Add a builtin repo hook to run google-java-format.

am: 0f9d9f8609

Change-Id: I931fa782b7fc9b150929c212a70d4792c9d2213e

4 files changed, 122 insertions, 0 deletions

diff --git a/README.md b/README.md
index fd3b97f..ff97bb4 100644
--- a/README.md
+++ b/README.md
@@ -148,6 +148,8 @@ canned hooks already included geared towards AOSP style guidelines.
 * `commit_msg_test_field`: Require a `Test:` line.
 * `cpplint`: Run through the cpplint tool (for C++ code).
 * `gofmt`: Run Go code through `gofmt`.
+* `google_java_format`: Run Java code through
+  [`google-java-format`](https://github.com/google/google-java-format)
 * `jsonlint`: Verify JSON code is sane.
 * `pylint`: Run Python code through `pylint`.
 * `xmllint`: Run XML code through `xmllint`.
@@ -193,6 +195,8 @@ distros/versions.  The following tools are recognized:
 * `cpplint`: used for the `cpplint` builtin hook.
 * `git-clang-format`: used for the `clang_format` builtin hook.
 * `gofmt`: used for the `gofmt` builtin hook.
+* `google-java-format`: used for the `google_java_format` builtin hook.
+* `google-java-format-diff`: used for the `google_java_format` builtin hook.
 * `pylint`: used for the `pylint` builtin hook.
 
 See [Placeholders](#Placeholders) for variables you can expand automatically.
diff --git a/rh/hooks.py b/rh/hooks.py
index 9612bf7..d92c953 100644
--- a/rh/hooks.py
+++ b/rh/hooks.py
@@ -290,6 +290,21 @@ def check_clang_format(project, commit, _desc, diff, options=None):
     return _check_cmd('clang-format', project, commit, cmd)
 
 
+def check_google_java_format(project, commit, _desc, _diff, options=None):
+    """Run google-java-format on the commit."""
+
+    if options.args():
+        raise ValueError('google-java-format check takes no options')
+
+    tool = get_helper_path('google-java-format.py')
+    google_java_format = options.tool_path('google-java-format')
+    google_java_format_diff = options.tool_path('google-java-format-diff')
+    cmd = [tool, '--google-java-format', google_java_format,
+           '--google-java-format-diff', google_java_format_diff,
+           '--commit', commit]
+    return _check_cmd('google-java-format', project, commit, cmd)
+
+
 def check_commit_msg_bug_field(project, commit, desc, _diff, options=None):
     """Check the commit message for a 'Bug:' line."""
     field = 'Bug'
@@ -512,6 +527,7 @@ BUILTIN_HOOKS = {
     'commit_msg_test_field': check_commit_msg_test_field,
     'cpplint': check_cpplint,
     'gofmt': check_gofmt,
+    'google_java_format': check_google_java_format,
     'jsonlint': check_json,
     'pylint': check_pylint,
     'xmllint': check_xmllint,
@@ -524,5 +540,7 @@ TOOL_PATHS = {
     'cpplint': os.path.join(TOOLS_DIR, 'cpplint.py'),
     'git-clang-format': 'git-clang-format',
     'gofmt': 'gofmt',
+    'google-java-format': 'google-java-format',
+    'google-java-format-diff': 'google-java-format-diff.py',
     'pylint': 'pylint',
 }
diff --git a/rh/hooks_unittest.py b/rh/hooks_unittest.py
index 0b4ef40..ec4d0b3 100755
--- a/rh/hooks_unittest.py
+++ b/rh/hooks_unittest.py
@@ -293,6 +293,12 @@ class BuiltinHooksTests(unittest.TestCase):
             self.project, 'commit', 'desc', (), options=self.options)
         self.assertEqual(ret, mock_check.return_value)
 
+    def test_google_java_format(self, mock_check, _mock_run):
+        """Verify the google_java_format builtin hook."""
+        ret = rh.hooks.check_google_java_format(
+            self.project, 'commit', 'desc', (), options=self.options)
+        self.assertEqual(ret, mock_check.return_value)
+
     def test_commit_msg_bug_field(self, _mock_check, _mock_run):
         """Verify the commit_msg_bug_field builtin hook."""
         # Check some good messages.
diff --git a/tools/google-java-format.py b/tools/google-java-format.py
new file mode 100755
index 0000000..f76175a
--- /dev/null
+++ b/tools/google-java-format.py
@@ -0,0 +1,94 @@
+#!/usr/bin/python
+# -*- coding:utf-8 -*-
+# Copyright 2016 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Wrapper to run google-java-format to check for any malformatted changes."""
+
+from __future__ import print_function
+
+import argparse
+import os
+import sys
+from distutils.spawn import find_executable
+
+_path = os.path.realpath(__file__ + '/../..')
+if sys.path[0] != _path:
+    sys.path.insert(0, _path)
+del _path
+
+import rh.shell
+import rh.utils
+
+
+def get_parser():
+    """Return a command line parser."""
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument('--google-java-format', default='google-java-format',
+                        help='The path of the google-java-format executable.')
+    parser.add_argument('--google-java-format-diff',
+                        default='google-java-format-diff.py',
+                        help='The path of the google-java-format-diff script.')
+    parser.add_argument('--fix', action='store_true',
+                        help='Fix any formatting errors automatically.')
+    parser.add_argument('--commit', type=str, default='HEAD',
+                        help='Specify the commit to validate.')
+    return parser
+
+
+def main(argv):
+    """The main entry."""
+    parser = get_parser()
+    opts = parser.parse_args(argv)
+
+    # google-java-format-diff.py looks for google-java-format in $PATH, so find
+    # the parent dir up front and inject it into $PATH when launching it.
+    # TODO: Pass the path in directly once this issue is resolved:
+    # https://github.com/google/google-java-format/issues/108
+    format_path = find_executable(opts.google_java_format)
+    if not format_path:
+        print('Unable to find google-java-format at %s' %
+              opts.google_java_format)
+        return 1
+
+    extra_env = {
+        'PATH': '%s%s%s' % (os.path.dirname(format_path),
+                            os.pathsep,
+                            os.environ['PATH'])
+    }
+
+    # TODO: Delegate to the tool once this issue is resolved:
+    # https://github.com/google/google-java-format/issues/107
+    diff_cmd = ['git', 'diff', '-U0', '%s^!' % opts.commit]
+    diff = rh.utils.run_command(diff_cmd, capture_output=True).output
+
+    cmd = [opts.google_java_format_diff, '-p1', '--aosp']
+    if opts.fix:
+        cmd.extend(['-i'])
+
+    stdout = rh.utils.run_command(cmd,
+                                  input=diff,
+                                  capture_output=True,
+                                  extra_env=extra_env).output
+    if stdout != '':
+        print('One or more files in your commit have Java formatting errors.')
+        print('You can run `%s --fix %s` to fix this' %
+              (sys.argv[0], rh.shell.cmd_to_str(argv)))
+        return 1
+
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv[1:]))