, local_scope)
+
+  return local_scope.get('vars', {})
+
+def ParseArgs(args):
+  args = args[1:]
+  parser = argparse.ArgumentParser(
+      description='A script to generate updated dart dependencies for flutter DEPS.')
+  parser.add_argument('--dart_deps', '-d',
+      type=str,
+      help='Dart DEPS file.',
+      default=os.path.join(DART_ROOT, 'DEPS'))
+  parser.add_argument('--flutter_deps', '-f',
+      type=str,
+      help='Flutter DEPS file.',
+      default=os.path.join(FLUTTER_ROOT, 'DEPS'))
+  return parser.parse_args(args)
+
+def Main(argv):
+  args = ParseArgs(argv)
+  new_deps = ParseDepsFile(args.dart_deps)
+  old_deps = ParseDepsFile(args.flutter_deps)
+  for (k,v) in sorted(old_deps.iteritems()):
+    if k != 'dart_revision' and k.startswith('dart_'):
+      v = '???'
+      dart_key = k[len('dart_'):]
+      updated_revision = new_deps[dart_key].lstrip('@') if new_deps.has_key(dart_key) else v
+      print "  '%s': '%s'," % (k, updated_revision)
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(Main(sys.argv))