Check in generated Dart bindings and add presubmit script

mojo/dart/tools/presubmit/check_mojom_dart.py

Index: mojo/dart/tools/presubmit/check_mojom_dart.py
diff --git a/mojo/dart/tools/presubmit/check_mojom_dart.py b/mojo/dart/tools/presubmit/check_mojom_dart.py
new file mode 100755
index 0000000000000000000000000000000000000000..eea2ba34c20bfb73f1d1269575f7400e18f0c92b
--- /dev/null
+++ b/mojo/dart/tools/presubmit/check_mojom_dart.py
@@ -0,0 +1,191 @@
+#!/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.
+
+"""Checks that released mojom.dart files in the source tree are up to date"""
+
+import os
+import subprocess
+import sys
+
+SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
+SRC_DIR = os.path.dirname(
+    os.path.dirname(
+        os.path.dirname(
+            os.path.dirname(SCRIPT_DIR))))
+
+PACKAGES_DIR = os.path.join(SRC_DIR, 'mojo', 'dart', 'packages')
+
+# Script that calculates mojom output paths.
+DART_OUTPUTS_SCRIPT = os.path.join(SRC_DIR,
+                                   'mojo',
+                                   'public',
+                                   'tools',
+                                   'bindings',
+                                   'mojom_list_dart_outputs.py')
+
+# Runs command line in args from cwd. Returns the output as a string.
+def run(cwd, args):
+  return subprocess.check_output(args, cwd=cwd)
+
+
+def _print_regenerate_message(package):
+  print('*** Dart Generated Bindings Check Failed:')

[jamesr, 2015/11/17 01:35:07]

this is a good place to use python's """, i.e.

print("""*** Dart Generated ....
blah blah blah
blah blah blah""" % (package))

[Cutch, 2015/11/17 18:17:15]

Done.

+  print('You must regenerate bindings for %s.' % package)
+  print('From the src directory, run:')
+  print('$ dart mojo/dart/packages/mojom/bin/mojom.dart gen -m mojo/public ' +
+        '-r mojo/ --output mojo/dart/packages/');
+
+
+# Returns a map from package name to source directory.
+def _build_package_map():
+  packages = {}
+  for package in os.listdir(PACKAGES_DIR):
+    package_path = os.path.join(PACKAGES_DIR, package)
+    # Skip everything but directories.
+    if not os.path.isdir(package_path):
+      continue
+    packages[package] = package_path
+  return packages
+
+
+# Returns a list of paths to .mojom files vended by package_name.
+def _find_mojoms_for_package(package_name):
+  # Run git grep for all .mojom files with DartPackage="package_name"
+  try:
+    output = run(SRC_DIR, ['git',
+                           'grep',
+                           '--name-only',
+                           'DartPackage="' + package_name + '"',
+                           '--',
+                           '*.mojom'])
+  except subprocess.CalledProcessError as e:
+    # git grep exits with code 1 if nothing was found.
+    if e.returncode == 1:
+      return []
+
+  # Process output
+  mojoms = []
+  for line in output.splitlines():
+    line = line.strip()
+    # Skip empty lines.
+    if not line:
+      continue
+    mojoms.append(line)
+  return mojoms
+
+
+# Return the list of expected mojom.dart files for a package.
+def _expected_mojom_darts_for_package(mojoms):
+  output = run(SRC_DIR, ['python',
+                         DART_OUTPUTS_SCRIPT,
+                         '--mojoms'] + mojoms)
+  mojom_darts = []
+  for line in output.splitlines():
+    line = line.strip()
+    # Skip empty lines.
+    if not line:
+      continue
+    mojom_darts.append(line)
+  return mojom_darts
+
+
+# Returns a map indexed by output mojom.dart name with the value of
+# the modification time of the .mojom file in the source tree.
+def _build_expected_map(mojoms, mojom_darts):
+  assert(len(mojom_darts) == len(mojoms))
+  expected = {}
+  for i in range(0, len(mojoms)):
+    mojom_path = os.path.join(SRC_DIR, mojoms[i])
+    expected[mojom_darts[i]] = os.path.getmtime(mojom_path)
+  return expected
+
+
+# Returns a map indexed by output mojom.dart name with the value of
+# the modification time of the .mojom.dart file in the source tree.
+def _build_current_map(package):
+  current = {}
+  package_path = os.path.join(PACKAGES_DIR, package)
+  for directory, _, files in os.walk(package_path):
+    for filename in files:
+      if filename.endswith('.mojom.dart'):
+        path = os.path.abspath(os.path.join(directory, filename))
+        relpath = os.path.relpath(path, start=PACKAGES_DIR)
+        current[relpath] = os.path.getmtime(path)
+  return current
+
+
+# Checks if a mojom.dart file we expected in the source tree isn't there.
+def _check_new(package, expected, current):
+  checkFailure = False
+  for mojom_dart in expected:
+    if not current.get(mojom_dart):
+      print("Package %s missing %s" % (package, mojom_dart))
+      checkFailure = True
+  return checkFailure
+
+
+# Checks if a mojom.dart file exists without an associated .mojom file.
+def _check_delete(package, expected, current):
+  checkFailure = False
+  for mojom_dart in current:
+    if not expected.get(mojom_dart):
+      print("Package %s no longer has %s." % (package, mojom_dart))
+      print("Delete %s", os.path.join(PACKAGES_DIR, mojom_dart))
+      checkFailure = True
+  return checkFailure
+
+
+# Checks if a .mojom.dart file is older than the associated .mojom file.
+# TODO(johnmccutchan): Handle the case where someone edited a .mojom.dart file
+# directly instead of through the bindings generation script.
+def _check_stale(package, expected, current):
+  checkFailure = False
+  for mojom_dart in expected:

[jamesr, 2015/11/17 01:35:07]

the mix of hacker_style and camelCase is confusing - please stick to one or the
other (i.e. check_failure)

[Cutch, 2015/11/17 18:17:15]

Done. I was switching between Dart and Python yesterday.... 

+    # Missing mojom.dart file in source tree case handled by _check_new.
+    source_mtime = expected[mojom_dart]
+    if not current.get(mojom_dart):
+      continue
+    generated_mtime = current[mojom_dart]
+    if generated_mtime < source_mtime:
+      print("Package %s has old %s" % (package, mojom_dart))
+      checkFailure = True
+  return checkFailure
+
+
+# Returns True if any checks fail.
+def _check(package, expected, current):
+  checkFailure = False
+  if _check_new(package, expected, current):
+    checkFailure = True
+  if _check_stale(package, expected, current):
+    checkFailure = True
+  if _check_delete(package, expected, current):
+    checkFailure = True
+  # No check failures.
+  return checkFailure
+
+def main():
+  packages = _build_package_map()
+  checkFailed = False
+  for package in packages:
+    mojoms = _find_mojoms_for_package(package)
+    if not mojoms:
+      continue
+    mojom_darts = _expected_mojom_darts_for_package(mojoms)
+    # We only feed in mojom files with DartPackage annotations, therefore, we
+    # should have a 1:1 mapping from mojoms[i] to mojom_darts[i].
+    assert(len(mojom_darts) == len(mojoms))
+    expected = _build_expected_map(mojoms, mojom_darts)
+    current = _build_current_map(package)
+    if _check(package, expected, current):
+      _print_regenerate_message(package)
+      checkFailed = True
+  if checkFailed:
+    sys.exit(2)
+  print('OK.')
+  sys.exit(0)
+
+if __name__ == '__main__':
+    sys.exit(main())